@@chrisl4999 it can be hard to think about because with the little packets there is no obvious change if they are dry or wet (other than weight but the change is too small and gradual for most people to notice). Something that is much easier to visualise is dehumidifiers, both the since use ones and electric ones. The single use ones for use in cupboards and closets and similar typically have an area of desiccant and a tank for liquid underneath. Over time the desiccant disappears and the tank fills up, I don’t know what desiccant they use though. Electric dehumidifiers work different and don’t use desiccant but you can see just how much moisture they pull out of the air. It is very surprising how much they can pull out that quickly.
It's very funny to observe chinese worker's action who"s getting SG bags out of the big uncovered basket stayed here for several days at almost 100% relative humiduty of the air of the South China, and putting it to the sealed packaging together with the product.
urgent safety warning, since you missed it some desiccant is based on calcium chloride, like the packs Bambu Lab sells for their AMS calcium chloride is very potent in chemically binding water, it is not just absorbing it it theoretically can be regenerated, but when you heat it too fast, it will decompose partially into hydrochloric acid the temperature window is quite small, so absolutely do not do this at home, you don't want to inhale hydrochloric acid fumes how does it look? it is usually a white-ish powder, like powdered sugar or flour and when saturated it turns a bit yellowish, sometimes it also looks porous like the kitty litter stuff - you can buy those in large quantity for passive dehumidifiers but you absolutely need to discard those after use
Good to know. I've "successfully" regenerated damp-rid in a stainless steel pot on a hot plate indoors twice, but at the time didn't know why the "odor" it gave off made it hard to breathe. I didn't get any long term ill effects from doing it, and I also smoke like a chimney. I suspect of all the acidic gasses a person can inhale, hydrogen chloride is probably not terrible in low concentrations, because that's also what stomach acid is. It makes sense the body can handle it in the wrong places in small amounts. I'm not recommending doing it though. Inhaling HFl is relatively worse. A decade ago I was cleaning mineral build up off of a pair of storm windows and had the bright idea to lay the windows flat and cover them in Wink cleaner (nothing else was working). In hindsight I'm not sure how I survived inhaling HFl fumes for half an hour as I was leaning over those windows scrubbing them. It did do a great job of cleaning the glass, but it was also probably etching it slightly and definitely burning my lungs. I'm sure breathing acid isn't the dumbest thing I've ever done, and it happens to a lot of other people who don't figure out it's bad and keep doing it until it messes them up.
@@chrisbalfour466 the fumes won't kill you and it probably won't have any long term negative effects, but still you don't want to inhale it if you don't need to lots of household chemicals include hydrochloric acid, like cement stain remover for example - it is just nasty
@@suit1337 "t probably won't have any long term negative effects" except the iron/steel (e.g. pliers, cast iron pots/black steel pans, things like this) may start to rust a lot faster even from the air moisture. Ferous chloride is hygroscopic and the chlorine ions act as a catalyst for the rusting process.
I've been drying silica packets in the microwave for a while now and I'd like to share a couple of tips. 1/ After you thoroughly dry a sachet for the first time weigh it and write that on it with a marker, then later you can easily find out if it needs a refresh by how much weight it has gained. If you have kitchen scales this only really works for larger packs (25g+), for smaller packs you need more sensitive scales. This also helps with the drying process as you can sse how it's going by measuring in between cycles in the microwave 2/ Put a paper towel under the sachets in the microwave, it will significanly reduce the chance of melting the bag vs putting them straight on the glass turntable. 3/ Give the sachets a good shake in between cycles in the microwave, particularly the first couple, it helps get the steam/moisture out through the bag.
I am surprised this works. We dry silica with heat at the lab (electric drying furnace at 100C/212F for 24h), so drying it in a gas oven was impractical, plus the risk of flames. I thought microwaves could be too intense and would cause the beads to pop, making it much less effective by absorbing humidity too fast (simply taking it out of the microwave would render it useless). I guess it works!
Good tips. Those tiny $10 digital scales are all really good. I've been using them for years. Compared with my sensitive gram scales in my science classroom, they were within 1%. I might be responsible for spreading the 'rice thing.' In 2000 I was hiking in Yunnan China and got wet in stream at Tiger Leaping Gorge. The felt light block on the film cassette was wet. So back at Tina's (still there) I asked for some dry rice. I knew that uncooked rice is hydroscopic. I packed the film in this in a canister until I got home in the states. Then chatting with friends in our online group the subject of wet electronics came up, so I shared the tip. (I can't be the first because it's so obvious.) We decided that a vacuum with heat would be good, and that in a pinch uncooked rice might help.... So I wrote it up and shared it around the internet. 15 years later I went into the AT&T store said I dropped my phone in the ocean and... the clerk interrupted me telling me the rice method. I swear it was almost verbatim what I'd written. But that can't be possible..... Later when I switched to another carrier I asked about what to do if a phone got wet.... This clerk told me about the rice, but it was more general. So maybe.... Then Louis Rossmore who complains endlessly and occasionally fixes laptops had an entire episode haranguing how stupid the rice method was.... I think I turned it off when he was shouting that dried rice won't cure herpes.... But rice is basically similar to these products in this video. So where they work, rice would work. Searching the internet I've found some links that say rice isn't as good as silica gel and some that say it is. The big difference my friends back in the old millennium decided was, you wouldn't use rice because being edible it would attract vermin (rats like dry rice). I think an ideal method would be to 1. figure out how to safely use your microwave. 2. figure out a way to remove the humidity in the microwave. I might try putting heated desiccant bags in a vacuum bag and run the cycle of my vacuum sealer (You could also use a zip lock bag by cutting off the sealing strips and turning them sideways to make a gap to suck out all the air. 3. Set up a schedule. Write on the bags the weight (great tip! thanks) but also a date, and then put a schedule in your schedule App. (I've been terrible with my lithium batteries not using a camera for many months and killing the battery.) Then weight them or just run them through the drying cycle. Weighing them you might decide the time between drying can be extended. But if you just do this every couple of months, or have a supply of extra bags on hand... it should be easy.
Panasonic microwaves use inverters instead of transformers and can actually output a percentage of the power vs full power on/off. I think there are now other manufacturers who use inverters, but it's good to know that they're out there and work significantly better than transformer-based microwaves for less-than-100% output, which generally works a lot better for heating food more evenly. I imagine it would work better for regenerating desiccant as well.
Love my Panasonic microwave with inverter. Best microwave we've ever owned. It's sensing feature for heating food is really good also. It's what I use it for the most, reheating.
Here's More Panasonic love and encouragement to try a drying test. With an outlet store discount and an eBay discount, it still wasn't cheap, but it's a combi, and I use it almost every day, so it was worth it! As a combi oven, it raises the question of a drying test with microwaves, temperature-controlled oven and even grill?
Funny to think that what an inverter does is switch the power supply on and off to give an average that is less than full power.... exactly what traditional microwaves are doing with the microwave gun. Just inverters do it in the kHz or mhz range. Exactly the same technique, just faster.
I used to work on a satellite uplink/downlink dish that used rectangular waveguides that were kept slightly pressurized to prevent moisture from collecting in it. The intake to the air pump had a bottle of blue indicating silica gel. As part of the scheduled preventative maintenance we'd swap out the beads and then microwave them until they turned blue again, and store it in a screw-top jar until next time.
There is a way easier way to judge if the gel or clay is saturated or not. Just throw it into an oven at 110 degrees until they are heated and then hold them against a cold surface like a mirror or window. If the window shows signs of condensation, they are wet. If not they are dry. I have a couple of 1 kg clay bags that I throw into the oven every now and then overnight and when they stop causing condensation on the mirror, they are dry. Thats it, back into the box with the filaments. 2 kg of clay is sufficient to keep the filament dry for a couple of months to a year.
I simply weigh the bag. I know the weight when it's dry, it's about 1kg in my case. I used these to get the moisture out of the car. The weight has gone up to 1.4kg.
my theory on the microwave being so effective is that it's because of how microwaves heat things. They literally heat the water molecules, and in this case, boiling off the water is exactly what we're trying to accomplish. All the other methods are radiative/conductive heat which has to heat the entire mass up to the boiling point of water (or whatever the temperature that the desiccant releases water at) in order to get rid of it, whereas the microwave selectively targets the water just by being a microwave.
@@bepstein111 Of course but it's also the downside because microwaves don't necessarily heat everything in them evenly, especially the cheap ones we'd likely use for this. That leads to hot spots and likely why he always heard some cracking. That's not to say it isn't useful but I'm not a fan of using it for larger quantities if dessicant. I'd be curious to see someone put together a design out of old microwave parts that's meant specifically for dessicant (or even filament drying)..
It's a myth microwaves only heat water. They will hear anything with a dipole moment. Such as fats and oils. Or in this video, clay that probably had some iron contamination.
I think it might be worth mentioning: Don't disassemble a microwave if you aren't *very* familiar with how they work. They have a very large capacitor and can keep a lethal amount of electricity for a surprisingly long time. Attempting to make a desiccant re-furbisher while on the wrong side of the Dunning-Kruger effect has an extremely high chance of being the last project you work on.
@@Sylfa Yes it's easy to forget that someone might actually attempt a shower thought comment. While I'd hope anyone who'd even think about such a niche project knows how to discharge a cap, screwing with microwaves is a whole other can of worms. I work with electronics for a living and aren't afraid to admit that doing this safely is well outside my wheelhouse.
@@JJFX- I figure the risk of someone seeing it and actually doing it was minimal, but like with Lichtenberg wood burning disassembling microwaves falls into things that keeps cropping up in various contexts and hobbyists completely fail to see the risks involved.
Nice thorough bit of testing. I've been using my microwave to dry bulk silica gel, but at full power, which may not be great for the gel or the microwave itself. The defrost mode is a good idea. I also recently got a cheap air fryer to test as a dedicated dryer, making sure it never gets contaminated with oils from previous food use.
I´d personally use the food dehydrator with stackable plates. That might work well. Anyway, I did the exact same thing with microwave and the beads just cracked and exploded because the microscopic pores well suddenly full of steam.
Thanks! I recently figured this out - that my desiccant was adding moisture to filament that I had just removed from the dryer. Your advice on how to dry the used desiccant will be very helpful and I will put it to use immediately!
Hello. I would like to add some information to the test, especially since I personally use 1 kg silica gel dessicant bag for my car (reusable): -In large quantities (like 1 kg) you can genuinely blast silica at full power bursts for 2-5 minutes, because the energy is more dispersed, and therefore power density is lower. -There are large reusable silica dessicant bags (1kg) available as "car dehimidifier", they even have heat-proof indicator that mostly works (Limpro for example) -You do not need to heat the silica so much - even temperature above 50-60°C will start pushing the moisture out. I recommend: Buying 1 kg reusable bags for cars (indicator not necessary) Drying in microwave on full power for less than 3-4 minutes each time Place it in microwave on some kind of rack made of cardboard or similar, so that the bag gets better air flow 1 kg of silica in my case contains ~200-250g of water after full use, so it will take a while to remove all of it - 3-5 cycles with long breaks inbetween. P.S. 1kg dehumidifier should cost as little as 5€.
It's not crystal, it's also silicagel. I've tossed some in my passive dryboxes and it seems to work fine though the overall moisture level in my apartment is just high.
Stefan, there is another option for testing the moisture levels in your desiccant that I use in my lab to check if my cement sand is microwave dried. Take a strip of plain paper, approximately 8 cm in length by 2 cm wide. Place it on top of your desiccant. If the paper starts to curl at the ends, it still has moisture. The humidity will warp the paper. It's a small trick, low tech, but it works very well.
Wow! This is super helpful. To be fair it is CNC Kitchen is one of the keys to me having success 3D Printing. Thank you again Stephan for upgrading my 3D prints.
Thanks so much! I’ve been buying bulk 100% silica gel kitty litter and drying it in the oven. I fill up an old cotton sock and use that as my desiccant pack. Going forward, I’ll be using the microwave to dry the silica in a much shorter time.
