Nice work on the home made vac unit and the results. I cast Sterling Silver jewellery with a Kerr vac unit and if you dont mind here are a few tips. Reduce the large wax base (button) in your tree and you will have much less wax to burn out. Look at a commercial rubber flask base to see what I mean, the button is usually part of the rubber flask base so you may wish to improvise something similar to reduce the excess wax. Steam de-waxing works well, keeps the wax of your furnace and re-hydrates the flask prior to burn out (more steam for wax elimination). A simple rack over boiling water with flask opening downward for about an hour or 2 is sufficient. This will make for a cleaner burn out. When the wax is fully burnt out of the flask, the flask mouth will be nice and white as all the wax residue has vaporized. try not to exceed the investment max temp as the gypsum binders in the investment will begin to break down. This might be what cased the flash on your coins. Feel free to message me if you wan some more detailed info.
Mr Veg, when I was in high school my metal shop teacher taught us lost wast casting because he did jewelery on the side. He used a centrifuge to get the metal into the mold. I love the vacuum method ,you don't have to have a mold flying around along with the molten metal. That is great detail. I remember him showing us a bee he had cast and it had the fine hairs on the body of the bee. Great video! I truly appreciate the knowledge that gets passed around on the internet. I am impressed. Thanks!
Thanks Mike. I agree, one of the great things about RUclips is the information that's shared. I learn so much from people writing in to me and sharing their knowledge. In turn I pass it on here. It's invaluable : )
I know you posted this a while ago, and I'm unsure if you still use it, but if you do, one thing that I think would benefit you, is add a tank in between your pump and your chamber. While your metal is heating, you can draw a vacuum on the tank, pour your cast, and flip a ball valve to pull a vacuum on your chamber from the tank and then keep pumping to maintain. Youd get an instant draw that youd then maintain. Minimal heat loss from the pour.
This. This is the proper way to pull a vacuum on anything that could introduce process materials into the pump. This is the proper way to pull a big volume into vacuum rapidly such as when doing sheet vacuum forming.
You can use your heat sensitive vacuum pump if you vacuum an air tank, then attach the tank to the mold install a shutoff valve for a quick vacuum pulling the metal in using only negative pressure from an air tank thus the vacuum pump will be safe and totally away from any and all heat while the hot liquid metal begins to be pulled in the mold much faster and more efficiently. Thanks for all your inspirational videos. Keep them coming!
Thank you SOOO much!!! I have seen people from Men at Arms Reforged and a couple other videos where they have soo much to say and do, that they mention what they're doing in such an off hand way that it literally explains nothing!!! "'We pour the liquid metal into the mold while sitting on the vacuum chamber then it'll go into quench..."' it raised soo many questions that I've been looking for answers to for almost a year now!!! And poof in one video you hit them all!!! Thank you!!!
Thanks very much. You're very kind. I'm just an ordinary guy with varied interests. As I explore and learn, I like to share my experiences. I hope you have the chance to look over some of my other videos : )
@@vogman I've watched several of your videos!!! My 3 favorite are the Mehrunes Razor, the Viking Axe challenge (personallyI think yours turned out better than the other 2 guys) and the vacuum chamber... I had actually already seen the video for pvc hand pump you used to designe your pump. I plan on making a vacuum chamber based on your design!!! Thanks
@@vogman i have not gotten to the lost pla video yet... im currently studying your electric furnace videos... my first furnace is a perlite and sodium silicate ram up in a metal can with a Satanite refractory coating and a propane burner.
Thanks for the incredible knowledge. It's taken me ages to find out exactly how the vacuum casting process works,but now after explaining how the investment plaster is pourous, it all makes sense!!
Nice results indeed. For drawing a vacuum during the pour most effectively, without ever putting any expensive pumps in the line of danger, the simplest setup is to have a vacuum 'reservoir'. Just pull a tank empty with your pump, and connect it via a valve to your flask, then open that valve directly after the pour. That only gives you a short burst of vacuum that is quickly reduced; but thats all it takes. Once you draw the metal into the detail, there isnt anything forcing it back out again. Its more important that you get a strong effect going quickly, so it can do its thing before any of the detail solidifies, than the length of the pull. Your chamber would do as such a reservoir; its just that you are better off placing your flask over its vacuum release valve, than on top of it without a valve. Thats all theory though; never made any such detailed casts myself i should add!
Perhaps use some plastic plumbing pipe as a vacuum accumulator? Or an old welding gas tank that's aged out of pressure service? You could use your nice vacuum pump to pull the accumulators down, then isolate it and use the vacuum you built up for casting.
Robert I worked in a prototype shop and we did vacuum forming on pvc plastic. Our vacuum frame had a big tank that we pumped down and then was released. We only had a couple of seconds for the soften plastic to form to the mold before it would reharden. But that was a great suggestion!
This, I would go with the welding tank, and black gas line and a ball valve. as a bonus the larger the tank the longer it can apply vacuum, IE you could in theory open the valve, and then pour, and have the vacuum be applied through the entire pour till it froze.
That artifact or flaw was caused by adding the vacuum after the metal was poured. The metal filled the mold.....mostly. The very surface or skin of the metal started to solidify. When you added the vacuum, it filled the mold all the way but it couldn't cover or "erase" that first edge. Great video!
About 25 years ago, I used three old helium bottles as a vacuum reservoir. Pumped down the bottles ahead of time, and then opened a spigot to apply the vacuum as I poured 14K gold into the mold. Worked great for casting a wedding ring.
You should try adding a valve between your vacuum box and where the casting is placed. Then you draw a vacuum in the box and then place the casting on top of the vacuum pad and them turn the valve allowing the air in the casting to flow into the vacuum box. You could use your round vacuum box for this. I would create a little support stand to hold that silicone pad and run a brass fitting (hose fitting) into the silicone pad and do the same to the plexiglas/acrylic top of the vacuum chamber - then run a line from the silicone pad to the vacuum chamber (the valve would be placed on this line). You don't wan't to fill the chamber with stuff this time, you want it empty. Draw a vacuum as high as possible (you can use your good pump for this b/c it's drawing room temp air) and keep the vacuum running up until you pour. Then at pour time, shut off the vacuum, pour the casting & place on the new holder and then open the valve and the vacuum chamber will pull all the air from the casting into the chamber and you don't need to worry about pumping fast. You could also do the same with an old propane tank instead of a vacuum chamber. Maybe draw 50% vacuum (the larger the tank, the better) and then crack the valve to pull air from the casting. Another way to do this would be to add a little water to a propane tank, heat it with the valve open until it steam exits. Remove from heat & close the valve. Allow to cool. You now have vacuum inside the tank. Connect hose/tube to casting holder & open valve once poured.
I just ran across your video and it's great. Thankyou for sharing your skills with us. Have you seen the you tube videos on making a vacuum pump from a fridge compressor? I just finished building one for bead making, with glass. I used a coil of copper pipe just as it came from the store with an old computer fan blowing air through it. It works great and mostly free. I'm looking forward to exploring the rest of your videos. Keep well and God bless.
