You rock, dear brother!!!! Thank you, for your humbleness, in posting your failed attempt! You have probably helped many viewers, from making the same mistake.
By now you know how many scoops of concrete/sand/perlite you need to fill the entire bucket so mixing a "one fill" batch may be a better idea so as not to get the different qualities in each level, which also may make it more susceptible to cracking. I am also certain you have already thought of this since this failure. Thanks for the watch, I'm enjoying. ciao.
I could give that a try, if I mix it in my wheelbarrow. Mixing more than what I've been doing in the bucket would be difficult. Thanks for the suggestion. Glad you are enjoys the videos. Thanks for taking the time to comment. :-)
Let's say it together : I told you so... one more time, I told you so... But we all love and support you and eager to watch your next video. You are a nice person.
Enjoy your inventive spirit. I read a suggestion somewhere for smallish projects; to gauge how much concrete you might need, fill the cavity with a volume of sawdust (or ?) and then use that volume to estimate concrete required. Keep up the good work!
Remember if you never experience failure you aren't pushing the boundaries far enough. If you are going to be doing a lot of concrete mixing you might consider making a small mixer. Then you can mix all of the batch at one time and everything will be consistent. While your batch may have been too dry the problem may have been that the components weren't adequately mixed. The process of mixing grinds all of the components together so that every particle is fully wetted. This is particularly important with perlite since its surface is very good at trapping air. It is essentially glass foam. A good mixing will likely take 15 to 20 minutes. Also, as was said by Copenhagen King, motor oil is commonly used as a release agent for concrete. You might also use caster bean oil.
I'm super intrigued about building a rocket stove & I was wondering about the perlite option to lighten the weight. Thanks for including the videos where things don't go perfectly- it's helpful to learn those things too, before taking on a project.
I did finally weigh both concrete stoves, with and without perlite. I can't recall exactly, but I think the concrete-only stove weighed between 75 and 80 pounds and the perlite version was 15-20 pounds lighter. I remember being shocked by how much weight the perlite helped shed from the stove. AND, it provides insulation value too. Thanks for watching.
Thanks for sharing the failures, knowing what went wrong is good for us knowing how not making the same mistake, in this or any other project. Appreciate it!
I've experimented quite a bit with perlite concrete mixtures. Perlite significantly weakens castings, especially when moisture is present. The cardboard liners you used in earlier videos gave better de-moulding than anything I have tried and I will definitely use carboard in any future projects. I was fearful you might follow the advice about using demould waxes, knowing from bitter experience that nothing will come close to the easy de-mould you had with the cardboard. Good work, thanks for sharing.
Thank you for the feedback. I concur on the perlite. I’ve considered putting a seam in the pour with a piece of chip board, to force the expansion crack. I’ve had success strapping a cracked stove with steel pallet straps. I definitely think I’d go back to the cardboard for my next casting. Thank you for watching.
@@GreenShortzDIY for what it's worth, I think cracks forming on heating release stresses inherent in the casting and, if the cracked part is bonded back together it becomes stronger than it was before. I've bonded cracked parts back together using a slurry of talc in sodium silicate and the reformed pieces didn't crack again over prolonged use in heat risers etc. I'm considering casting future heat riser tubes as wedge shaped blocks that I bond together afterwards to make a tube, the idea being that there would be none of the stress inherent in a closed circle.
Glad to see the mask. Perlite dust is terrible for the lungs as well, it is essentially expanded glass. Nice series on these concrete rocket stoves, I am inspired to try making one.
I like your positiveness, thank you for teaching how to build a rocket stove and the message behind that we can learn from our mistakes without giving up. thanks
I've had similar results with cooking spray. I've had great results with a layer of paste wax (slather it on, no need to buff it on a stove) and warm your plastic with a hair dryer after to get it to release easily. I've used this method for ornamental cement work. I also found that fumed silica made the cement lighter, a bit stronger, and much smoother, but don't know if it would be useful as an ultra fine lightweight aggregate for stoves.
great videos! I came upon some empty beer kegs recently and realized they would make a great shell for the rocket stove. You wouldn't need to worry so much about outside strength, allowing you to increase insulating value of liner. currently a 26lb . stainless steel keg is worth $9.10 scrap value. you should be able to pick one up for under $20 thanks again for videos
I’m no concrete expert or anything, but I did pour a lot of it during my 20+ years of bridge construction. We had a saying. If you’re going to pour concrete, the concrete MUST pour! If you pick it up and it’s dusty, it’s too dry.