I work on large electronics and often get 200g desiccant bags. I throw them in a box and once I get a nice supply I dry them out in the oven per the MIL-D-3464 spec of 245f for 16 hours. After that I use them in my tool boxes to keep rust away and in my filament dry boxes in lieu of buying new. Quick edit: I was an Aircraft Mechanic in the Air Force, we actually used the microwave method to quickly dry out the desiccant used for one of the avionics unit on board.
Those big bags are great for storing marine electronics like hand held VHF. After a kayaking trip rinse the set with corrosion inhibitor and seal into a lever lock box. WiseDry always give you the pack weight so you can check weigh moisture content. My tip is BUY NEW SACHETS. They are cheap enough. Being a cheap skate is dumb. This content creator seems to feel cheated because the sachet has already done its job when he opens the bag of filament but he is too mean to toss it away - - like it says to do on the packet !!
I solved this problem by living in a desert. Ten percent relative humidity for 90% of the year makes it pretty easy to keep things dry. I would add something like paper towels to the microwave to help soak up the moisture you're vaporizing out of the desiccant.
The desert is not always the best solution. I'm in Scottsdale, and today its 48% outside. Even when its 10% it often is much higher inside. 35% typical in my house, and in in the winter I add a humidifier so it raises to maybe 45%. Much too high for filament. True, its not Florida, or Texas.
@@A1N0 Of course the humidity will be increased when it rains in the area, but most of the year it is 10%. My house isn't any more humid nor is my garage. If you're maintaining that much humidity in your house when it's 10% outside, you likely are cooling with a swamp cooler. An AC isn't a dehumidifier, but it does help pull humidity out of the air.
@@3nertia It's literally not a dehumidifier. It is specifically designed to cool air and just pulls some moisture out of the air due to the cooling effect. A dehumidifier is specifically designed to pull moisture out of the air.
@@fokker1138 What a coincidence because a dehumidifier and air conditioner contain the exact same components operating the exact same way lmfao It's almost as if someone made a "dehumidifier" and then they realized it had an "evaporative cooling" effect that could be utilized as an "air conditioner" ....
I have been drying my descant in the microwave oven for years, it is really fast. However, a solution to not having it "over cook" the desiccant (ie melt plastic bags) is to just add more desiccant. As in a lot more. As long as one can spread it out as a suitably "thin" (an inch is adequate) layer it is fine, and the wonderful wire rack one gets with some microwave ovens meant for having two plates in the oven at once is a great way to double the amount of available area without hindering the microwave's ability to heat everything "evenly". Simply stated, the microwaves are going to dump all their energy wherever available, where the most RF absorbent material takes the most of the available energy, luckily enough that is most often water. So give it more desiccant to spread the energy into. Downside is that it won't dry your desiccant as quickly, but given the fact that it is already practically "instant" compared to other methods, this isn't really much of a downside. Another method is to babysit the oven and manually pulse it between on and off if one has too little desiccant. After all, you don't want too much heat. However. Heating it in an oven is far easier to not overheat it. An oven set to 110 C won't magically get to 150+ C, unlike the microwave oven that just dumps X watts into its interior almost regardless of internal temperatures. (though if there is too little in there to absorb the RF energy, the magnetron will usually heat up instead until its thermal fuse saves the day.)
One thing to keep in mind with a microwave is to be very careful to do it as slowly as possible. Setting the microwave to the lowest setting is the best way because microwave ovens from different manufactures operate differently on defrost. Some on a defrost setting will at first kick the power up a bit for the first couple of minutes, then slowly decrease it. This is the opposite of what we want, because heating silica too quickly, while saturated, allows the water to boil inside the Silica Gel bead and with the massive expansion of the steam, can't escape the microscopic "holes" in them fast enough and they will crack and split, damaging them and making them far less effective.
Indeed. I’m not sure why people are recommending the defrost setting when most microwaves have a literal power level setting, which is a much more direct and reliable way of achieving what we want: low power. (Unless the power level setting isn’t actually as common on microwaves as I’m imagining?)
Why would breaking the silica into smaller pieces make them less effective? I'd think the opposite, as the smaller pieces would make the escape path for the water shorter.
@@nlkatz Here is the theory: Silica gel is made of silicon dioxide and is highly porous, with millions of tiny pores that can capture and hold moisture. Water molecules are drawn into the pores by capillary action, and then held there until released. If these pores or capillaries are made larger by chipping from rapid expansion by steam, they are no longer small enough to absorb and hold the water. You are right though. Smaller pieces can absorb quicker since they have more surface area exposed. But the breaking is more at the microscopic pores level and is where the problem is. On a related topic, I think the benefit of small beads versus larger ones also depends on air flow. Larger beads allow more air to flow around them and may work better where there is little airflow. If you have lots of airflow, the smaller beads definitely will work better. I tested this in a container filled with Silica Gel using forced air. The smaller beads worked way quicker. But without the forced air, the bigger beads worked quicker. If there was interest, I'd do a video on my sealed filament cabinet with a forced air silica gel based dryer. I even have an app that tracks the humidity and can regulate it at a specific percentage by turning the fan on/off using a "humidistat" (made with a BMSE680 and Arduino) . When the Silica is fresh the fan only runs very periodically, but as it becomes closer to saturation the fan rate increases to maintain a steady humidity level. Fun stuff...
@@triadxtechnologies That theory doesn't hold water. Literally; capillary action works only with liquids, and we're dealing with vapor; I believe the correct term for what's happening here is adsorption. I agree that at some point breaking into too many pieces will reduce the number of pores available to capture the vapor.
@@nlkatz You are absolutely right. Adsorption is the dominant force taking place. While capillary action helps draw water into the pores, the primary mechanism at play is capillary condensation. This occurs when the vapor pressure of water within the pores is higher than the surrounding environment, leading to condensation of water vapor into liquid water within the pores. Alongside capillary condensation, adsorption is the dominant force. Anyhow, the point I was making is by heating too fast can damage its porous structure.
Dunno if I missed it in the video, but I gather the silica gel pores start to close over about 90 deg C. At around 18:30 I saw the silica hit 130 deg C in the microwave which I think would largely destroy its ability to collect moisture because all the pores will close. I think the microwave is probably excellentwith the right method. The brisket bbq people have the right idea "low and slow". I am personally fascinated by the way a refrigerator and freezer dry things out. It might be an equally useful method to dry the silica without risk of thermal degradation.
Thanks for this. I have been using the bags without drying them first. No more! I also have been using Eibos plastic bags for storage that have a threaded opening where air can be evacuated. I then made a part that attaches to my vacuum cleaner to create the vacuum inside the bag. Now with this knowledge, the bags will keep dryer.
There is one more method that might work for you: vacuum+heat. This is widely used in the drying of exotic high-value timber and is able to bring saturated wood down to 10-15% moisture in rather quckly without inducing stresses (if done properly of course). Vacuum kilns are not exactly common, being quite expensive to set up, but they are probably the most effective way of quickly drying fresh timber which is basically a big water-soaked sponge.
I was going to suggest this myself. I haven't tried it yet, but in theory, nearly 100% of the water content could be removed from the descant in a vacuum at room temperature. It would probably also be the most energy efficient method for removing moisture. At a modest vacuum of 5% atmospheric pressure, all of the water should "boil" out of the desiccant over a short period of time. The maximum dryness would be indicated when the static pressure of the vacuum container stopped rising (when not actively pumping), and of course the weight of the container could be monitored as well.
Glad you told people not to do it on full power because I tried that before, thought it would speed things up - and it overheats the granules and cracks them.
I have bags that have special valves for vacuuming them. In spite of being adhesive based, it's remarkably effective. I had a spool of PETG that was still almost too vaccumed after sitting on a shelf for over a year. The bags that come with filament don't have this feature.
Just the video I needed right know. I am in a whole rebuilding process of my 3D printer and workflow and would like to print materials which are need to be stored dry. So I was thinking of how reliable are the reused gels etc. Basically which you covered all. These measurements and tests are so valuable for the community and you do win us time and money with this work. So I wish you great success in the future and thank you!
I worked at hardware stores and they literally toss out these baggies nearly every night. Pounds and pounds of them. So I asked if I could just take them with me, and they said sure - since they were just trash they were paying to haul off. Now I have like 5lbs of the stuff to work with, for free. I have been using a little toaster oven but I think I might hit them with microwave first, then some toaster time before going into a sealed container until use. Benefits from both, the quick 5 minute defrost time- then bop em in the oven for a while and let slow release the rest.
After trying a lot of options I've settled on using a cheap air fryer. Microwaves work great but it's hard not to get hot spots and damage them. The air fryer at lower temps not only dries it faster than an oven but it evacuates the air out the back which you could probably use to measure how much moisture is coming out. I use an aluminum baking tray that I punched a bunch of holes in with a thumb tack to let the air pass through and you could optimize this further for drying a thick layer of dessicant. Back in the day I had a combo toaster that used low power microwaves and heat to cook faster which would be really interesting to try but this concept seems uncommon now for some reason.
I just dried mine in an air fryer and my fancy air fryer can only run for 1hr max but it has a dehydrator setting that can run for 8hrs which would be total overkill for desiccant but works for filament spools.
@@boilerbots Well not sure how much you're trying to dry but I've never needed that much time. Mine can operate between 150-400F and the dehydrate option starts at 1hr and allows 1 hr increments from there. If I'm drying a thick tray of dessicant I'd want to occasionally stir it anyway. I've stuck a temperature probe in the dessicant and (at least for my setup) found you can set the temp notably higher than what it's actually getting to.
This! Air fryer is the one he didn’t test and the one that works excellently, simply the best for the reasons you pointed out. Works even better with the clay too, oil dry is great option.
Air fryers aren't fryers, they are small countertop convection ovens with a PR department. So they should work almost exactly like an oven except they have a fan blowing the hot air around speeding up the process.
@@pjl22222 Well yeah, all convection ovens are basically the same idea but it's a smaller volume of air and ejects it right out of the machine. More airflow means it'll be able to work its way into the material more efficiently and hold a more even temperature. A good convenction oven works fine but there's definitely a difference and I trust setting aggressive temps with it a lot more than I do with my gas convection oven.
I always did what you were doing and just throwing the little bags into what ever I using to store my filament. I even threw them into resealable vacuum bags not realizing they were probably not doing anything. Time to start drying them first.
I have put a layer of desiccant on the bottom of my filament dryer to act as a buffer, also as an indicator of the humidity inside to see when the filament should be dry enough to use. The only issue is that when the filament dryer is off for an extended period of time, it takes 2 days to fully dry the filament and dryer, so it'd probably be better to refresh the desiccant separately when this happens. I'm in florida, so active drying is a necessity.
I've been using a large food dehydrator that can take 8 filament spools and loads of silica gel packets. When I see 20% humidity in a filament box, I know all the spools and the silica have moisture in them, so I dry them all at once. Once dry, it takes about 6 months before it reaches 20% humidity again.
@@zachgullerman3183 It's a 9-tray Excalibur Food Dehydrator Parallax. I set the temp to 115f / 46c and run it for 10 hours. We originally got it to dehydrate fruit off our trees and make biltong, which it's been brilliant at. Searching online, the price is way higher than I remember it being 10 years ago. I believe they last forever (ours has), so you might find one second-hand.
I have been collecting the large beads and have a dedicated drying device for which I print large vessels out of ASA. Your video is a great explanation full of data and visual cues. Made me to improve my process. Thank you!
Back in the day, i used to advise people to put their video cassettes in a plastic storage container with as many bags of desiccant as they could manage. In a humid climate the binder agent fails and the tapes start to desintegrate.
Excellent video. Thanks for the systematic testing and all the information. It can be overlooked but it is incredible the amount of conflicting information in the Internet about whether or not is safe to use the same oven you use for food for drying desiccant and filament. Here, you explained it really well: you need to use another oven other way there are too many risks.
It seems like it would make sense to throw some desiccant in the hole of the spool when throwing it in a filament dryer to avoid the re-hydration issue.
I use a fan driven dehydrator I bought for exclusively drying filament and silica gel. It heats to a max of 70C but it works great, because it constantly moves dry air over the desiccant. It works great and is fairly low wattage. Also, there is no risk of damaging the gel from heating it too much.