Wow - what tremendous results! The close-ups are evidence enough that it´s well worth using both dedicated products such as investment plaster and proper wax as well as a vacuum chamber. Now that you´ve effectively removed the "cost" obstacle from the latter I suspect that many of us will be improving our game after seeing this compelling video.
That's exactly what I'm about. When your budget is low but your ideas are lofty, life can sometimes get you down. But if you can find a way that gets you pretty darn close without breaking the bank, well, that's what floats my boat. Then sharing that idea so others can benefit launches said boat. Gosh I'm feeling nautical here : ) But yes, good wax and good investment plaster are two things that can't really be bettered (well, not so far).
So started off watching one video, then one more and so on....good at explaining and goes into enough detail to make sense. Sometimes wish i had a job and i could afford cool things
Something to cool the air coming from the chamber would both protect the pump and increase performance. With your setup, filling the box with ice packs might do the job.
Good suggestion, but are you aware what happens to water in a vacuum chamber? It boils... I don't know whether the hand point could generate sufficient pressure for that though. In truth I had no issues at all. I'll probably look at that in more detail another time, but everything came out the other side just fine :)
Water near the freezing point needs more vacuum than I expect you're pulling on the plaster mold before it boils. I was also thinking sealed ice packs, not bare ice.
It could well help... but I didn't witness any reason to even try in honesty. The pump was unharmed. The paint inside the vacuum chamber didn't "brown" with heat. The plastic hose didn't melt. In short, there wasn't the heat that I expected there would be : )
VegOilGuy if you’re home made pump wasn’t getting hot enough to melt, I doubt you’re professional vacuum pump would either. As long as there’s a few feet of hose in line there shouldn’t be a problem, If there is a connection pipe will melt and save your pump.
Good job 👍🏻 my only problem with is the writing is so small and quick I can’t read it before it goes away. Casting came out great though! Have you tried regular plaster of Paris mixed with some play sand? Makes it stronger to burn out the wax or pla
I haven't experimented with PoP and a vacuum yet, no. I believe it's not porous. But with the correct additives who knows what could be cheaply achieved : )
If you have a vacuum pump that can't take heat, perhaps a coil tubing and a fan or bucket of water could reduce the heat enough for your pump. Nice video, thanks for sharing.
for cheap vacuum pumps check with old mechanic shops, years ago AC work was done with a set of manifold gauges and a separate vac pump. But 20 years ago the epa began required the used of reclaiming machines first for R-12 then for 134A. so the old stand alone pumps have been setting on the shelf for decades primarily being in the way. Now that R-12 is phased out I see the re claimers for it fairly often for prices ranging from free to $100. Last I heard they are going to change refrigerants again, which will likely create a whole new glut of old machines.
I know this vid is almost 3 years old but like to add, those artifacts are likely from fractures in the investment plaster during burnout. You can try adding graphite to the plaster and/or talcum powder. Keep in mind that talcum powder will add more porosity to the plaster, so use it sparingly.
Your making great progress. Few tweaks like properly weighing plaster mixture, and completely drying and heating it much more slowly will help(chemicaly bound water breaking down can also produce enough expansion to crack mould if you don't go slow enough. Also look into ceramic shell casting materials. For your wax using a better silicon you can preheat the mold to be as hot as the wax.
Try using a cnc mold. You can machine the wax to a very high degree of detail. Additionally add a valve between your mold and the vacuum chamber. This way you can draw a vacuum into the chamber prior to pouring. When you pour you can open the valve and it will draw in fast and stronger than starting the mechanical or electric vac pump, which needs to draw the air out of the plenum. Essentially your macdonald cups are just reducing your plenum size. The larger the plenum, the longer you can maintain your high vacuum draw on releasing the valve.
You can try finding the leak with a sponge and some soapy water, like when you try to find the leak in a tire. (Of course you should pump air ínto the chamber so the bubbles will form on the outside)
Well done Geoff another great video through the whole video I was asking myself how is the vacuume transfered to the plaster and you waited to the near end to tell me. Great result..
Thanks Luke. One of the problems with doing anything like this is I know why I'm doing it and what I expect to happen. I always try to take the stand that the viewer doesn't and offer explanation. I often worry in case this is a little over-the-top, but messages like yours make me thankful that I did what I did. So thanks for the reassurance : )
That's very kind but I have my doubts. I'm unwilling to pour molten metal into a large fruit or run over an expensive cell phone with my car, which means I don't have mass appeal. But I'll stick to doing what I do 😁😁😁
Also its thanks to you im now starting to make my own rings , once i get good at cheaper metals then ill move on to making a gold one and so on . You are a huge part in changing my life , and many others . Keep doing what you are doing bro . If im successful i wont forget
You've got the right idea. I'm still doing exactly the same. I started with scrap metal - which will never get you perfect quality - then moved on to bronze ingots. I've dabbled with a little silver, but it's expensive 😀
You could probably make a heat shield inside your vacuum chamber for existing hot air alil heatsink .those extra hanger s are from casting mold it cracked alil.
Thank you good sir. You're a gent! One of my many annoying qualities is that I don't like things beating me. If I know something is possible, it eats at me until I manage it. At which point it then generally loses interest for me (yet another annoying quality).
Cover the whole outside of vacuum chamber with silicone and apply vacuum for 4 minutes then one more layer and let it cure. Could probably use latex paint or something that is watertight and flexible when cured. Edit: great casting result 😀 Very impressive details
Using a vacuum isn't my method really... I just did what the experts do, but this cheap version makes it accessible to guys on a lower budget. Doing that always gives me a buzz.
We had some pretty good luck pouring pewter coins in a split mold carved out of soapstone with a small CNC milling machine. We made the mold, and a friend poured around 100 coins with it as I remember.
Inspirational stuff Geoff. Good quality video and a calm and informative narration, mixed with a bit of humor makes your content very much worth the time. Thank you.
@@vogman would i be able to use a small air compressor instead of the hand pump? maybe something like this? www.amazon.com/Campbell-Hausfeld-FP209499-Gallon-Compressor/dp/B002O15NRS/ref=sr_1_7?keywords=air+compressor&qid=1577601182&s=hi&sr=1-7
Try breaking the vacuum casted metal in half and look at the grain structure. I've heard if you do it in vacuum, there isn't any crystallization, the whole piece becomes a single crystal.
Lol saw this and got super excited like I’d love this video. Clicked on it and I’ve liked it already so I’ve had this same thought before and forgot lmaooo
Holy hell Geoff there friggen perfect. That investment plaster is awesome . It’s a shame your not in Australia as I can get those wax chips from my work for nuthin but we only have yellow and red no blue . I definitely know not to challenge you in a coin reproduction 😳😲. Great stuff matey 🤙🏻👍🏻😁.