Well said !!! I have poured a lot of concrete ... and the worst thing that can happen after removing the formwork is finding large patches of concrete missing because the mix was too dry ... 😵💫😵💫😵💫
Remember: The concrete provides the strength. The perlite provides the insulation. The more perlite you add the weaker the mix will be. The less perlite the stronger the mix, but the less insulation quality. I would much prefer, if it were mine, to make the mix stronger and forgo some of the insulating quality. A stove that is stronger, but doesn't insulate as well, is better than a very well insulated stove that falls apart after a couple uses, if it lasts that long.
Thanks Ken. I agree with your preference. The rocket stove I made with the crack resistant concrete and an armature has not cracked. In my mind it performs just as well as the perlite insulated version. I’m an experimenter, of course, so I like to try different applications. Thanks for the feedback. Thanks for watching.
Few things I've noticed from my experience: cardboard liners all the way, I think the 1st layer needed to be tampered better bc the perlite made air pockets on my fire brick too, and the fresh cement in mold is brittle until light grey appears. I didn't have good luck with Pam for release agent either. Wait until concrete shrinks with it upside down on blocks... live and learn right? Thx for another lesson
Well the Falcons have been know to blow a solid lead. :-) you just reminded me I need to link your channel. Forgot to add that in the description. Thanks for the feedback. Hope you are well.
GreenShortz DIY I'll get a vid of the fire brick I made. I feel extra binder is required to wick moisture held in the perlite/verm... I am impressed how well my pedestal held up under the 80lbs tower and heat. I made a back up that didn't need yet. Should be perfect for an example. Thanks, for everything...
I love what you are doing. I worked for 22 years in a RD dept. The ole saying is two heads Are better than one. Only problem on you tube there are so many unqualified people adding There in put. But that’s ok . I plan to watch this to the end. I love the content as the way you Do your videos. I subscribed!
we used to use diesel as release agent when pouring concrete on wood forms, also have used plastic liner as release aid , I'd suggest using sack crete with the fibers or just go with Georgia clay and straw!
Ha. I’ll take that as a compliment. Lol. The main reason I take the approach I do, is because while I do usually trust my instincts and knowledge, I also know I don’t have all the answers and I want to learn new things myself...even when that means failing. I still post those videos because I think there is still value in the process. To your point, when we see what doesn’t work well, next to what did work just fine, the best path forward is clear. Thanks for letting me be philosophical this morning. :-) Thanks for the feedback, and thanks for watching.
On future pours, I have some ideas that might be helpful. attach a hinge and latch to the bucket, and then slice in down the center into two halves. A day after the pour, you can open up the bucket like a book. My second suggestion is to make the center plug out of a wooden 4x4. Use a table saw to slice it lengthwise in two places so that you have three planks. Make the center one slightly thicker than the other two. Then use a table saw to trim the four corners so you end up with a slightly hexagon shape in the cross-section. A day after the pour, hammer out the center plank, and the other two should come out easily. Another thing that might be worth trying is to make the pours into two sections. Make an inner shell first with a high perlite mix, and after its complete, pour an outer shell with very little perlite for more strength.
Decades ago I tested concrete for an engineer. We were testing on a military base and the specifications call for no more than one inch slump. The test is carried out using a metal mould in the shape of a conical frustum known as a slump cone or Abrams cone, that is open at both ends and has attached handles. The tool typically has an internal diameter of 100 millimetres (3.9 in) at the top and of 200 millimetres (7.9 in) at the bottom with a height of 305 millimetres (12.0 in).The cone is placed on a hard non-absorbent surface. This cone is filled with fresh concrete in THREE stages. Each time, each layer is tamped 25 times with a 2 ft (600 mm)-long bullet-nosed metal rod measuring 5/8 in (16 mm) in diameter.[2] At the end of the third stage, the concrete is struck off flush with the top of the mould. The mould is carefully lifted vertically upwards, so as not to disturb the concrete cone. The concrete then slumps (subsides). The slump of the concrete is measured by measuring the distance from the top of the slumped concrete to the level of the top of the slump cone.[
Your videos are great, and inspirational. I do appreciate the part about learning from your mistakes so I have a better chance to succeed the first time....... I'm also glad that you get compensated for these mistakes, because you earned it. Keep doing what you do man!! I have to admit I did chuckle when you broke out the cooking spray.
I like what you're doing with the rocket stoves, and I'll be the first to tell you that I'm no concrete man per se'. I have worked with it a little down through the years, and I always thought you were supposed to strive for a single pour! And that brings up another aspect to it. It should be a pour, and not a pack, or tamp. At least that would be my approach. I spent 49 years in the house painting business, and I've done everything from fence posts to sump pump sinks, to French drains etc. And the last thing you want to do is pound on green concrete. Even if you dont do obvious appreciable damage, you can hairline it which will come back later as a heat crack. im not sure what would be a better release, but roofing felt comes to mind for me. Seems like it'd be thinner to work with, and should release okay, but that's a guess on my part??? Wax sounds good but how to apply it is my question. Some kind of a grease stick!!!?? I don't know. Hey have fun, I'm enjoying watching. 28 days sure surprized me. But I guess the longer the better. Especially when heat is involved.