@@yeroca Yup, from start to finish. I've noticed the quite high temperatures when you let it rip for more than 5 minutes. But to quote the comment I saw on another video that intrigued me "I dry everything in the microwave, :) works great and is 20X faster in my experience as well, Have had no issues with overheating (800w) 30-60sec with PETG or PLA" So take what you want from it ¯\_(ツ)_/¯
I use a food dehydrator for both filament and desiccant. They are designed for drying , so it works very well. And they have a temp setting, so getting the correct temp is also easy.
Had a few smaller silica gel packs, put them in my air fryer to dry them out - just to learn that the bag is sealed by glue that melts a bit above 100 degrees C..(boiling point of water, whatever dungree you're used to)... Things take the time things take, so if rushing the evaporation process ... don't do it while the silica is IN the bag(s) ;ø)
I’ve also used the opposite approach by putting silica gel cartridges (not satchels) in the fridge for a few weeks, while it’s much slower the fridge is a low humidity environment and will pull the moisture out of the silica gel by lowering the relative humidity so essentially the same process at different temperatures
Came here to say this. Have a friend who runs maintenance at a cat litter manufacturing faculty and complains about bentonite dust making a mess of things all the time, in particular ruining the paint on his car.
So 10 minutes in the microwave, another half hour in a convection toaster oven. I also like to hit my storage containers with my heat gun, from a distance. You can use other forms of dry air as well. Like a little tiny piece of dry ice. You just need a little one-way vent.
I have been storing bags and bags of desicant and have not yet discharged the moisture from them because I have been unsure of how to best do it. I did one test run and the bag exploded in the microwave, likely due to the extreme change in temperature in such a short time. thank you so much for your efforts in studying the effects of each method you have shown!
Nice to see a technical video after a while. You could have mentioned humidity indicator paper strips which change colour like the beads, but never need to go in the oven. Microwave defrost is usually the second lower power level. As bags, I repack everything using stapled kitchen paper double walled bags. High end microwaves have a DC magnetron and change the power level by changing the voltage supplied to the magnetron. My Panasonic does it.
@@rynait fake strips are very rare if you buy by reputable vendors and in any way it's not difficult to check... They are a practical solution to monitor the air in a container without any risks and without having to change batteries in hygrometers
@@olafmarzocchi6194 Other forum and youtubers says a lot of strips are fake even coming from reputable sources. I only bought a set, for the vacuum bags, set came with strip that did not work. I do not use strips anyway.
@@rynait I have one from Antistat (google "antistat HUMIDITY INDICATOR CARDS") and it matches the hygrometer. 30 pounds per 200 strips, but I got one together with a device
@@rynait I have one from Antistat (search online) and it matches the digital hygrometer. It's sold in 28 pounds per 200 strips. But in general, anything from Farnell/Digikey and so on is reliable. Of course don't go to Amazon or Ali.
One warning about silica gel that isn't covered in this video is that silica dust is extremely hazardous when inhaled. It can significantly increase your chances of developing pulmonary diseases like silicosis, COPD or lung cancer. Many places suggest that an N95 mask is enough to block the particles, but you should also make sure you're working somewhere with good ventilation and wash your hands after directly handling it.
Thanks for making this video, it's exactly what I needed. I've been saving them because I knew they *could* be regenerated, but I hadn't taken the time to look up how. This video answers a lot of questions for me, and I'll be looking for some clay desiccant packets for my cat's dry food feeder, now.
I throw away the silica gel, and use 4A molecular sieves, to dry my filaments. As you saw in the graph, it holds more moisture per gram at very low humidities, and when printing in nylon, I want my filament DRY.
@@CNCKitchen Yup. I have dozens of dedicated boxes in which I keep my filament, to minimize the moisture intake, after removing the spool from the factory packaging. If you're going to use molecular sieves, then you can't store the filament in open air. It's just too much moisture. Upside is that you never have to worry about molecular sieves "giving up" moisture, like silica gel does, when conditions change.
I've collected a few, I knew you were supposed to dry them but just didn't want to blow up the microwave doing it wrong. Glad you made this, I'm off to bung a load in Chef Mike.
Stefan, in museum praxis tons of silica gel is used in storage and exhibition rooms, and it has a well established method for around 50 years, where setting and keeping a certain humidity level that suits the given artifact is key, and since silica gel in large amounts is not cheap keeping it 'alive' is also a factor. Turned out microwaving the silica over and over again -since it's based on inner friction of the heated object and not by convecting heat- it will damage the inner structure of the silica pretty soon resulting the rapid degradation of its absorption capability. So, it's not used in professional praxis. (Personally I don't use microwave for my food either, but that's another topic.)
@@koboglo6973 in old-fashion ovens at around 110°c while the humid air is vented off. Silica is spread over multiple perforated plates in thin layers to expose the largest surface possible, then put in hermetically closed glass containers while still hot.
Consistently useful information supported by detailed analysis. Since I will be moving to a location with 80% indoor RH, I need to take drying a bit more seriously!
Have you tried Activated Alumina? I've been using it since the indicating silica was found to be dangerous. The alumina has been great about keeping my filament in bags and AMS dry and is easy to reactivate in a toaster oven I have in my shop.
Great video Stephan, with your usual thorough testing. I use 2x 20g sachets of Wisedry desiccant in each of my 4L airtight containers. These are colour indicating silica gel sachets. The instructions say to put 5 sachets in the microwave and heat for 3 minutes at 80% power, then turn the sachets over and repeat. It dries them out nicely. The beads return from green to orange, and the sachets weigh exactly 20g after drying. However, I was concerned about the microwave power setting, as the glass turntable gets incredibly hot. Using defrost mode seems like a sensible precaution, but then repeating cycles over and over again sounds like too much hassle. I used to use a fruit drying oven, but it was too big, so I got rid of it. Big Clive's suggestion to consider an air fryer sounds interesting, so I may look into that. Thanks for your great work.
Good to see you testing the beads for absorption after drying, and it's good to see they still work. I bought one of those drying bags from Amazon that hold 300g of silica, the product states it can be 'regenerated' in the microwave, but as far as I'm concerned you have to be extremely careful doing this otherwise the life of the bag is drastically shortened. The MW is a great way of drying fast, but they're almost TOO effective, they heat up too much and destroy the micro-pores inside the silica as the water energetically escapes, makes sense that this should be around 100c. Part of the issue is that stupid semi-pwm method they use in microwaves, as a 300g semi-saturated bag can easily get way past 100c (in areas) in a single ON pulse. Perhaps it's possible to pull apart a MW oven and replace the pwm component with much higher frequency pulses, assuming magnetrons can even be driven this way.
Just after watching this video I tried to dry 200 g of Silica in the MV. Initially on Defrost setting (240 W), but as the pearls started to "Pop", I switched to the "Keep Warm" setting (130W) in 10 minutes intervals. Lost just about 18 g of water in 1 hours time. Thanks for the great tip.
Another technique that would be interesting to see is putting them in a sealed container and drawing a vacuum on it. There are custom-toy hobbyists that have cheap vacuum chambers for removing bubbles from resin molds, so having the means to do so isn't unreasonable. The moisture in the gel should then boil off at room temperature, removing the risk of melting anything, at the rate of however long it takes the air compressor to draw a vacuum each cycle.
The low air pressure will also affect the relative humidity, tho. Boiling off even a little bit of water will significantly raise the relative air humidity, so you'd probably need many, many runs.
@@marcus3d you could easily break the vacuum by releasing a small amount of air. The significantly higher concentrations of nitrogen and oxygen would displace the high RH low pressure atmosphere.
@@mattpatt The smaller the amount of air, the more often you need to replace it because it hits high RH. Even at sea level pressure the air will need to be replaced quite often, and if you remove half of the air that doubles the number of replacements needed. You're gonna be running that compressor a lot, I think.
@@marcus3d is RH an important factor though? As the absolute pressure reduces then I imagine the driving force for adsoption reduces too. I guess the silica gel adsorbs water selectively but in a normal air mix the partial pressure of water is low. In the vacuum you describe the RH is high and so the contribution of water to the absolute pressure is high but I imagine it wouldnt take much vacuum to significantly reduce partial pressure of water. Unfortunately I'm not an expert in this and can kind of guess but not be certain. I do know from experience that when vacuuming refrigeration systems it is common to draw a deep vacuum and break with nitrogen only 3 times and that is considered good enough to "fully remove" water. To the extent the goal is
@@mattpatt RH is the key metric. It describes how saturated the air is. When the RH of the air equals the RH of the filament the transfer of water stops. I don't know about removing water in refrigerator compressor systems, but normally the compressor is in refrigeration just to change the temperature back and forth, so that we get 2 different temperature differences, to enable the transfer of heat in 2 different temperature environments. (One colder, one warmer.)
All the things I always wanted to know but never got triggered enough for to actually go after it and figure it out. Thankfully you did :) As with lots of things. Thanks, great video again!
When I had easy access to cryo-equipment I used to freeze dry silica gel (and fruit slices). I don't think it was particularly energy efficient (and tended to fill up the moisture trap in a hurry when I added to the collection). But I wonder if hanging the heated bags to dry in an ordinary freezer (so that most of the heat/nrg exchange is by convection/evaporation rather than conduction) would have a measurable effect. (edit; 19min, 1 like later:) -oo- if suspended in a container/jar (w/ thread), then we'd get to see the water/whatever that was still in the bags/packets freeze to the walls, (edit 2:) and not worry about condensation affecting them. ( I might try that with some of the packs from my prescriptions, since they're explicitly only supposed to be "used" for {3 months, or 50 open/close cycles} without recharging. ) (edit 3, 27 min later:) Wait -- Why haven't I just been using a 'vacuum' bottle and the freezer/winter to dry them? I just need to figure out where the pump got to... )
He tested using a vacuum pump on filament a while back, and for some reason that I don't really understand, it wasn't as effective as using hot air, though it did reduce the moisture content to some degree.
*Bentonite is basically cat litter.* I see a great opportunity for recycling used cat litter here: *ahhh, I love the smell of microwaved cat turds in the morning!*
I live in a dry state i never thought my silica packs would get much moisture, after watching this i thought i would try my sunlu with the Turbo Mod to at least check. Was i ever wrong, they obviously had lots of moisture. Thank you for posting this informative video.
I recall people using round food dehydrators for filament drying a couple of years back. I accept that this really only works as long as you move the dry filament into a moisture tight container immediately after drying. What I was wondering about, and don't really see it mentioned other than possibly as related to the Creality filament dryer, was if one kept a dry tray intact, and spread out the filament bags on it, would that give useful desiccant drying as well. I imagine that it would need a longer cycle time, but depending on the heating mechanism time, that may not be an issue. I would imagine one would still want to drop the resulting desiccant into some variety of dry box to keep it dry.
I bake and reuse these all the time. I've learned that what really matters is the sachet, not the desiccant media. Some bags are made of an expanded PTFE that shrinks and becomes impermeable if you bake it in an oven; they're designed to be dehydrated in a vacuum oven. Others are just paper. Today I have a big tray of calcium chloride in a fish tank. I put the desiccant bags in the fish tank and the CaCl sucks the water out of them slowly over time without heat. I bake the CaCl dry when the tray fills with water.
Great video, thanks. An Air fryer might be the thing to use. It has the control but uses hot air blown over the stuff so should be fast. They are also said to be more energy efficient than a microwave. Also I do not have an oven.
Great work Stefan… your videos are greatly appreciated… great information, very useful, consistently and systematically demonstrated with well crafted and precise tests and measurements…
THANK YOU I've had dozens of users ask me if they can use my SPILLPROOF ams desiccant boxes in the microwave, I always tell them I've not tried it and wouldn't because the beads can get extremely hot and melt the container, now I know for sure, over 100C is crazy! Definitely would melt PLA and PETG THANK YOU
Thank you, Stephan. This really lit up my lantern. I used to do the same thing; I will dehydrate them before using them in the future. Merci Stephan, cela m'a vraiment éclairé. Je faisais la même chose, je vais les déshydrater avant de les utiliser à l'avenir.