It's incredible. I was scared people wouldn't get the idea and would just see the ugly lines... but to me it didn't matter what I was casting, I just wanted some obvious detail and a means to replicate it easily. I think I've found it. You have access to wax products? Mate, you've got to try lost wax. In terms of accuracy I believe it's arguably the best form of casting. It's possible to create things that couldn't be done in sand and only a machine could produce in foam. You'll love it!
Nice video. If you used an old fire extinguisher or gas bottle (make sure to flood it to drive out any gas) or even demijohns you could make a "vacuum reservoir" between the pump and the chamber to give an original hit of vacuum before you get pumping.I've heard of old fridge pumps being used to make vacuum pumps and 3" copper pipe and a foot pump being used to make a pressurised wax injector - not that I've made any of these myself.
Toward the beginning of the video you mentioned that the vaccum pump can't handle heat. Couldn't you plumb the vacuum through some coils of copper tubing and submerge the copper in water or even ice water to keep any heat from damaging the vacuum pump?
Very nice video. I would like to ask how the liquid metal inside the plaster is affected by the vacuum under the plaster since there is no communication between them?
Not sure how vacuum leaks are supposed to be checked but I work as a pug mill operator making ceramic tile. We hold a lit candle up to check for vacuum leaks. The flame will get sucked right into the leak without blowing the candle out. Not sure how big the leak needs to be to be clearly visible though.
Ive never tried it and have never seen anyone else do it but i wonder if a vibrator or tapping the sides of the casting wouldnt get rid of air pockets?
It's unlikely it would work. Ideally the metal should set almost instantly. The longer it remains liquid, the more it will attract porosity, etc. But good thinking 😁👍
Have you looked into centrifugal investment casting? Jewelers use that technique for casting intricate jewelry. The g-force from the spinning centrifuge pulls the liquid metal into the mold.
Hi Peter. My original plan was to build a centrifugal system... but they take up a fair amount of space and you've got to balance them very well for safety. I found this vacuum set up MUCH easier with excellent result. Safer too... amateur builds spinning molten metal at hundreds RPM is a terrifying thought ; )
Checking comments to see if this was already addressed, I did it in high school, super simple setup and honestly I think it is a better faster option, also used displacement to make sure I didn't waste too much metal. I also cast scorpions and other insects.
@@vogman I used to cast for a jewelry shop, and I used a centrifugal casting machine with a built-in electric furnace. It was fast and reliable, and easy to use.
I use centrifugal casting because you can just melt the metal in place and let it go. The key is safety. I built a shield around mine with a lid so as soon as the metal is melted I put the lid on and duck behind my shield and let it go.. Picking up a crucible full of molten metal is much more dangerous in my view.
Great tutorial on lost wax casting. Have you considered a way to create the vacuum in your box before the flask is placed on the silicone pad then, after pouring the molten metal open a valve and “dump” the vacuum into the flask? You would have to construct a stand on the top of the box with another valve, but I am sure you could come up with a clever solution. Doing the vacuum as a “dump” would have the same effect on the flask as you were wanting to have by adding the containers of waste plaster: faster application of vacuum force.
@@vogman I'm trying to get into stainless steel casting for objects about 3-6 inches in length and width. Can you offer advice particularly with a machine that reaches that high temp?
Wouldve ran your good vacuum pump and added a chamber inline to prevent sucking in any heat. Could’ve gone about that a few ways including a mini radiator with fan blowing through or water cooling a copper loop. Either way cooling the air wouldn’t have been too difficult. Alternatively running 15-20ft of vacuum hose passing through a bucket of water may have been enough.
To locate your leak in your vaccum box try pressurising in it then using some soapy water. It might work. if air cant escape then it shouldn't get in. Great video by the way.
You probably already know about the use of a casting well that uses centripetal force to achieve the same effect of drawing the molten metal into your mold. It has the advantage of being able to keep your mold at high temp while casting. I think the extra flash or fins may be from defects in the investment plaster due to shrinkage of the plaster. Anyhow, I found your ingenuity to be great and it produced a nice result. Thanks for the video!
I've been watching Alec Steele for a while and this popped up in the similar videos lists. I'm glad it did, very entertaining and great explanation of the whole process. Thanks so much for sharing. I'm looking forward to watching more.
Thanks very much : ) I'm afraid Alec and I are in a different league. Whilst he has every tool available and an extremely large budget to play with, I have basic tools (that most DIYers have) and barely any budget. So I strive to be innovative, finding cheaper but equally good ways. If you look at my more recent casting videos, you'll see this budget casting vac really does work. If you look at yesterday's video, I saved a few hundred pounds by building a vibration tumbler for £20. If you can cope with that, then you may enjoy some of my content. Feel free to let me know : D
@@vogman Thanks for the reply. You may not have Alec's budget but your results are great. Its very encouraging as I'm also on a low budget and want to do so many things in my little workshop, a tumbler is a project I'm also collecting parts for. I'll be watching more of your videos in the future, thanks for sharing
Your videos are awesome man! I'm so glad I found your channel, your work has inspired me to finally start metalworking, something I've wanted to do for the last 20 years but never been confident enough to invest in. I finally have my furnace and kiln set up, and I just need to set up a vacuum system and I'll be ready for my first trial run. Don't have to work for another 10 days, so I might get on down to the Home Depot this weekend...
I like this. I started with an old Vinyl Album Turntable set up with some rubber bands-you spun it up, did your Investment and casting then released it and it spun like a Centrifuge. My latest project is an electric motor from either a lawn mower or a kids street gokart but this pump you built looks a bit more reasonable to do. I can use one of those motor to build a homemade grinding wheel instead. :)
Mark, never let me discourage you from mechanical chaos. Have you not seen my lawnmower? ruclips.net/video/-ezH92dfZqQ/видео.html You're a brave man. I initially toyed with the idea of building a centrifuge but chickened out. The idea of molten metal spinning violently at high speed filled me firstly with excitement and then more sensibly with panic. This pump method is incredibly easy (I've demoed the pump in another video if that helps) and the results are astonishing. It's quite astounding how little vacuum is needed, and that's got to be safer than spinning metal... though not as exciting : )
I've seen several diy vacuum pumps using fridge pumps. I've also seen glass demijohns with a couple of valves in between the pump and the chamber to act as a store of vacuum (can you store a vacuum?) when the actual pump wasn't fast enough to drop the pressure straight away.
Great stuff. Well explained and in laymans terms that even a spanner twirler like me can understand. I'm about to venture into the new world (for me) of silicon mold casting and I have no doubt that something like your vacuum chamber will improve the outcome(s) of the models I aim to produce. Cheers....You have a new subscriber from the land of convicts, cold beer and hot pies!
It's great to have you here Mark. I agree that a vacuum chamber is a very useful tool for silicone moulding. If you check out the video I made last week (Miniature Skulls) you'll see I made a simple silicone mould for that using my vacuum chamber. If you have any questions, feel free to drop me a line mate : )
Just 're-watched' this and had another idea. Old 13kg propane cylinders are freely available and easy to clean out any residual gas. How about preparing a cylinder of vacuum, harder than you need, then using it as a reservoir. It would enable more control of the draw-down and be constant rather than pulsed.
or just put a much bigger pouring cup on your mould to increase the pressure so the mould fills fully (and maybee increase the temperature of the metal if the mould is'nt filling) and to provide a source of molten metal while the casting freezes eliminating shrinkage faults
Great video! So the mold got vacuum sucked through that tiny hole in your chamber lit? Only air flowing through the bottom of the mold. Who would have thought... I thought about perforating that metal pipe you bought and hanging it in a bigger hole through your chamber lit. Wouldn't that be even more effective?
Nice, thanks for the vids. I will be trying something like this soon for some small parts. I have perfected a foam and green sand method I use for my larger parts which I use. Thanks again.
So I take it the plaster is porous, and when the vacuum in the chamber is reached it will pull air out of the investment pores. This will in turn suck the molten metal into the mold forcing the metal onto the investment details?
That's exactly right. I added a quote in there from John Campbell... I can't remember if it was in the quote or not, but he does say even a moderate vacuum can persuade aluminium into a section only 0.5mm - which is pretty darn small : ) So with proper (porous) investment and a simple vacuum set up like this, you can cast jewellery or any other fine detailed items. It beats paying out thousands.
VegOilGuy That is absolutely incredible. So I take it you can follow this same process with just about any metal, and the only difference being how much vacuum you need to pull? Well so long as the investment can handle the heat of course. Thank you again for the video.
I think the flashing might be related to the crack you can see in the pour hole. I wonder if Stainless steel WITH perforation holes might be more forgiving in terms of the thermal differences between investment material and the SS shell. But, you'd have to change you design a bit to expose the entire casting shell to the vacuum. As an aside, have you thought of using a vacuum reservoir that you prepump and essentially dump the casting chamber into? No risk at all to your pump! :) that being said, excellent job! Doug
Hi. I don't know if it would work but would it be possible to use a large strong steel chamber to 'store' vacuum. Pump down the chamber as much as possible then open a tap and used the stored vacuum to evacuate the chamber. This would save you having to pump down when you have molten metal.
I toyed with a very similar idea. I considered using a sealed PVC barrel, placing this under vacuum, the connecting this to the flask.. so by releasing the pressure within the barrel air has to be pull from the flask, ergo vacuum. Thankfully this pump set up was MUCH simpler and made the job easier.
Watched this a few times, as my vacuum chamber is woefully unsuited to vacuum casting, and this looks liek a wonderfuly affordable solution. One thing has sprang to mind that I don't think you've changed in recent videos. Where you're using a silicone gasket to provide the seal, then placing the flask onto it, once sufficiently cooled down as to not pose a melty risk. Why not use a fire brick with a hole through it to match on top of the silicone gasket, and place the flasks on to the brick, that way you'd not have to wait ages and reduce the temp of the flask before pouring? Like, you could surround the non touching edges of the brick with more silicone if you're worried about reduction in suction to the hole too? :)
Thanks David. Believe me, it works well. You see it in all my Lost PLA videos. Actually I don't wait. It all happens fairly quickly. Once poured, it's normally just a couple of minutes for the metal to set enough for me to move the flask on to, you guessed it, a fire brick. Then a few minutes later, it's into the bucket. The silicone pad does get scarred with a "ring" impression, but this happens each time... so it always seals and never damages the silicone enough to cause issue : )
@@vogman Ah, cool! So you're taking the flask nearly straight from the kiln and onto the silicone pad :D I'm sold haha I'll make a new lid for mine from perspex sheet just for this then! Just need to work out what the bits are called for the valve/gauge setup to solder together haha Thanks very much dude, you're a source of inspiration ^_^
soon I will start experimenting with a vacuum casting machine , totaly of my own design as I need it to be able to handle minimum 3 feet long flasks. the problem so far is where to find a gasket who kan handle minimum 650 degrees celsius
Nice work on the home made vac unit and the results.
I cast Sterling Silver jewellery with a Kerr vac unit and if you dont mind here are a few tips.
Reduce the large wax base (button) in your tree and you will have much less wax to burn out. Look at a commercial rubber flask base to see what I mean, the button is usually part of the rubber flask base so you may wish to improvise something similar to reduce the excess wax.
Steam de-waxing works well, keeps the wax of your furnace and re-hydrates the flask prior to burn out (more steam for wax elimination). A simple rack over boiling water with flask opening downward for about an hour or 2 is sufficient. This will make for a cleaner burn out.
When the wax is fully burnt out of the flask, the flask mouth will be nice and white as all the wax residue has vaporized. try not to exceed the investment max temp as the gypsum binders in the investment will begin to break down. This might be what cased the flash on your coins.
Feel free to message me if you wan some more detailed info.
Thanks Wayne. That's a very generous really and offer. I appreciate that : D
Mr Veg, when I was in high school my metal shop teacher taught us lost wast casting because he did jewelery on the side. He used a centrifuge to get the metal into the mold. I love the vacuum method ,you don't have to have a mold flying around along with the molten metal. That is great detail. I remember him showing us a bee he had cast and it had the fine hairs on the body of the bee. Great video! I truly appreciate the knowledge that gets passed around on the internet. I am impressed. Thanks!
Thanks Mike. I agree, one of the great things about RUclips is the information that's shared. I learn so much from people writing in to me and sharing their knowledge. In turn I pass it on here. It's invaluable : )
I know you posted this a while ago, and I'm unsure if you still use it, but if you do, one thing that I think would benefit you, is add a tank in between your pump and your chamber.
While your metal is heating, you can draw a vacuum on the tank, pour your cast, and flip a ball valve to pull a vacuum on your chamber from the tank and then keep pumping to maintain. Youd get an instant draw that youd then maintain. Minimal heat loss from the pour.
This. This is the proper way to pull a vacuum on anything that could introduce process materials into the pump. This is the proper way to pull a big volume into vacuum rapidly such as when doing sheet vacuum forming.
You can use your heat sensitive vacuum pump if you vacuum an air tank, then attach the tank to the mold install a shutoff valve for a quick vacuum pulling the metal in using only negative pressure from an air tank thus the vacuum pump will be safe and totally away from any and all heat while the hot liquid metal begins to be pulled in the mold much faster and more efficiently. Thanks for all your inspirational videos. Keep them coming!
Thanks Daniel : )
Thank you SOOO much!!! I have seen people from Men at Arms Reforged and a couple other videos where they have soo much to say and do, that they mention what they're doing in such an off hand way that it literally explains nothing!!! "'We pour the liquid metal into the mold while sitting on the vacuum chamber then it'll go into quench..."' it raised soo many questions that I've been looking for answers to for almost a year now!!! And poof in one video you hit them all!!! Thank you!!!
Thanks very much. You're very kind.
I'm just an ordinary guy with varied interests. As I explore and learn, I like to share my experiences.