I once had a wheelbarrow full of 1kg bags of silica gel. They were shipped (or rather LKW'd) with a Trumpf TruBend metal bending brake (Abkantpresse) to protect the machine from rust.
I recently purchased some filament dryers, when I had dried the filament by itself for quite some time but I figured I would throw in a a few silica gel packs to preserve the low moisture. I came back to find the moisture level inside the filament dryer had risen and there was even a bunch of condensation I had to wipe off. My conclusion was that the silica had picked up a lot of moisture in transit I when I heated it up it was releasing it back into my filament.
Drywall, gypsum, is a hydrate of calcium sulphate, it has a bunch of water embedded in it. One can dry it out in the oven at about 230f 110c. It will work as a cheap desicant in bulk that can be easilly recharged over and over. But, using too much heat will still dehydrate the calcium sulphate but the crystals will change to a form that doesn't absorbe moisture well and it won't work as a desicant anymore. But, that is avoidable by not heating over 230f oe 110c.
Another method I found very effective is putting the bags in a vacuum container, like the containers and vacuum pumps used for degassing resins in composite manufacturing. Very effective and no heating that can damage the material or the enveloppe.
I dry my desiccant bags in the microwave on high for 30 seconds then let them on a small fan cool for a few minutes. Then I bump the time up to 40 seconds, let them cool. Repeat until the bag feels dry when you take it out (or for about 4-5 cycles). The clay type desiccant can't handle this method and will melt the bag. This method is probably faster than the defrost power method you describe. Great video!
I’ve been collecting filamenr desiccant bags for years. I've dried my bulk silica beads in the microwave and have been happy with how well it works. The bags I’ve been collecting in part are in a big bag and being used to counterbalance the boom arm for one of the studio lights. Repurpose is sort of like reuse, right?
I collect these too. I learned to recharge them many years ago. I recharge with a toaster oven. As cool as it is that it is possible to recharge with a microwave, I won't be doing that. Microwaving anything without sufficient moisture present can damage the microwave. While it's probably safe to microwave as little as half a cup of fully saturated desiccant, the more moisture you remove, the more likely it is to start causing damage to the microwave. That said, I do want to insulate my toaster oven really well, because those things typically have no insulation and just waste heat like crazy. Given your experimental numbers, it probably wouldn't be too hard to insulate a toaster oven enough to have efficiency levels close to that of the microwave. (Maybe better, as microwaves also leak heat pretty fast, when run for long periods of time.) I mainly use my silica gel desiccant for its intended purpose. I don't keep clay desiccants. I'm not super concerned about the environmental factors, and silica gel is superior. That said, some clay "desiccant" packets are not actually desiccant. They do have some desiccant properties, but certain prepared clays also absorb other elements, including heavy metals. These are often what the clay beads are, and they are similar to the clay beads used in water softeners. They can be recharged with salt water (I forget the process, and you may need a specific salt, like the calcium chloride used in some water softeners). The only use I've found for these is adding to garden soil. I don't bother trying to recharge them, as they are very unlikely to have been fully exposed and saturated, and some of the things they can absorb are actually good to leave in them for your plants. They can also filter out and bind some things that are toxic to plants. I'm not sure a packet now and then is enough to make a difference, but at least the material is being recycled in a useful way instead of being tossed in a landfill where it will be generations before it can provide much value. Anyhow, I recently discovered something: Silica gel can be used to make high purity water glass. Water glass, aka sodium silicate, is a substance that has very good thermal properties, is water soluble, and dries to a glass-like transparency (supposedly; I haven't made any yet). Technically you can make it with silica sand, but sand typically has a ton of impurities. When used in refractory materials, it can act as a binder or even an adhesive when dry, and with sufficient heating the sodium will separate from the silica, removing the water solubility and producing an even better refractory with good structural properties. Anyhow, to make water glass with silica gel, you just react silica gel with sodium lye (often sold as drain cleaner crystals) in a solution of water. The lye will dissolve the silica gel making sodium silicate, which can then be added to a firebrick recipe or (according to someone else on RUclips) mixed with garden lime to make a very strong refractory adhesive. I'm currently working on building a new smelter and forge, and this time I'm going to use water glass in the mixture, in hopes that the structural benefits will allow me to use more perlite and vermiculite for even better insulating properties than past ones I've made. And I'm going to use the lime/water glass adhesive to coat the inside of both of them for improved structural integrity. Wish me luck! But yeah, that's how I'm using my silica gel! (I have plenty, so I'm only need to use a small amount of what I have for this project.)
While working at a PC components company in the 90's I collected about 400 fabric bags. I emptied them and dried them in a gas oven and used them to really really dry things. A dead frog was the most memorable - it weighed almost nothing and was surprisingly strong - it lasted for years too without rutting. Oh, and regularly stirring/rotating the beads while they cook releases a lot more steam. It's as if the top layer traps the steam inside but it was a large metal bucket full.
Thank you for the video, I was planning to do similar tests but you did it first, you saved me a lot of work !! Also, I know the point of your video was to reuse dessicant from spool bags, but you can also buy large amount of silica gel in most supermarkets in the form of...cat litter ! Indeed there's a lot of different litters for cats, and some of them are just large and cheap bags of silica gel (it's usually written on the bag). The only drawback is that it's actually bad as litter for cats (silica gel bits are very hard and sometimes sharp and can damage their paws...) so buying it kind of support a bad product, but it's hard to find cheaper than that !
Another major tip. It's extremely hard on a microwave to run it dry, they tell you to put in a cup of water if you're microwaving a taco shell or some other mostly dry item. Put a small amount of water in a bag, then inside another bag or two. That way it won't leak out if some leaks, coverts to steam, etc. Yes it will split off some of the energy, but it gives an OK target, and any steam will stay in the bags instead of having an open cup.
On the point of not expecting or thinking about using a microwave for drying. I know a fellow who's good with electronics was asked to see if he could repair an industrial lumber drying kiln. It turns out the kilns used for making lumber are basically just massive microwave ovens. You can basically walk around it and look at the circuit components because of the size needed for capacitors and resistors in something that works at those wattages. At the end of the day he found a capacitor about the size of my head that was blown.
I'm also kind of curious now. If we outfitted your custom toaster oven that has the thermal couples in it. With a humidity sensor and a fan and had the fan kick in when humidity reached a certain saturation could we improve the functionality and cure time of the toaster oven by evacuating the humid air on interval..
I used the blue/pink silica. I dry them together inside my spools on a terrarium heating pads with a card box with a few small holes( the card box where the rolls are shipped in) on top. It works great and is very cheap.They get a very deep blue color. I only rotate the spools a few times. I store my spools with the silica inside them using vacuum food sealers. I make the bags a bit bigger so I can easy reuse them without wasting a lot of plastic when cutting them open again. Before that I used those Chinese vacuum bags with valve but found they where one time use only, so that was a waste of money.
@@javan6982 I use 15W pads that cover the spool, they can be regulated. I don't have a thermometer. So I can't really tell the temperature. If I have to guess by touch I would say around 50 degrees. they feels pretty hot.
Я собираю пакетики с силикагелем и периодически сушу его в микроволновке. Мне понравился ваш способ сушки материала в вакуумной камере на столе принтера в предыдущем выпуске. Мне этот способ помог высушить нейлон, который никак не мог высушить в духовом шкафу в течении 3 суток при 90 градусов. Материал очень сильно не хотел отдавать влагу, но я благодаря вам его победил. Спасибо! (I collect bags of silica gel and periodically dry it in the microwave. I liked your method of vacuum drying the material on the printer's table in the previous issue. This method helped me to dry nylon, which could not dry in the oven for 3 days at 90 degrees. The material was very reluctant to give up moisture, but thanks to you I beat it. Thank you!)
I've usually used the microwave method to rejuvenate sachets, along with some kitchen towel underneath to absorb sweating on the base. Like Stefan, I've found a traditional oven gives the best result, but microwave does work well. Just a few beads of the toxic orange colour indicating ones, much fewer than Stefan had, is sufficient in a mix of white untainted beads to judge whether it's time to recharge them.
The efficiency of the microwave makes perfect sense. Its a bit like induction heating since a microwave really efficiently heats up water, so it heats up the filament by heating the water that you are trying to remove!
I just use calcium chloride, which absorbs 7 times the amount of water than silica beads, and is way cheaper. My drybox generally has a relative humidity of 7%. The only drawback is that it turns into a liquid when wet so just put it at the bottom of a bucket and seperate it from the filament with a divider. You can bake it in the oven as well. Maybe next video idea? I've obserbed that if I put in a very wet TPU or PVA that is even slightly mushy, it dries it fully in a week or two if it is terrible. So no dryer needed. I live in a place with generally 70 to 90% RH.
As a thirty something guy i was planning on using my air fryer on dehydrating mode, 80c but with constant hot air flow. Was hoping to see an air fryer here!
Wait so are we eating them or not?
Absolutely!!
Why else would they say donut eat on em
@@SupaaMann 😂 😂 😂
I always put them in my drinks. How would you else make a gin dry?
Silicagel is not reactive, you just get very very thirsty
I'm glad you covered this because so many people think these are little bags of magic that keep sucking up moisture forever and never release ot back.
Indeed, the dirt isn't magic.
I admit that I never really thought about it and just mindlessly reused them. Seems really dumb in retrospect.
@@chrisl4999 it can be hard to think about because with the little packets there is no obvious change if they are dry or wet (other than weight but the change is too small and gradual for most people to notice). Something that is much easier to visualise is dehumidifiers, both the since use ones and electric ones. The single use ones for use in cupboards and closets and similar typically have an area of desiccant and a tank for liquid underneath. Over time the desiccant disappears and the tank fills up, I don’t know what desiccant they use though. Electric dehumidifiers work different and don’t use desiccant but you can see just how much moisture they pull out of the air. It is very surprising how much they can pull out that quickly.
It's very funny to observe chinese worker's action who"s getting SG bags out of the big uncovered basket stayed here for several days at almost 100% relative humiduty of the air of the South China, and putting it to the sealed packaging together with the product.
That and activated carbon filter things.
urgent safety warning, since you missed it
some desiccant is based on calcium chloride, like the packs Bambu Lab sells for their AMS
calcium chloride is very potent in chemically binding water, it is not just absorbing it
it theoretically can be regenerated, but when you heat it too fast, it will decompose partially into hydrochloric acid
the temperature window is quite small, so absolutely do not do this at home, you don't want to inhale hydrochloric acid fumes
how does it look? it is usually a white-ish powder, like powdered sugar or flour and when saturated it turns a bit yellowish, sometimes it also looks porous like the kitty litter stuff - you can buy those in large quantity for passive dehumidifiers
but you absolutely need to discard those after use
Good to know. I've "successfully" regenerated damp-rid in a stainless steel pot on a hot plate indoors twice, but at the time didn't know why the "odor" it gave off made it hard to breathe. I didn't get any long term ill effects from doing it, and I also smoke like a chimney. I suspect of all the acidic gasses a person can inhale, hydrogen chloride is probably not terrible in low concentrations, because that's also what stomach acid is. It makes sense the body can handle it in the wrong places in small amounts. I'm not recommending doing it though.
Inhaling HFl is relatively worse. A decade ago I was cleaning mineral build up off of a pair of storm windows and had the bright idea to lay the windows flat and cover them in Wink cleaner (nothing else was working). In hindsight I'm not sure how I survived inhaling HFl fumes for half an hour as I was leaning over those windows scrubbing them. It did do a great job of cleaning the glass, but it was also probably etching it slightly and definitely burning my lungs. I'm sure breathing acid isn't the dumbest thing I've ever done, and it happens to a lot of other people who don't figure out it's bad and keep doing it until it messes them up.
@@chrisbalfour466 the fumes won't kill you and it probably won't have any long term negative effects, but still you don't want to inhale it if you don't need to
lots of household chemicals include hydrochloric acid, like cement stain remover for example - it is just nasty
yeah, dont eat those ones!