I hope you have the chance to look over some of my other videos : )
@@vogman I've watched several of your videos!!! My 3 favorite are the Mehrunes Razor, the Viking Axe challenge (personallyI think yours turned out better than the other 2 guys) and the vacuum chamber... I had actually already seen the video for pvc hand pump you used to designe your pump. I plan on making a vacuum chamber based on your design!!! Thanks
Many thanks. You're clearly interested in Wax... have you tried lost PLA? You'll see that's the subject of my last few videos. It's totally amazed me.
@@vogman i have not gotten to the lost pla video yet... im currently studying your electric furnace videos... my first furnace is a perlite and sodium silicate ram up in a metal can with a Satanite refractory coating and a propane burner.
Thanks for the incredible knowledge. It's taken me ages to find out exactly how the vacuum casting process works,but now after explaining how the investment plaster is pourous, it all makes sense!!
Nice results indeed. For drawing a vacuum during the pour most effectively, without ever putting any expensive pumps in the line of danger, the simplest setup is to have a vacuum 'reservoir'. Just pull a tank empty with your pump, and connect it via a valve to your flask, then open that valve directly after the pour. That only gives you a short burst of vacuum that is quickly reduced; but thats all it takes. Once you draw the metal into the detail, there isnt anything forcing it back out again. Its more important that you get a strong effect going quickly, so it can do its thing before any of the detail solidifies, than the length of the pull. Your chamber would do as such a reservoir; its just that you are better off placing your flask over its vacuum release valve, than on top of it without a valve. Thats all theory though; never made any such detailed casts myself i should add!
Interesting suggestions. Thanks : )
Perhaps use some plastic plumbing pipe as a vacuum accumulator? Or an old welding gas tank that's aged out of pressure service? You could use your nice vacuum pump to pull the accumulators down, then isolate it and use the vacuum you built up for casting.
Thanks for the suggestions : )
Robert Szasz That is a very smart tip. I’m going to use that.
Robert I worked in a prototype shop and we did vacuum forming on pvc plastic. Our vacuum frame had a big tank that we pumped down and then was released. We only had a couple of seconds for the soften plastic to form to the mold before it would reharden. But that was a great suggestion!
This, I would go with the welding tank, and black gas line and a ball valve. as a bonus the larger the tank the longer it can apply vacuum, IE you could in theory open the valve, and then pour, and have the vacuum be applied through the entire pour till it froze.
Nothing wrong with rewatching RUclips uploads... if you need that stuff that can spark your inspiration. Thank you.🤜🏼🤛🏼😎🍀🍀🍀🇦🇺
I appreciate that! Re-watch away 😁😁😁😁
Preheat the silicone mold at the same temperature of the monlten wax for better result.
Who cares if the camera work leaves to be desired, the channel is brilliant!
No... no champion camerawork here : D
That artifact or flaw was caused by adding the vacuum after the metal was poured. The metal filled the mold.....mostly. The very surface or skin of the metal started to solidify. When you added the vacuum, it filled the mold all the way but it couldn't cover or "erase" that first edge.
Great video!
About 25 years ago, I used three old helium bottles as a vacuum reservoir. Pumped down the bottles ahead of time, and then opened a spigot to apply the vacuum as I poured 14K gold into the mold. Worked great for casting a wedding ring.
Excellent use of initiative for a perfect situation. Well done : )
You should try adding a valve between your vacuum box and where the casting is placed. Then you draw a vacuum in the box and then place the casting on top of the vacuum pad and them turn the valve allowing the air in the casting to flow into the vacuum box.
You could use your round vacuum box for this. I would create a little support stand to hold that silicone pad and run a brass fitting (hose fitting) into the silicone pad and do the same to the plexiglas/acrylic top of the vacuum chamber - then run a line from the silicone pad to the vacuum chamber (the valve would be placed on this line). You don't wan't to fill the chamber with stuff this time, you want it empty. Draw a vacuum as high as possible (you can use your good pump for this b/c it's drawing room temp air) and keep the vacuum running up until you pour.
Then at pour time, shut off the vacuum, pour the casting & place on the new holder and then open the valve and the vacuum chamber will pull all the air from the casting into the chamber and you don't need to worry about pumping fast.
You could also do the same with an old propane tank instead of a vacuum chamber. Maybe draw 50% vacuum (the larger the tank, the better) and then crack the valve to pull air from the casting.
Another way to do this would be to add a little water to a propane tank, heat it with the valve open until it steam exits. Remove from heat & close the valve. Allow to cool. You now have vacuum inside the tank. Connect hose/tube to casting holder & open valve once poured.
I love this idea. Thanks! :D
Another way of getting good wax parts is to preheat the mold to above the wax's melting point, pour the wax, then degas in a vacuum chamber.
I once had a problem with my car door. I was able to cast a new part myself and fix the problem.. Awesome!!!
Nice work! That's exactly the sort of thing I like to hear. It's amazing the stuff you can do at home with casting 👍
Very informative! I was wondering how the vacuum affected the metal until you mentioned the porous investment
I have been racking my brain 🧠 for ever re this process, thanks for doing this. My plaster molds and castings are going to improve drastically.
Glad to help
I just ran across your video and it's great. Thankyou for sharing your skills with us. Have you seen the you tube videos on making a vacuum pump from a fridge compressor? I just finished building one for bead making, with glass. I used a coil of copper pipe just as it came from the store with an old computer fan blowing air through it. It works great and mostly free. I'm looking forward to exploring the rest of your videos. Keep well and God bless.
Wow - what tremendous results! The close-ups are evidence enough that it´s well worth using both dedicated products such as investment plaster and proper wax as well as a vacuum chamber. Now that you´ve effectively removed the "cost" obstacle from the latter I suspect that many of us will be improving our game after seeing this compelling video.
That's exactly what I'm about. When your budget is low but your ideas are lofty, life can sometimes get you down. But if you can find a way that gets you pretty darn close without breaking the bank, well, that's what floats my boat. Then sharing that idea so others can benefit launches said boat. Gosh I'm feeling nautical here : )
But yes, good wax and good investment plaster are two things that can't really be bettered (well, not so far).
So started off watching one video, then one more and so on....good at explaining and goes into enough detail to make sense.
Sometimes wish i had a job and i could afford cool things
Something to cool the air coming from the chamber would both protect the pump and increase performance. With your setup, filling the box with ice packs might do the job.
Good suggestion, but are you aware what happens to water in a vacuum chamber? It boils... I don't know whether the hand point could generate sufficient pressure for that though.
In truth I had no issues at all. I'll probably look at that in more detail another time, but everything came out the other side just fine :)
Water near the freezing point needs more vacuum than I expect you're pulling on the plaster mold before it boils. I was also thinking sealed ice packs, not bare ice.