@@JasonBlack66 Oh I don't know about going THAT far. A little hot sauce helps.
@@suit1337 "t probably won't have any long term negative effects" except the iron/steel (e.g. pliers, cast iron pots/black steel pans, things like this) may start to rust a lot faster even from the air moisture. Ferous chloride is hygroscopic and the chlorine ions act as a catalyst for the rusting process.
I've been drying silica packets in the microwave for a while now and I'd like to share a couple of tips.
1/ After you thoroughly dry a sachet for the first time weigh it and write that on it with a marker, then later you can easily find out if it needs a refresh by how much weight it has gained. If you have kitchen scales this only really works for larger packs (25g+), for smaller packs you need more sensitive scales. This also helps with the drying process as you can sse how it's going by measuring in between cycles in the microwave
2/ Put a paper towel under the sachets in the microwave, it will significanly reduce the chance of melting the bag vs putting them straight on the glass turntable.
3/ Give the sachets a good shake in between cycles in the microwave, particularly the first couple, it helps get the steam/moisture out through the bag.
Writing the dry (minimum) weight on the bag is indeed a great idea.
I am surprised this works. We dry silica with heat at the lab (electric drying furnace at 100C/212F for 24h), so drying it in a gas oven was impractical, plus the risk of flames.
I thought microwaves could be too intense and would cause the beads to pop, making it much less effective by absorbing humidity too fast (simply taking it out of the microwave would render it useless).
I guess it works!
Coffee scales are good for weighing these quantities
Good tips. Those tiny $10 digital scales are all really good. I've been using them for years. Compared with my sensitive gram scales in my science classroom, they were within 1%.
I might be responsible for spreading the 'rice thing.' In 2000 I was hiking in Yunnan China and got wet in stream at Tiger Leaping Gorge. The felt light block on the film cassette was wet. So back at Tina's (still there) I asked for some dry rice. I knew that uncooked rice is hydroscopic. I packed the film in this in a canister until I got home in the states. Then chatting with friends in our online group the subject of wet electronics came up, so I shared the tip. (I can't be the first because it's so obvious.) We decided that a vacuum with heat would be good, and that in a pinch uncooked rice might help.... So I wrote it up and shared it around the internet.
15 years later I went into the AT&T store said I dropped my phone in the ocean and... the clerk interrupted me telling me the rice method. I swear it was almost verbatim what I'd written. But that can't be possible..... Later when I switched to another carrier I asked about what to do if a phone got wet.... This clerk told me about the rice, but it was more general. So maybe.... Then Louis Rossmore who complains endlessly and occasionally fixes laptops had an entire episode haranguing how stupid the rice method was.... I think I turned it off when he was shouting that dried rice won't cure herpes.... But rice is basically similar to these products in this video. So where they work, rice would work.
Searching the internet I've found some links that say rice isn't as good as silica gel and some that say it is. The big difference my friends back in the old millennium decided was, you wouldn't use rice because being edible it would attract vermin (rats like dry rice).
I think an ideal method would be to 1. figure out how to safely use your microwave. 2. figure out a way to remove the humidity in the microwave. I might try putting heated desiccant bags in a vacuum bag and run the cycle of my vacuum sealer (You could also use a zip lock bag by cutting off the sealing strips and turning them sideways to make a gap to suck out all the air.
3. Set up a schedule. Write on the bags the weight (great tip! thanks) but also a date, and then put a schedule in your schedule App. (I've been terrible with my lithium batteries not using a camera for many months and killing the battery.) Then weight them or just run them through the drying cycle. Weighing them you might decide the time between drying can be extended. But if you just do this every couple of months, or have a supply of extra bags on hand... it should be easy.
How much precision do you need for the smaller packs? 0.1g ? 0.01g ?
Panasonic microwaves use inverters instead of transformers and can actually output a percentage of the power vs full power on/off. I think there are now other manufacturers who use inverters, but it's good to know that they're out there and work significantly better than transformer-based microwaves for less-than-100% output, which generally works a lot better for heating food more evenly. I imagine it would work better for regenerating desiccant as well.
Love my Panasonic microwave with inverter. Best microwave we've ever owned. It's sensing feature for heating food is really good also. It's what I use it for the most, reheating.
Here's More Panasonic love and encouragement to try a drying test. With an outlet store discount and an eBay discount, it still wasn't cheap, but it's a combi, and I use it almost every day, so it was worth it!
As a combi oven, it raises the question of a drying test with microwaves, temperature-controlled oven and even grill?
Good to know. I had wondered if there was some minimum voltage required to drive the microwave gun, which was why it is only on or off.
Im so glad it isnt just me that loves my Panasonic combi microwave. Best appliance we own. It's not even close.
Funny to think that what an inverter does is switch the power supply on and off to give an average that is less than full power.... exactly what traditional microwaves are doing with the microwave gun. Just inverters do it in the kHz or mhz range. Exactly the same technique, just faster.
I used to work on a satellite uplink/downlink dish that used rectangular waveguides that were kept slightly pressurized to prevent moisture from collecting in it. The intake to the air pump had a bottle of blue indicating silica gel. As part of the scheduled preventative maintenance we'd swap out the beads and then microwave them until they turned blue again, and store it in a screw-top jar until next time.
It’s fascinating hearing from all these comments how common it is to use a microwave to regenerate silica gel in professional industries.
There is a way easier way to judge if the gel or clay is saturated or not. Just throw it into an oven at 110 degrees until they are heated and then hold them against a cold surface like a mirror or window. If the window shows signs of condensation, they are wet. If not they are dry. I have a couple of 1 kg clay bags that I throw into the oven every now and then overnight and when they stop causing condensation on the mirror, they are dry. Thats it, back into the box with the filaments. 2 kg of clay is sufficient to keep the filament dry for a couple of months to a year.
And if the window shatters you overheated the desecant. Perfect
I simply weigh the bag. I know the weight when it's dry, it's about 1kg in my case. I used these to get the moisture out of the car. The weight has gone up to 1.4kg.
110 Celsius or Fahrenheit?
@@torquebiker9959 That's incredible, almost half a litre of water absorbed.
@@roterex9115 lol 🙈
my theory on the microwave being so effective is that it's because of how microwaves heat things. They literally heat the water molecules, and in this case, boiling off the water is exactly what we're trying to accomplish. All the other methods are radiative/conductive heat which has to heat the entire mass up to the boiling point of water (or whatever the temperature that the desiccant releases water at) in order to get rid of it, whereas the microwave selectively targets the water just by being a microwave.
@@bepstein111 Of course but it's also the downside because microwaves don't necessarily heat everything in them evenly, especially the cheap ones we'd likely use for this. That leads to hot spots and likely why he always heard some cracking. That's not to say it isn't useful but I'm not a fan of using it for larger quantities if dessicant.
I'd be curious to see someone put together a design out of old microwave parts that's meant specifically for dessicant (or even filament drying)..
It's a myth microwaves only heat water. They will hear anything with a dipole moment. Such as fats and oils. Or in this video, clay that probably had some iron contamination.
I think it might be worth mentioning: Don't disassemble a microwave if you aren't *very* familiar with how they work. They have a very large capacitor and can keep a lethal amount of electricity for a surprisingly long time.
Attempting to make a desiccant re-furbisher while on the wrong side of the Dunning-Kruger effect has an extremely high chance of being the last project you work on.
@@Sylfa Yes it's easy to forget that someone might actually attempt a shower thought comment. While I'd hope anyone who'd even think about such a niche project knows how to discharge a cap, screwing with microwaves is a whole other can of worms. I work with electronics for a living and aren't afraid to admit that doing this safely is well outside my wheelhouse.
@@JJFX- I figure the risk of someone seeing it and actually doing it was minimal, but like with Lichtenberg wood burning disassembling microwaves falls into things that keeps cropping up in various contexts and hobbyists completely fail to see the risks involved.
Nice thorough bit of testing. I've been using my microwave to dry bulk silica gel, but at full power, which may not be great for the gel or the microwave itself. The defrost mode is a good idea. I also recently got a cheap air fryer to test as a dedicated dryer, making sure it never gets contaminated with oils from previous food use.
It makes sense to me to use more power for bigger batches. Besides, it's just silica in a funny shape. What's the worst that could happen to it?
I tried that with cat litter silica and the fan just blew the silica around the fryer.
I´d personally use the food dehydrator with stackable plates. That might work well. Anyway, I did the exact same thing with microwave and the beads just cracked and exploded because the microscopic pores well suddenly full of steam.
Clive from Isle of Man, you are da Man! Please post the air fryer results on your channel as I am subbed there.
Nice to see you making the rounds...
Thanks! I recently figured this out - that my desiccant was adding moisture to filament that I had just removed from the dryer. Your advice on how to dry the used desiccant will be very helpful and I will put it to use immediately!
Yeah I already eat them
Yummers.
I use them in dry martinis.
@@R.Daneel Cheers! 😂
So tasty, and 0 calories!
No worries, you can collect them next morning!
Hello.
I would like to add some information to the test, especially since I personally use 1 kg silica gel dessicant bag for my car (reusable):
-In large quantities (like 1 kg) you can genuinely blast silica at full power bursts for 2-5 minutes, because the energy is more dispersed, and therefore power density is lower.
-There are large reusable silica dessicant bags (1kg) available as "car dehimidifier", they even have heat-proof indicator that mostly works (Limpro for example)
-You do not need to heat the silica so much - even temperature above 50-60°C will start pushing the moisture out.
I recommend:
Buying 1 kg reusable bags for cars (indicator not necessary)
Drying in microwave on full power for less than 3-4 minutes each time
Place it in microwave on some kind of rack made of cardboard or similar, so that the bag gets better air flow
1 kg of silica in my case contains ~200-250g of water after full use, so it will take a while to remove all of it - 3-5 cycles with long breaks inbetween.
P.S. 1kg dehumidifier should cost as little as 5€.
I would recommend bags of "crystal" cat litter box material.
Its a cheap way to get hold of large quantities of silica gel locally
Just don't ever get the idea that you can refurbish that type of cat litter when used for its original purpose. You might just void your lease.
The smell of boiled cat pee is a small price to pay for saving a few cents. Just remember to get the worst chunks of the forbidden play-dough out 😩👌
It's not crystal, it's also silicagel. I've tossed some in my passive dryboxes and it seems to work fine though the overall moisture level in my apartment is just high.
@@Sylfakitty litter is so damn cheap, you won't even bother to think about refurbishing it, even in your final thoughts.
@@thethingsido4051 Certain types are (clay especially), other types aren't as cheap.
Stefan, there is another option for testing the moisture levels in your desiccant that I use in my lab to check if my cement sand is microwave dried. Take a strip of plain paper, approximately 8 cm in length by 2 cm wide. Place it on top of your desiccant. If the paper starts to curl at the ends, it still has moisture. The humidity will warp the paper. It's a small trick, low tech, but it works very well.
Wow! This is super helpful. To be fair it is CNC Kitchen is one of the keys to me having success 3D Printing. Thank you again Stephan for upgrading my 3D prints.
Agreed my 3d printing would be way behind where it is without this channel.
Thanks so much! I’ve been buying bulk 100% silica gel kitty litter and drying it in the oven. I fill up an old cotton sock and use that as my desiccant pack. Going forward, I’ll be using the microwave to dry the silica in a much shorter time.
I work on large electronics and often get 200g desiccant bags. I throw them in a box and once I get a nice supply I dry them out in the oven per the MIL-D-3464 spec of 245f for 16 hours. After that I use them in my tool boxes to keep rust away and in my filament dry boxes in lieu of buying new.
Quick edit: I was an Aircraft Mechanic in the Air Force, we actually used the microwave method to quickly dry out the desiccant used for one of the avionics unit on board.
Those big bags are great for storing marine electronics like hand held VHF. After a kayaking trip rinse the set with corrosion inhibitor and seal into a lever lock box.
WiseDry always give you the pack weight so you can check weigh moisture content. My tip is BUY NEW SACHETS. They are cheap enough. Being a cheap skate is dumb. This content creator seems to feel cheated because the sachet has already done its job when he opens the bag of filament but he is too mean to toss it away - - like it says to do on the packet !!