It could well help... but I didn't witness any reason to even try in honesty. The pump was unharmed. The paint inside the vacuum chamber didn't "brown" with heat. The plastic hose didn't melt. In short, there wasn't the heat that I expected there would be : )
VegOilGuy if you’re home made pump wasn’t getting hot enough to melt, I doubt you’re professional vacuum pump would either. As long as there’s a few feet of hose in line there shouldn’t be a problem, If there is a connection pipe will melt and save your pump.
Good job 👍🏻 my only problem with is the writing is so small and quick I can’t read it before it goes away. Casting came out great though! Have you tried regular plaster of Paris mixed with some play sand? Makes it stronger to burn out the wax or pla
I haven't experimented with PoP and a vacuum yet, no. I believe it's not porous. But with the correct additives who knows what could be cheaply achieved : )
If you have a vacuum pump that can't take heat, perhaps a coil tubing and a fan or bucket of water could reduce the heat enough for your pump. Nice video, thanks for sharing.
for cheap vacuum pumps check with old mechanic shops, years ago AC work was done with a set of manifold gauges and a separate vac pump. But 20 years ago the epa began required the used of reclaiming machines first for R-12 then for 134A. so the old stand alone pumps have been setting on the shelf for decades primarily being in the way. Now that R-12 is phased out I see the re claimers for it fairly often for prices ranging from free to $100. Last I heard they are going to change refrigerants again, which will likely create a whole new glut of old machines.
I know this vid is almost 3 years old but like to add, those artifacts are likely from fractures in the investment plaster during burnout.
You can try adding graphite to the plaster and/or talcum powder. Keep in mind that talcum powder will add more porosity to the plaster, so use it sparingly.
Your videos are amazing! Easily one of the best DIY/casting channels out there
You're very kind, thanks : )
Your making great progress. Few tweaks like properly weighing plaster mixture, and completely drying and heating it much more slowly will help(chemicaly bound water breaking down can also produce enough expansion to crack mould if you don't go slow enough. Also look into ceramic shell casting materials. For your wax using a better silicon you can preheat the mold to be as hot as the wax.
Many thanks : )
Aaaaaaaaaamazing technique, with a domestic and craftmanship materials and technique.
I made a vacuum pump from an old fridge compressor 👍👍👍👍👍👏👏works well for sealing veggie jars too 👍Cheers
Try using a cnc mold. You can machine the wax to a very high degree of detail. Additionally add a valve between your mold and the vacuum chamber. This way you can draw a vacuum into the chamber prior to pouring. When you pour you can open the valve and it will draw in fast and stronger than starting the mechanical or electric vac pump, which needs to draw the air out of the plenum. Essentially your macdonald cups are just reducing your plenum size. The larger the plenum, the longer you can maintain your high vacuum draw on releasing the valve.
Very nice job! Fun seeing the improvement from your earlier coins!
It's hard to get much worse ; )
Very nice VOG, very nice!
Many thanks. I'm pleased with the set up.
i am very impressed, i was wondering how to make a cheap vaccum casting setup, thanks alot, i learned alot
Pleased to help 😁
You can try finding the leak with a sponge and some soapy water, like when you try to find the leak in a tire. (Of course you should pump air ínto the chamber so the bubbles will form on the outside)
That's a good suggestion.
Well done Geoff another great video through the whole video I was asking myself how is the vacuume transfered to the plaster and you waited to the near end to tell me. Great result..
Thanks Luke. One of the problems with doing anything like this is I know why I'm doing it and what I expect to happen. I always try to take the stand that the viewer doesn't and offer explanation. I often worry in case this is a little over-the-top, but messages like yours make me thankful that I did what I did. So thanks for the reassurance : )
Im surprised your not already but You're gonna be huge on youtube m8 , mark my words . Your content is vastly better than most in my opinion
That's very kind but I have my doubts. I'm unwilling to pour molten metal into a large fruit or run over an expensive cell phone with my car, which means I don't have mass appeal. But I'll stick to doing what I do 😁😁😁
You keep doing you m8 . Im in north yorkshire uk we sont like all that immature running over phones stuff . Knowledge is key 🔑 👌 💯
Also its thanks to you im now starting to make my own rings , once i get good at cheaper metals then ill move on to making a gold one and so on . You are a huge part in changing my life , and many others . Keep doing what you are doing bro . If im successful i wont forget
Ah, those wonderful straight-talking Yorkshire folk. 😁👍👍👍
You've got the right idea. I'm still doing exactly the same. I started with scrap metal - which will never get you perfect quality - then moved on to bronze ingots. I've dabbled with a little silver, but it's expensive 😀
You could probably make a heat shield inside your vacuum chamber for existing hot air alil heatsink .those extra hanger s are from casting mold it cracked alil.
Well done. See what sticking to it does. You've come a long way in a very short time.
Oh and CONGRATULATIONS on 10K!!!
Thank you good sir. You're a gent!
One of my many annoying qualities is that I don't like things beating me. If I know something is possible, it eats at me until I manage it. At which point it then generally loses interest for me (yet another annoying quality).
I'm the same way. Weird. Don't know to many like me ! It's kinda a lonely path.
Incredible video, just starting my journey
print negative mold out of ABS, then acetone gas the print to get rid of those print lines. Or you can paint over the print lines a few layers
This was exactly the video I've been looking for to do some metal casting without spending a ton of money. You legend!
That's the plan my friend 😁
Well done you sound quite excited about it can't wait for the challenge to start.
Messing about with dangerously hot metals with a couple of mates... what could be better : )
Cover the whole outside of vacuum chamber with silicone and apply vacuum for 4 minutes then one more layer and let it cure.
Could probably use latex paint or something that is watertight and flexible when cured.
Edit: great casting result 😀
Very impressive details
Very good suggestion : )
Wow, great results, this method rocks!!
Using a vacuum isn't my method really... I just did what the experts do, but this cheap version makes it accessible to guys on a lower budget. Doing that always gives me a buzz.
We had some pretty good luck pouring pewter coins in a split mold carved out of soapstone with a small CNC milling machine. We made the mold, and a friend poured around 100 coins with it as I remember.
Excellent : )
Inspirational stuff Geoff. Good quality video and a calm and informative narration, mixed with a bit of humor makes your content very much worth the time. Thank you.
Thanks Andrew. You're very kind : )
All in all ,well done ,you got my brain engaged
That's great to hear : )
I stole the compressor out of a refrigerator to use as a vacuum pump.
My castings are great, but my food... not so much.
I strongly admire your priorities ; )
@@vogman would i be able to use a small air compressor instead of the hand pump? maybe something like this? www.amazon.com/Campbell-Hausfeld-FP209499-Gallon-Compressor/dp/B002O15NRS/ref=sr_1_7?keywords=air+compressor&qid=1577601182&s=hi&sr=1-7
I bought a compressor which cost me 70 quid.
Excellent results.
Thanks Kelley : )
Try breaking the vacuum casted metal in half and look at the grain structure. I've heard if you do it in vacuum, there isn't any crystallization, the whole piece becomes a single crystal.
Awesome! This answered so many questions I had and some I didn't know about
Lol saw this and got super excited like I’d love this video. Clicked on it and I’ve liked it already so I’ve had this same thought before and forgot lmaooo
Holy hell Geoff there friggen perfect. That investment plaster is awesome . It’s a shame your not in Australia as I can get those wax chips from my work for nuthin but we only have yellow and red no blue . I definitely know not to challenge you in a coin reproduction 😳😲. Great stuff matey 🤙🏻👍🏻😁.
It's incredible. I was scared people wouldn't get the idea and would just see the ugly lines... but to me it didn't matter what I was casting, I just wanted some obvious detail and a means to replicate it easily. I think I've found it.
You have access to wax products? Mate, you've got to try lost wax. In terms of accuracy I believe it's arguably the best form of casting. It's possible to create things that couldn't be done in sand and only a machine could produce in foam.
You'll love it!
Bloody brilliant! So hey I’m in Australia, and would love to get some wax chips in my hands for my electric lost wax attempts
I already knew I'd see you here😎
you truly a gem of casting.
That's very kind : )
Nice video. If you used an old fire extinguisher or gas bottle (make sure to flood it to drive out any gas) or even demijohns you could make a "vacuum reservoir" between the pump and the chamber to give an original hit of vacuum before you get pumping.I've heard of old fridge pumps being used to make vacuum pumps and 3" copper pipe and a foot pump being used to make a pressurised wax injector - not that I've made any of these myself.
Nice input. Thanks : D
Toward the beginning of the video you mentioned that the vaccum pump can't handle heat. Couldn't you plumb the vacuum through some coils of copper tubing and submerge the copper in water or even ice water to keep any heat from damaging the vacuum pump?
Very nice video.
I would like to ask how the liquid metal inside the plaster is affected by the vacuum under the plaster since there is no communication between them?
Not sure how vacuum leaks are supposed to be checked but I work as a pug mill operator making ceramic tile. We hold a lit candle up to check for vacuum leaks. The flame will get sucked right into the leak without blowing the candle out. Not sure how big the leak needs to be to be clearly visible though.
Ive never tried it and have never seen anyone else do it but i wonder if a vibrator or tapping the sides of the casting wouldnt get rid of air pockets?
It's unlikely it would work. Ideally the metal should set almost instantly. The longer it remains liquid, the more it will attract porosity, etc. But good thinking 😁👍
Question? With the vacuum pump, could you use a copper pipe 12 inches long and a couple of reusable ice packs- cooling the air prior to the camber?
the cups in the vaccumchamber does reduce the time in wish the vacuum diosipates through the leak theres less buffer
Have you looked into centrifugal investment casting? Jewelers use that technique for casting intricate jewelry. The g-force from the spinning centrifuge pulls the liquid metal into the mold.
Hi Peter. My original plan was to build a centrifugal system... but they take up a fair amount of space and you've got to balance them very well for safety. I found this vacuum set up MUCH easier with excellent result. Safer too... amateur builds spinning molten metal at hundreds RPM is a terrifying thought ; )
Checking comments to see if this was already addressed, I did it in high school, super simple setup and honestly I think it is a better faster option, also used displacement to make sure I didn't waste too much metal. I also cast scorpions and other insects.
@@vogman I used to cast for a jewelry shop, and I used a centrifugal casting machine with a built-in electric furnace. It was fast and reliable, and easy to use.
I use centrifugal casting because you can just melt the metal in place and let it go. The key is safety. I built a shield around mine with a lid so as soon as the metal is melted I put the lid on and duck behind my shield and let it go.. Picking up a crucible full of molten metal is much more dangerous in my view.
Very well done.
Many thanks : )
great vid.......love your dry humour & simple instructions
Thanks : )
Great tutorial on lost wax casting. Have you considered a way to create the vacuum in your box before the flask is placed on the silicone pad then, after pouring the molten metal open a valve and “dump” the vacuum into the flask? You would have to construct a stand on the top of the box with another valve, but I am sure you could come up with a clever solution. Doing the vacuum as a “dump” would have the same effect on the flask as you were wanting to have by adding the containers of waste plaster: faster application of vacuum force.
It is something I've considered, but I think I prefer the easy control of a pump : )
@@vogman I'm trying to get into stainless steel casting for objects about 3-6 inches in length and width. Can you offer advice particularly with a machine that reaches that high temp?
Wouldve ran your good vacuum pump and added a chamber inline to prevent sucking in any heat. Could’ve gone about that a few ways including a mini radiator with fan blowing through or water cooling a copper loop. Either way cooling the air wouldn’t have been too difficult. Alternatively running 15-20ft of vacuum hose passing through a bucket of water may have been enough.
To locate your leak in your vaccum box try pressurising in it then using some soapy water. It might work. if air cant escape then it shouldn't get in. Great video by the way.
You probably already know about the use of a casting well that uses centripetal force to achieve the same effect of drawing the molten metal into your mold. It has the advantage of being able to keep your mold at high temp while casting. I think the extra flash or fins may be from defects in the investment plaster due to shrinkage of the plaster. Anyhow, I found your ingenuity to be great and it produced a nice result. Thanks for the video!
I've been watching Alec Steele for a while and this popped up in the similar videos lists. I'm glad it did, very entertaining and great explanation of the whole process. Thanks so much for sharing. I'm looking forward to watching more.
Thanks very much : )
I'm afraid Alec and I are in a different league. Whilst he has every tool available and an extremely large budget to play with, I have basic tools (that most DIYers have) and barely any budget. So I strive to be innovative, finding cheaper but equally good ways.
If you look at my more recent casting videos, you'll see this budget casting vac really does work. If you look at yesterday's video, I saved a few hundred pounds by building a vibration tumbler for £20.
If you can cope with that, then you may enjoy some of my content. Feel free to let me know : D
@@vogman Thanks for the reply. You may not have Alec's budget but your results are great. Its very encouraging as I'm also on a low budget and want to do so many things in my little workshop, a tumbler is a project I'm also collecting parts for. I'll be watching more of your videos in the future, thanks for sharing
Saving this to try later. Brilliant video
Nice clean castings for sure!
Many thanks : )
Your videos are awesome man! I'm so glad I found your channel, your work has inspired me to finally start metalworking, something I've wanted to do for the last 20 years but never been confident enough to invest in. I finally have my furnace and kiln set up, and I just need to set up a vacuum system and I'll be ready for my first trial run. Don't have to work for another 10 days, so I might get on down to the Home Depot this weekend...
You are amazing man
Can you tell my wife that please : )
@@vogman 😂
I like this. I started with an old Vinyl Album Turntable set up with some rubber bands-you spun it up, did your Investment and casting then released it and it spun like a Centrifuge. My latest project is an electric motor from either a lawn mower or a kids street gokart but this pump you built looks a bit more reasonable to do. I can use one of those motor to build a homemade grinding wheel instead. :)
Mark, never let me discourage you from mechanical chaos. Have you not seen my lawnmower? ruclips.net/video/-ezH92dfZqQ/видео.html
You're a brave man. I initially toyed with the idea of building a centrifuge but chickened out. The idea of molten metal spinning violently at high speed filled me firstly with excitement and then more sensibly with panic.