@@causewaykayak Some of us just hate being wasteful sods :)
@@3nertia That's nice 👍🏼
@@causewaykayak Nice indeed 🙄
Our Tax Dollars at work
I solved this problem by living in a desert. Ten percent relative humidity for 90% of the year makes it pretty easy to keep things dry. I would add something like paper towels to the microwave to help soak up the moisture you're vaporizing out of the desiccant.
The desert is not always the best solution. I'm in Scottsdale, and today its 48% outside. Even when its 10% it often is much higher inside. 35% typical in my house, and in in the winter I add a humidifier so it raises to maybe 45%. Much too high for filament. True, its not Florida, or Texas.
@@A1N0 Of course the humidity will be increased when it rains in the area, but most of the year it is 10%. My house isn't any more humid nor is my garage. If you're maintaining that much humidity in your house when it's 10% outside, you likely are cooling with a swamp cooler. An AC isn't a dehumidifier, but it does help pull humidity out of the air.
@@fokker1138 A/C is literally a dehumidifier - that's how it pulls heat from the air, by pulling the moisture and thus the heat out of it lol
@@3nertia It's literally not a dehumidifier. It is specifically designed to cool air and just pulls some moisture out of the air due to the cooling effect. A dehumidifier is specifically designed to pull moisture out of the air.
@@fokker1138 What a coincidence because a dehumidifier and air conditioner contain the exact same components operating the exact same way lmfao
It's almost as if someone made a "dehumidifier" and then they realized it had an "evaporative cooling" effect that could be utilized as an "air conditioner" ....
I've always just chucked them into my dry box too and wondered if I was doing more wrong than right. This video is perfect for me :)
Ahh finally an episode in the kitchen!
I have been drying my descant in the microwave oven for years, it is really fast. However, a solution to not having it "over cook" the desiccant (ie melt plastic bags) is to just add more desiccant. As in a lot more. As long as one can spread it out as a suitably "thin" (an inch is adequate) layer it is fine, and the wonderful wire rack one gets with some microwave ovens meant for having two plates in the oven at once is a great way to double the amount of available area without hindering the microwave's ability to heat everything "evenly".
Simply stated, the microwaves are going to dump all their energy wherever available, where the most RF absorbent material takes the most of the available energy, luckily enough that is most often water. So give it more desiccant to spread the energy into. Downside is that it won't dry your desiccant as quickly, but given the fact that it is already practically "instant" compared to other methods, this isn't really much of a downside.
Another method is to babysit the oven and manually pulse it between on and off if one has too little desiccant. After all, you don't want too much heat.
However. Heating it in an oven is far easier to not overheat it. An oven set to 110 C won't magically get to 150+ C, unlike the microwave oven that just dumps X watts into its interior almost regardless of internal temperatures. (though if there is too little in there to absorb the RF energy, the magnetron will usually heat up instead until its thermal fuse saves the day.)
I’ve been collecting my silica gel packets, storing them in a small plastic box. Good to know I will need to regenerate them before using. Thank you!
One thing to keep in mind with a microwave is to be very careful to do it as slowly as possible. Setting the microwave to the lowest setting is the best way because microwave ovens from different manufactures operate differently on defrost. Some on a defrost setting will at first kick the power up a bit for the first couple of minutes, then slowly decrease it. This is the opposite of what we want, because heating silica too quickly, while saturated, allows the water to boil inside the Silica Gel bead and with the massive expansion of the steam, can't escape the microscopic "holes" in them fast enough and they will crack and split, damaging them and making them far less effective.
Indeed. I’m not sure why people are recommending the defrost setting when most microwaves have a literal power level setting, which is a much more direct and reliable way of achieving what we want: low power. (Unless the power level setting isn’t actually as common on microwaves as I’m imagining?)
Why would breaking the silica into smaller pieces make them less effective?
I'd think the opposite, as the smaller pieces would make the escape path for the water shorter.
@@nlkatz Here is the theory: Silica gel is made of silicon dioxide and is highly porous, with millions of tiny pores that can capture and hold moisture. Water molecules are drawn into the pores by capillary action, and then held there until released. If these pores or capillaries are made larger by chipping from rapid expansion by steam, they are no longer small enough to absorb and hold the water. You are right though. Smaller pieces can absorb quicker since they have more surface area exposed. But the breaking is more at the microscopic pores level and is where the problem is. On a related topic, I think the benefit of small beads versus larger ones also depends on air flow. Larger beads allow more air to flow around them and may work better where there is little airflow. If you have lots of airflow, the smaller beads definitely will work better. I tested this in a container filled with Silica Gel using forced air. The smaller beads worked way quicker. But without the forced air, the bigger beads worked quicker. If there was interest, I'd do a video on my sealed filament cabinet with a forced air silica gel based dryer. I even have an app that tracks the humidity and can regulate it at a specific percentage by turning the fan on/off using a "humidistat" (made with a BMSE680 and Arduino) . When the Silica is fresh the fan only runs very periodically, but as it becomes closer to saturation the fan rate increases to maintain a steady humidity level. Fun stuff...
@@triadxtechnologies That theory doesn't hold water.
Literally; capillary action works only with liquids, and we're dealing with vapor; I believe the correct term for what's happening here is adsorption.
I agree that at some point breaking into too many pieces will reduce the number of pores available to capture the vapor.
@@nlkatz You are absolutely right. Adsorption is the dominant force taking place.
While capillary action helps draw water into the pores, the primary mechanism at play is capillary condensation. This occurs when the vapor pressure of water within the pores is higher than the surrounding environment, leading to condensation of water vapor into liquid water within the pores. Alongside capillary condensation, adsorption is the dominant force.
Anyhow, the point I was making is by heating too fast can damage its porous structure.
Thanks for making such detailed experiments : )
Dunno if I missed it in the video, but I gather the silica gel pores start to close over about 90 deg C. At around 18:30 I saw the silica hit 130 deg C in the microwave which I think would largely destroy its ability to collect moisture because all the pores will close. I think the microwave is probably excellentwith the right method. The brisket bbq people have the right idea "low and slow". I am personally fascinated by the way a refrigerator and freezer dry things out. It might be an equally useful method to dry the silica without risk of thermal degradation.
I've been collecting them for a few years, but never considered drying them out. Thanks for the video today, it was helpful and informative.
Really? What did you think it did with the moisture that was absorbed?
the colored silica beads are orange and blueberry flavours, I cook them in the oven after making chicken and they make a wonderful dessert
Ha, ha, ha.
The definition of dry humour
That culinary suggestion sounds to die for.
Thanks for this. I have been using the bags without drying them first. No more! I also have been using Eibos plastic bags for storage that have a threaded opening where air can be evacuated. I then made a part that attaches to my vacuum cleaner to create the vacuum inside the bag. Now with this knowledge, the bags will keep dryer.
There is one more method that might work for you: vacuum+heat. This is widely used in the drying of exotic high-value timber and is able to bring saturated wood down to 10-15% moisture in rather quckly without inducing stresses (if done properly of course). Vacuum kilns are not exactly common, being quite expensive to set up, but they are probably the most effective way of quickly drying fresh timber which is basically a big water-soaked sponge.
Yes. Are you know it is dry when the vacuum holds up.
I was going to suggest this myself. I haven't tried it yet, but in theory, nearly 100% of the water content could be removed from the descant in a vacuum at room temperature. It would probably also be the most energy efficient method for removing moisture. At a modest vacuum of 5% atmospheric pressure, all of the water should "boil" out of the desiccant over a short period of time. The maximum dryness would be indicated when the static pressure of the vacuum container stopped rising (when not actively pumping), and of course the weight of the container could be monitored as well.
Glad you told people not to do it on full power because I tried that before, thought it would speed things up - and it overheats the granules and cracks them.
Aww you cut the bag when it was resealable!
In his defense it was very satisfying
Go away.
I think he did it on purpose to irritate us!
😭😭😭😭😭😭
I have bags that have special valves for vacuuming them. In spite of being adhesive based, it's remarkably effective. I had a spool of PETG that was still almost too vaccumed after sitting on a shelf for over a year. The bags that come with filament don't have this feature.
Just the video I needed right know. I am in a whole rebuilding process of my 3D printer and workflow and would like to print materials which are need to be stored dry. So I was thinking of how reliable are the reused gels etc. Basically which you covered all. These measurements and tests are so valuable for the community and you do win us time and money with this work. So I wish you great success in the future and thank you!
I worked at hardware stores and they literally toss out these baggies nearly every night. Pounds and pounds of them. So I asked if I could just take them with me, and they said sure - since they were just trash they were paying to haul off. Now I have like 5lbs of the stuff to work with, for free.
I have been using a little toaster oven but I think I might hit them with microwave first, then some toaster time before going into a sealed container until use. Benefits from both, the quick 5 minute defrost time- then bop em in the oven for a while and let slow release the rest.
not applicable to me but the ammount of work done in this video deserves a like.
The most useful video I’ve seen in ages. Thank you!
Great to hear!
After trying a lot of options I've settled on using a cheap air fryer. Microwaves work great but it's hard not to get hot spots and damage them. The air fryer at lower temps not only dries it faster than an oven but it evacuates the air out the back which you could probably use to measure how much moisture is coming out. I use an aluminum baking tray that I punched a bunch of holes in with a thumb tack to let the air pass through and you could optimize this further for drying a thick layer of dessicant.
Back in the day I had a combo toaster that used low power microwaves and heat to cook faster which would be really interesting to try but this concept seems uncommon now for some reason.
I just dried mine in an air fryer and my fancy air fryer can only run for 1hr max but it has a dehydrator setting that can run for 8hrs which would be total overkill for desiccant but works for filament spools.
@@boilerbots Well not sure how much you're trying to dry but I've never needed that much time. Mine can operate between 150-400F and the dehydrate option starts at 1hr and allows 1 hr increments from there. If I'm drying a thick tray of dessicant I'd want to occasionally stir it anyway. I've stuck a temperature probe in the dessicant and (at least for my setup) found you can set the temp notably higher than what it's actually getting to.
This! Air fryer is the one he didn’t test and the one that works excellently, simply the best for the reasons you pointed out. Works even better with the clay too, oil dry is great option.
Air fryers aren't fryers, they are small countertop convection ovens with a PR department. So they should work almost exactly like an oven except they have a fan blowing the hot air around speeding up the process.
@@pjl22222 Well yeah, all convection ovens are basically the same idea but it's a smaller volume of air and ejects it right out of the machine. More airflow means it'll be able to work its way into the material more efficiently and hold a more even temperature. A good convenction oven works fine but there's definitely a difference and I trust setting aggressive temps with it a lot more than I do with my gas convection oven.
I bought a nice big 9 rack food dehydrator years ago, works wonders on filament.
I always did what you were doing and just throwing the little bags into what ever I using to store my filament. I even threw them into resealable vacuum bags not realizing they were probably not doing anything. Time to start drying them first.
I have put a layer of desiccant on the bottom of my filament dryer to act as a buffer, also as an indicator of the humidity inside to see when the filament should be dry enough to use. The only issue is that when the filament dryer is off for an extended period of time, it takes 2 days to fully dry the filament and dryer, so it'd probably be better to refresh the desiccant separately when this happens. I'm in florida, so active drying is a necessity.
Sun bath during a hot sunny day, a full afternoon it will do it. Put in a metallic plate everything will be dry, and it's free energy :)
I'd love to see a part two comparing air-fryers, food dehydrators, refrigerators, hair dryers and inverter microwaves!
I've been using a large food dehydrator that can take 8 filament spools and loads of silica gel packets. When I see 20% humidity in a filament box, I know all the spools and the silica have moisture in them, so I dry them all at once. Once dry, it takes about 6 months before it reaches 20% humidity again.
@@grahamcoster8333 Sounds grand! What model is it and were there any modifications necessary?