This pump method is incredibly easy (I've demoed the pump in another video if that helps) and the results are astonishing. It's quite astounding how little vacuum is needed, and that's got to be safer than spinning metal... though not as exciting : )
Absolutely beautiful castings.
Thanks Magnus : )
I've seen several diy vacuum pumps using fridge pumps. I've also seen glass demijohns with a couple of valves in between the pump and the chamber to act as a store of vacuum (can you store a vacuum?) when the actual pump wasn't fast enough to drop the pressure straight away.
sei un grande! many, many thanks
Great stuff. Well explained and in laymans terms that even a spanner twirler like me can understand. I'm about to venture into the new world (for me) of silicon mold casting and I have no doubt that something like your vacuum chamber will improve the outcome(s) of the models I aim to produce. Cheers....You have a new subscriber from the land of convicts, cold beer and hot pies!
It's great to have you here Mark. I agree that a vacuum chamber is a very useful tool for silicone moulding. If you check out the video I made last week (Miniature Skulls) you'll see I made a simple silicone mould for that using my vacuum chamber. If you have any questions, feel free to drop me a line mate : )
Great video full of useful and helpful info!
Quick Question..
is there any way you can make this to withstand heat from having the plaster pulled from a kiln???
You had some cracks in the plaster. The sharp edges on the details are probably from the cracks
This happens because of the thin steel plaster container maybe?
I liked it, it's very informative
Glad you liked it!
Do you ever paint your wax patterns with a surfactant? It can prevent bubbles in your cast.
Hi Kirk. That's not something I've done yet. Sounds interesting : )
Just 're-watched' this and had another idea. Old 13kg propane cylinders are freely available and easy to clean out any residual gas.
How about preparing a cylinder of vacuum, harder than you need, then using it as a reservoir. It would enable more control of the draw-down and be constant rather than pulsed.
It might be worth trying 😁
or just put a much bigger pouring cup on your mould to increase the pressure so the mould fills fully (and maybee increase the temperature of the metal if the mould is'nt filling) and to provide a source of molten metal while the casting freezes eliminating shrinkage faults
Great video! So the mold got vacuum sucked through that tiny hole in your chamber lit? Only air flowing through the bottom of the mold. Who would have thought...
I thought about perforating that metal pipe you bought and hanging it in a bigger hole through your chamber lit. Wouldn't that be even more effective?
Dude this is so awesome! Looks like a ton of fun
It is fun : D
Nice, thanks for the vids. I will be trying something like this soon for some small parts. I have perfected a foam and green sand method I use for my larger parts which I use.
Thanks again.
Always good to hear from a fellow enthusiast.
So I take it the plaster is porous, and when the vacuum in the chamber is reached it will pull air out of the investment pores. This will in turn suck the molten metal into the mold forcing the metal onto the investment details?
That's exactly right. I added a quote in there from John Campbell... I can't remember if it was in the quote or not, but he does say even a moderate vacuum can persuade aluminium into a section only 0.5mm - which is pretty darn small : )
So with proper (porous) investment and a simple vacuum set up like this, you can cast jewellery or any other fine detailed items.
It beats paying out thousands.
VegOilGuy That is absolutely incredible. So I take it you can follow this same process with just about any metal, and the only difference being how much vacuum you need to pull? Well so long as the investment can handle the heat of course. Thank you again for the video.
Yes, any metal. The good news is the amount of vacuum required isn't that great so even a simple home made pump like this can do it : )
I think the flashing might be related to the crack you can see in the pour hole. I wonder if Stainless steel WITH perforation holes might be more forgiving in terms of the thermal differences between investment material and the SS shell. But, you'd have to change you design a bit to expose the entire casting shell to the vacuum. As an aside, have you thought of using a vacuum reservoir that you prepump and essentially dump the casting chamber into? No risk at all to your pump! :) that being said, excellent job! Doug
Hi. I don't know if it would work but would it be possible to use a large strong steel chamber to 'store' vacuum. Pump down the chamber as much as possible then open a tap and used the stored vacuum to evacuate the chamber. This would save you having to pump down when you have molten metal.
I toyed with a very similar idea. I considered using a sealed PVC barrel, placing this under vacuum, the connecting this to the flask.. so by releasing the pressure within the barrel air has to be pull from the flask, ergo vacuum. Thankfully this pump set up was MUCH simpler and made the job easier.
Compared to lost PLA, how long do you cook the plaster mould? In my head, the wax shouldn't take so long?
ooo i'm amazed that looks flawless
It works very well : )
Maybe pre-heat the silicone mold to prevent filling lines? Silicone should be good for well over the wax melting point.
Watched this a few times, as my vacuum chamber is woefully unsuited to vacuum casting, and this looks liek a wonderfuly affordable solution. One thing has sprang to mind that I don't think you've changed in recent videos. Where you're using a silicone gasket to provide the seal, then placing the flask onto it, once sufficiently cooled down as to not pose a melty risk. Why not use a fire brick with a hole through it to match on top of the silicone gasket, and place the flasks on to the brick, that way you'd not have to wait ages and reduce the temp of the flask before pouring? Like, you could surround the non touching edges of the brick with more silicone if you're worried about reduction in suction to the hole too? :)
Thanks David. Believe me, it works well. You see it in all my Lost PLA videos.
Actually I don't wait. It all happens fairly quickly. Once poured, it's normally just a couple of minutes for the metal to set enough for me to move the flask on to, you guessed it, a fire brick. Then a few minutes later, it's into the bucket. The silicone pad does get scarred with a "ring" impression, but this happens each time... so it always seals and never damages the silicone enough to cause issue : )
@@vogman Ah, cool! So you're taking the flask nearly straight from the kiln and onto the silicone pad :D I'm sold haha I'll make a new lid for mine from perspex sheet just for this then! Just need to work out what the bits are called for the valve/gauge setup to solder together haha
Thanks very much dude, you're a source of inspiration ^_^
Cool laid back video, thanks
Many thanks : )
have you ever thought of useing an old refridgerator compressor to achive the vacuum ?? you can get them for free withot any problem
You're the second person to suggest that to me. I've no doubt you're right : )
soon I will start experimenting with a vacuum casting machine , totaly of my own design as I need it to be able to handle minimum 3 feet long flasks. the problem so far is where to find a gasket who kan handle minimum 650 degrees celsius
not shore a fridge pump will move enough volume. intake side of shop compressor does. some filter/baffle box inline and your set
Hello, i need to pour in a 600/650 Celsius flask. What kind of material should i put in the bottom of the flask?
Good work. I’ve been watching you since the start. Your getting good! Well done :)
Thanks David. Persistence pays off in the end : )