@@zachgullerman3183 It's a 9-tray Excalibur Food Dehydrator Parallax. I set the temp to 115f / 46c and run it for 10 hours. We originally got it to dehydrate fruit off our trees and make biltong, which it's been brilliant at. Searching online, the price is way higher than I remember it being 10 years ago. I believe they last forever (ours has), so you might find one second-hand.
I have been collecting the large beads and have a dedicated drying device for which I print large vessels out of ASA. Your video is a great explanation full of data and visual cues. Made me to improve my process. Thank you!
Back in the day, i used to advise people to put their video cassettes in a plastic storage container with as many bags of desiccant as they could manage. In a humid climate the binder agent fails and the tapes start to desintegrate.
they could also get attacked by mold
Excellent video. Thanks for the systematic testing and all the information. It can be overlooked but it is incredible the amount of conflicting information in the Internet about whether or not is safe to use the same oven you use for food for drying desiccant and filament. Here, you explained it really well: you need to use another oven other way there are too many risks.
It seems like it would make sense to throw some desiccant in the hole of the spool when throwing it in a filament dryer to avoid the re-hydration issue.
yep, that is my method since i use a filament dryer
I use a fan driven dehydrator I bought for exclusively drying filament and silica gel. It heats to a max of 70C but it works great, because it constantly moves dry air over the desiccant. It works great and is fairly low wattage. Also, there is no risk of damaging the gel from heating it too much.
I saw someone recently suggest drying filament in a microwave. It could definitely be an interesting thing to look into too!
*slow clap*
Did you watch the video?
I never dared to try this and I'm pretty sure you'll melt it 😅
@@yeroca Yup, from start to finish. I've noticed the quite high temperatures when you let it rip for more than 5 minutes.
But to quote the comment I saw on another video that intrigued me "I dry everything in the microwave, :)
works great and is 20X faster in my experience as well, Have had no issues with overheating (800w) 30-60sec with PETG or PLA"
So take what you want from it ¯\_(ツ)_/¯
@@Joshplv I misread your original comment as asking about the dessicant :D Interesting answer anyway!
I use a food dehydrator for both filament and desiccant. They are designed for drying , so it works very well. And they have a temp setting, so getting the correct temp is also easy.
Had a few smaller silica gel packs, put them in my air fryer to dry them out - just to learn that the bag is sealed by glue that melts a bit above 100 degrees C..(boiling point of water, whatever dungree you're used to)... Things take the time things take, so if rushing the evaporation process ... don't do it while the silica is IN the bag(s) ;ø)
I’ve also used the opposite approach by putting silica gel cartridges (not satchels) in the fridge for a few weeks, while it’s much slower the fridge is a low humidity environment and will pull the moisture out of the silica gel by lowering the relative humidity so essentially the same process at different temperatures
Fun fact: bentonite is also used for cat litter.
Fun fact: silica gel is also used for cat litter.
Came here to say this. Have a friend who runs maintenance at a cat litter manufacturing faculty and complains about bentonite dust making a mess of things all the time, in particular ruining the paint on his car.
And for liquid spills at car accident scenes.
This is a perfectly timed video for me. I especially love the idea of just using regular dessicant beads and humidity sensors.
So 10 minutes in the microwave, another half hour in a convection toaster oven.
I also like to hit my storage containers with my heat gun, from a distance. You can use other forms of dry air as well. Like a little tiny piece of dry ice. You just need a little one-way vent.
I have been storing bags and bags of desicant and have not yet discharged the moisture from them because I have been unsure of how to best do it. I did one test run and the bag exploded in the microwave, likely due to the extreme change in temperature in such a short time. thank you so much for your efforts in studying the effects of each method you have shown!
Nice to see a technical video after a while.
You could have mentioned humidity indicator paper strips which change colour like the beads, but never need to go in the oven.
Microwave defrost is usually the second lower power level.
As bags, I repack everything using stapled kitchen paper double walled bags.
High end microwaves have a DC magnetron and change the power level by changing the voltage supplied to the magnetron. My Panasonic does it.
ah, there are fake strips. hard to fake the beads.
@@rynait fake strips are very rare if you buy by reputable vendors and in any way it's not difficult to check...
They are a practical solution to monitor the air in a container without any risks and without having to change batteries in hygrometers
@@olafmarzocchi6194 Other forum and youtubers says a lot of strips are fake even coming from reputable sources. I only bought a set, for the vacuum bags, set came with strip that did not work. I do not use strips anyway.
@@rynait I have one from Antistat (google "antistat HUMIDITY INDICATOR CARDS") and it matches the hygrometer. 30 pounds per 200 strips, but I got one together with a device
@@rynait I have one from Antistat (search online) and it matches the digital hygrometer. It's sold in 28 pounds per 200 strips. But in general, anything from Farnell/Digikey and so on is reliable. Of course don't go to Amazon or Ali.
This is perfect timing. I've been contemplating buying a jug of silica beads since last week. Thanks!
One warning about silica gel that isn't covered in this video is that silica dust is extremely hazardous when inhaled. It can significantly increase your chances of developing pulmonary diseases like silicosis, COPD or lung cancer. Many places suggest that an N95 mask is enough to block the particles, but you should also make sure you're working somewhere with good ventilation and wash your hands after directly handling it.
Thanks for making this video, it's exactly what I needed. I've been saving them because I knew they *could* be regenerated, but I hadn't taken the time to look up how. This video answers a lot of questions for me, and I'll be looking for some clay desiccant packets for my cat's dry food feeder, now.
I throw away the silica gel, and use 4A molecular sieves, to dry my filaments. As you saw in the graph, it holds more moisture per gram at very low humidities, and when printing in nylon, I want my filament DRY.
I tried molecular sieves myself as well and they work amazing but regenerating them is basically impossible without any special equipment.
@@CNCKitchen Yup. I have dozens of dedicated boxes in which I keep my filament, to minimize the moisture intake, after removing the spool from the factory packaging. If you're going to use molecular sieves, then you can't store the filament in open air. It's just too much moisture. Upside is that you never have to worry about molecular sieves "giving up" moisture, like silica gel does, when conditions change.
How do you regenerate the molecular sieve?
@@mikko3d bake them at the temperature specified by the manufacturer...usually far above 200 °C and more like 300+
I've collected a few, I knew you were supposed to dry them but just didn't want to blow up the microwave doing it wrong. Glad you made this, I'm off to bung a load in Chef Mike.
Stefan, in museum praxis tons of silica gel is used in storage and exhibition rooms, and it has a well established method for around 50 years, where setting and keeping a certain humidity level that suits the given artifact is key, and since silica gel in large amounts is not cheap keeping it 'alive' is also a factor. Turned out microwaving the silica over and over again -since it's based on inner friction of the heated object and not by convecting heat- it will damage the inner structure of the silica pretty soon resulting the rapid degradation of its absorption capability. So, it's not used in professional praxis.
(Personally I don't use microwave for my food either, but that's another topic.)
so, how did they dry the sikica gel ? or did they replace it regularly?
@@koboglo6973 yes, inquiring minds want know...
I second koboglo's query.
@@koboglo6973 in old-fashion ovens at around 110°c while the humid air is vented off. Silica is spread over multiple perforated plates in thin layers to expose the largest surface possible, then put in hermetically closed glass containers while still hot.
@@h4z4rd42 yep, storing dryed silica gel in a glass container while hot is a good point
Consistently useful information supported by detailed analysis. Since I will be moving to a location with 80% indoor RH, I need to take drying a bit more seriously!
Have you tried Activated Alumina? I've been using it since the indicating silica was found to be dangerous. The alumina has been great about keeping my filament in bags and AMS dry and is easy to reactivate in a toaster oven I have in my shop.
I’m using alumina as well. Its been great, much better absorption than silica gel
Great video Stephan, with your usual thorough testing. I use 2x 20g sachets of Wisedry desiccant in each of my 4L airtight containers. These are colour indicating silica gel sachets. The instructions say to put 5 sachets in the microwave and heat for 3 minutes at 80% power, then turn the sachets over and repeat. It dries them out nicely. The beads return from green to orange, and the sachets weigh exactly 20g after drying. However, I was concerned about the microwave power setting, as the glass turntable gets incredibly hot. Using defrost mode seems like a sensible precaution, but then repeating cycles over and over again sounds like too much hassle. I used to use a fruit drying oven, but it was too big, so I got rid of it. Big Clive's suggestion to consider an air fryer sounds interesting, so I may look into that. Thanks for your great work.
Good to see you testing the beads for absorption after drying, and it's good to see they still work. I bought one of those drying bags from Amazon that hold 300g of silica, the product states it can be 'regenerated' in the microwave, but as far as I'm concerned you have to be extremely careful doing this otherwise the life of the bag is drastically shortened. The MW is a great way of drying fast, but they're almost TOO effective, they heat up too much and destroy the micro-pores inside the silica as the water energetically escapes, makes sense that this should be around 100c. Part of the issue is that stupid semi-pwm method they use in microwaves, as a 300g semi-saturated bag can easily get way past 100c (in areas) in a single ON pulse. Perhaps it's possible to pull apart a MW oven and replace the pwm component with much higher frequency pulses, assuming magnetrons can even be driven this way.
Just after watching this video I tried to dry 200 g of Silica in the MV. Initially on Defrost setting (240 W), but as the pearls started to "Pop", I switched to the "Keep Warm" setting (130W) in 10 minutes intervals. Lost just about 18 g of water in 1 hours time.
Thanks for the great tip.
Another technique that would be interesting to see is putting them in a sealed container and drawing a vacuum on it. There are custom-toy hobbyists that have cheap vacuum chambers for removing bubbles from resin molds, so having the means to do so isn't unreasonable. The moisture in the gel should then boil off at room temperature, removing the risk of melting anything, at the rate of however long it takes the air compressor to draw a vacuum each cycle.
The low air pressure will also affect the relative humidity, tho. Boiling off even a little bit of water will significantly raise the relative air humidity, so you'd probably need many, many runs.
@@marcus3d you could easily break the vacuum by releasing a small amount of air. The significantly higher concentrations of nitrogen and oxygen would displace the high RH low pressure atmosphere.
@@mattpatt The smaller the amount of air, the more often you need to replace it because it hits high RH. Even at sea level pressure the air will need to be replaced quite often, and if you remove half of the air that doubles the number of replacements needed. You're gonna be running that compressor a lot, I think.
@@marcus3d is RH an important factor though? As the absolute pressure reduces then I imagine the driving force for adsoption reduces too. I guess the silica gel adsorbs water selectively but in a normal air mix the partial pressure of water is low. In the vacuum you describe the RH is high and so the contribution of water to the absolute pressure is high but I imagine it wouldnt take much vacuum to significantly reduce partial pressure of water. Unfortunately I'm not an expert in this and can kind of guess but not be certain. I do know from experience that when vacuuming refrigeration systems it is common to draw a deep vacuum and break with nitrogen only 3 times and that is considered good enough to "fully remove" water. To the extent the goal is
@@mattpatt RH is the key metric. It describes how saturated the air is. When the RH of the air equals the RH of the filament the transfer of water stops.
I don't know about removing water in refrigerator compressor systems, but normally the compressor is in refrigeration just to change the temperature back and forth, so that we get 2 different temperature differences, to enable the transfer of heat in 2 different temperature environments. (One colder, one warmer.)
All the things I always wanted to know but never got triggered enough for to actually go after it and figure it out. Thankfully you did :) As with lots of things. Thanks, great video again!
When I had easy access to cryo-equipment I used to freeze dry silica gel (and fruit slices). I don't think it was particularly energy efficient (and tended to fill up the moisture trap in a hurry when I added to the collection). But I wonder if hanging the heated bags to dry in an ordinary freezer (so that most of the heat/nrg exchange is by convection/evaporation rather than conduction) would have a measurable effect.
(edit; 19min, 1 like later:) -oo- if suspended in a container/jar (w/ thread), then we'd get to see the water/whatever that was still in the bags/packets freeze to the walls, (edit 2:) and not worry about condensation affecting them. ( I might try that with some of the packs from my prescriptions, since they're explicitly only supposed to be "used" for {3 months, or 50 open/close cycles} without recharging. )
(edit 3, 27 min later:) Wait -- Why haven't I just been using a 'vacuum' bottle and the freezer/winter to dry them? I just need to figure out where the pump got to... )
He tested using a vacuum pump on filament a while back, and for some reason that I don't really understand, it wasn't as effective as using hot air, though it did reduce the moisture content to some degree.
Thanks chap, just the insight I needed without even asking! I have a large old pickle jar full of desiccant packets saved from COVID tests.
*Bentonite is basically cat litter.* I see a great opportunity for recycling used cat litter here: *ahhh, I love the smell of microwaved cat turds in the morning!*
I live in a dry state i never thought my silica packs would get much moisture, after watching this i thought i would try my sunlu with the Turbo Mod to at least check. Was i ever wrong, they obviously had lots of moisture. Thank you for posting this informative video.
I recall people using round food dehydrators for filament drying a couple of years back. I accept that this really only works as long as you move the dry filament into a moisture tight container immediately after drying. What I was wondering about, and don't really see it mentioned other than possibly as related to the Creality filament dryer, was if one kept a dry tray intact, and spread out the filament bags on it, would that give useful desiccant drying as well. I imagine that it would need a longer cycle time, but depending on the heating mechanism time, that may not be an issue. I would imagine one would still want to drop the resulting desiccant into some variety of dry box to keep it dry.
I bake and reuse these all the time. I've learned that what really matters is the sachet, not the desiccant media. Some bags are made of an expanded PTFE that shrinks and becomes impermeable if you bake it in an oven; they're designed to be dehydrated in a vacuum oven. Others are just paper.
Today I have a big tray of calcium chloride in a fish tank. I put the desiccant bags in the fish tank and the CaCl sucks the water out of them slowly over time without heat. I bake the CaCl dry when the tray fills with water.
Great video, thanks. An Air fryer might be the thing to use. It has the control but uses hot air blown over the stuff so should be fast. They are also said to be more energy efficient than a microwave. Also I do not have an oven.
Great work Stefan… your videos are greatly appreciated… great information, very useful, consistently and systematically demonstrated with well crafted and precise tests and measurements…
THANK YOU I've had dozens of users ask me if they can use my SPILLPROOF ams desiccant boxes in the microwave, I always tell them I've not tried it and wouldn't because the beads can get extremely hot and melt the container, now I know for sure, over 100C is crazy! Definitely would melt PLA and PETG THANK YOU
Over 100°C is nothing. Drying molecular sieve desiccant in the microwave, I've inadvertently turned it into lava...
Info is very good especially the microwaving process
Great investigation Stephan, very interesting. I think everyone who 3D prints needs to know this!
I made my own reliable four-reel digitally-monitored self-regulating auto-rotating filament dryer from a few things I had laying around. 🤔😉
Thank you, Stephan. This really lit up my lantern. I used to do the same thing; I will dehydrate them before using them in the future.
Merci Stephan, cela m'a vraiment éclairé. Je faisais la même chose, je vais les déshydrater avant de les utiliser à l'avenir.
I once had a wheelbarrow full of 1kg bags of silica gel.
They were shipped (or rather LKW'd) with a Trumpf TruBend metal bending brake (Abkantpresse) to protect the machine from rust.
I recently purchased some filament dryers, when I had dried the filament by itself for quite some time but I figured I would throw in a a few silica gel packs to preserve the low moisture. I came back to find the moisture level inside the filament dryer had risen and there was even a bunch of condensation I had to wipe off. My conclusion was that the silica had picked up a lot of moisture in transit I when I heated it up it was releasing it back into my filament.
this guy is legit been around a long time, if he says this is the best way it really is the best way!!!!
Drywall, gypsum, is a hydrate of calcium sulphate, it has a bunch of water embedded in it. One can dry it out in the oven at about 230f 110c. It will work as a cheap desicant in bulk that can be easilly recharged over and over. But, using too much heat will still dehydrate the calcium sulphate but the crystals will change to a form that doesn't absorbe moisture well and it won't work as a desicant anymore. But, that is avoidable by not heating over 230f oe 110c.
Another method I found very effective is putting the bags in a vacuum container, like the containers and vacuum pumps used for degassing resins in composite manufacturing. Very effective and no heating that can damage the material or the enveloppe.
I dry my desiccant bags in the microwave on high for 30 seconds then let them on a small fan cool for a few minutes. Then I bump the time up to 40 seconds, let them cool. Repeat until the bag feels dry when you take it out (or for about 4-5 cycles). The clay type desiccant can't handle this method and will melt the bag. This method is probably faster than the defrost power method you describe. Great video!
I’ve been collecting filamenr desiccant bags for years. I've dried my bulk silica beads in the microwave and have been happy with how well it works. The bags I’ve been collecting in part are in a big bag and being used to counterbalance the boom arm for one of the studio lights. Repurpose is sort of like reuse, right?
Sounds like a reasonable way to re-use them.
I collect these too. I learned to recharge them many years ago. I recharge with a toaster oven. As cool as it is that it is possible to recharge with a microwave, I won't be doing that. Microwaving anything without sufficient moisture present can damage the microwave. While it's probably safe to microwave as little as half a cup of fully saturated desiccant, the more moisture you remove, the more likely it is to start causing damage to the microwave. That said, I do want to insulate my toaster oven really well, because those things typically have no insulation and just waste heat like crazy. Given your experimental numbers, it probably wouldn't be too hard to insulate a toaster oven enough to have efficiency levels close to that of the microwave. (Maybe better, as microwaves also leak heat pretty fast, when run for long periods of time.)
I mainly use my silica gel desiccant for its intended purpose. I don't keep clay desiccants. I'm not super concerned about the environmental factors, and silica gel is superior.
That said, some clay "desiccant" packets are not actually desiccant. They do have some desiccant properties, but certain prepared clays also absorb other elements, including heavy metals. These are often what the clay beads are, and they are similar to the clay beads used in water softeners. They can be recharged with salt water (I forget the process, and you may need a specific salt, like the calcium chloride used in some water softeners). The only use I've found for these is adding to garden soil. I don't bother trying to recharge them, as they are very unlikely to have been fully exposed and saturated, and some of the things they can absorb are actually good to leave in them for your plants. They can also filter out and bind some things that are toxic to plants. I'm not sure a packet now and then is enough to make a difference, but at least the material is being recycled in a useful way instead of being tossed in a landfill where it will be generations before it can provide much value.
Anyhow, I recently discovered something: Silica gel can be used to make high purity water glass. Water glass, aka sodium silicate, is a substance that has very good thermal properties, is water soluble, and dries to a glass-like transparency (supposedly; I haven't made any yet). Technically you can make it with silica sand, but sand typically has a ton of impurities. When used in refractory materials, it can act as a binder or even an adhesive when dry, and with sufficient heating the sodium will separate from the silica, removing the water solubility and producing an even better refractory with good structural properties. Anyhow, to make water glass with silica gel, you just react silica gel with sodium lye (often sold as drain cleaner crystals) in a solution of water. The lye will dissolve the silica gel making sodium silicate, which can then be added to a firebrick recipe or (according to someone else on RUclips) mixed with garden lime to make a very strong refractory adhesive. I'm currently working on building a new smelter and forge, and this time I'm going to use water glass in the mixture, in hopes that the structural benefits will allow me to use more perlite and vermiculite for even better insulating properties than past ones I've made. And I'm going to use the lime/water glass adhesive to coat the inside of both of them for improved structural integrity. Wish me luck!
But yeah, that's how I'm using my silica gel! (I have plenty, so I'm only need to use a small amount of what I have for this project.)
While working at a PC components company in the 90's I collected about 400 fabric bags. I emptied them and dried them in a gas oven and used them to really really dry things. A dead frog was the most memorable - it weighed almost nothing and was surprisingly strong - it lasted for years too without rutting.
Oh, and regularly stirring/rotating the beads while they cook releases a lot more steam. It's as if the top layer traps the steam inside but it was a large metal bucket full.
16:46 makes sense since the whole point of a microwave is to shake the snot out of water molecules!
Thank you for the video, I was planning to do similar tests but you did it first, you saved me a lot of work !!
Also, I know the point of your video was to reuse dessicant from spool bags, but you can also buy large amount of silica gel in most supermarkets in the form of...cat litter !
Indeed there's a lot of different litters for cats, and some of them are just large and cheap bags of silica gel (it's usually written on the bag). The only drawback is that it's actually bad as litter for cats (silica gel bits are very hard and sometimes sharp and can damage their paws...) so buying it kind of support a bad product, but it's hard to find cheaper than that !
Another major tip. It's extremely hard on a microwave to run it dry, they tell you to put in a cup of water if you're microwaving a taco shell or some other mostly dry item.
Put a small amount of water in a bag, then inside another bag or two. That way it won't leak out if some leaks, coverts to steam, etc. Yes it will split off some of the energy, but it gives an OK target, and any steam will stay in the bags instead of having an open cup.
On the point of not expecting or thinking about using a microwave for drying. I know a fellow who's good with electronics was asked to see if he could repair an industrial lumber drying kiln. It turns out the kilns used for making lumber are basically just massive microwave ovens. You can basically walk around it and look at the circuit components because of the size needed for capacitors and resistors in something that works at those wattages. At the end of the day he found a capacitor about the size of my head that was blown.
I'm also kind of curious now. If we outfitted your custom toaster oven that has the thermal couples in it. With a humidity sensor and a fan and had the fan kick in when humidity reached a certain saturation could we improve the functionality and cure time of the toaster oven by evacuating the humid air on interval..
I used the blue/pink silica. I dry them together inside my spools on a terrarium heating pads with a card box with a few small holes( the card box where the rolls are shipped in) on top. It works great and is very cheap.They get a very deep blue color. I only rotate the spools a few times. I store my spools with the silica inside them using vacuum food sealers. I make the bags a bit bigger so I can easy reuse them without wasting a lot of plastic when cutting them open again. Before that I used those Chinese vacuum bags with valve but found they where one time use only, so that was a waste of money.
How hot are the pads? Could it help to pre-dry the silica in the microwave, then put in the box with pad?
@@javan6982 I use 15W pads that cover the spool, they can be regulated. I don't have a thermometer. So I can't really tell the temperature. If I have to guess by touch I would say around 50 degrees. they feels pretty hot.
Я собираю пакетики с силикагелем и периодически сушу его в микроволновке. Мне понравился ваш способ сушки материала в вакуумной камере на столе принтера в предыдущем выпуске. Мне этот способ помог высушить нейлон, который никак не мог высушить в духовом шкафу в течении 3 суток при 90 градусов. Материал очень сильно не хотел отдавать влагу, но я благодаря вам его победил. Спасибо! (I collect bags of silica gel and periodically dry it in the microwave. I liked your method of vacuum drying the material on the printer's table in the previous issue. This method helped me to dry nylon, which could not dry in the oven for 3 days at 90 degrees. The material was very reluctant to give up moisture, but thanks to you I beat it. Thank you!)
I've usually used the microwave method to rejuvenate sachets, along with some kitchen towel underneath to absorb sweating on the base. Like Stefan, I've found a traditional oven gives the best result, but microwave does work well. Just a few beads of the toxic orange colour indicating ones, much fewer than Stefan had, is sufficient in a mix of white untainted beads to judge whether it's time to recharge them.
The efficiency of the microwave makes perfect sense. Its a bit like induction heating since a microwave really efficiently heats up water, so it heats up the filament by heating the water that you are trying to remove!
I just use calcium chloride, which absorbs 7 times the amount of water than silica beads, and is way cheaper. My drybox generally has a relative humidity of 7%. The only drawback is that it turns into a liquid when wet so just put it at the bottom of a bucket and seperate it from the filament with a divider. You can bake it in the oven as well. Maybe next video idea?
I've obserbed that if I put in a very wet TPU or PVA that is even slightly mushy, it dries it fully in a week or two if it is terrible. So no dryer needed.
I live in a place with generally 70 to 90% RH.
As a thirty something guy i was planning on using my air fryer on dehydrating mode, 80c but with constant hot air flow.
Was hoping to see an air fryer here!