I suggest using a mason’s tub for a lot easier mixing. No sharp corners, and shallow rather than deep. Various sizes available, and not expensive. Best quality ones where contractors shop.
Im in capital now, and watch this video with a cigarettes 🚬 and some coffee ☕ in the middle of the night 🌃 makes me feel like im home now. Its fun and its kinda soothing, thanks for the video man, keep doing something like this, something that makes home better and better.
Not enough combiner (Concrete) I think. Maybe 3 parts perlite, 2 parts concrete, & 1 part sand. Plus, use a thicker oil like shortening or Crisco then dusting it with dry concrete or sand. Same idea for baking cakes (butter & flour)
18:58.... "When We FAIL... We TRY AGAIN." You OWN that Statement. "Almost" hint hint- sounds like something you should print out on a Tshirt..... Good Advice. For EVERYONE! God Bless. Nice Video. "HE Doesn't give us all we Want, HE Gives us the Tools and Motivation to Make It Happen..."
After how many minutes of running did it start to crack? Anyway, it's just a nice circular stove. In the world there are many rocket temples because they have burned and have circular columns.
Have you ever thought about using one of these for ambient outdoor heat on cold days like restaurants do with those propane heaters? I was thinking you could take an old well pump tank or something and drill or plasma cut a bunch of small holes in it and attach it on top of the stove in a way that it is solid but easily removed.
I used to do commercial diving and we did underwater concrete pours. It was inevitable to get some concrete in our gloves and after pumping concrete into forms and using our hands to guide the tremmie hose and concrete the other divers laughed at me for constantly using hand lotion on my hands at the end of each day. After a week their hands were dried out and skin cracked all over, my hands were slightly dry but not nearly bad enough for my skin to crack. So personal suggestion if working with concrete and exposed skin wash skin thoroughly then apply liberal amounts of hand lotion. It pays off.
If you make a lot of these then attach the wood blocks to the Outside, wide end, top of the bucket. Then you don't have to try to position them to break it out of the mold bucket. I like to leave a thick throw rug under it, so when it the stove slides out of the mold the fall doesn't break it. I do this with concrete weights as well.
a side note... have you ever tried "Air Crete" would make this portable (though air crete is kinda soft so I have had to trowel on a light mortar mix/stucco on the outside to act as a shell)
I have considered air crete. I just need to learn how to make it. I know Honey Do Carpenter has a foamer design he sells. I've gotten lot's of comments suggesting are crete...will do this at some point. Thanks for the suggestion.
The ratios looked pretty okay, you would have gotten a better result if you had hit it with a cement vibrator when pouring. This would have gotten thing much more evenly distributed. Maybe in the future, mix up some small batches and make little fire bricks with various mixtures and see what ratios and consistencies work the best for your needs. But 110% use a cement vibrator next time. Gets all the air out, homogenizes the mix, and makes your finished product perform waaaaay better. Thanks for sharing the progress with us!
Great vid, thanks! I'm thinking of trying this, but I've built many coffee can size rocket-stoves with holes drilled to allow the wood gas to travel outside the burn-chamber, up, and with more holes at the top allow the gas to go back into the chimney and be reignited in beautiful blue flames. So I'm thinking of adding this feature by attaching a small diameter cardboard tubing stuffed with paper towels. The tubing would horizontally leave the burn chamber, maybe 3 inches, turn at a right angle, then straight up close to the top of the chimney, turn back and connect to the chimney. After the tubes all burn away it should allow the gases to flow through to be reignited. that the plan anyway. Sound crazy?
Sounds like a cool experiment. I say give it a try. That’s how innovation happens. Dyson created his new vacuum after 5000 prototypes. :-) I’d love to know how it turns out.
I suggest you use thick Lard to lubricate the form work rather than spray on olive oil - which just got absorbed where thick Lard would be more durable
From professional MASON. Mix 3:2:1 cement in ONE batch. Calculate volume needed, mix in wheelbarrow with back and forward motion of a regular SHOVEL. ADD one squirt of dishwasher to water. Start mixing with less water than required, add extra water slowly in handful at a time
Line the bucket with plastic cling wrap , that is the easiest sure way to get an effortless release . It's gonna leave a little texture but it's guaranteed not to stick !
Anything the mind can conceive so can it achieve you are proving that and inspiring people .tHANK YOU FOR YOUR TIME AND VIDEO'S. I would like to add a few thought's the parchment paper liner is perfect, the perlite does hold water measuring water each time is as important as the other, longer bolts on the inside would be better and a washer, the outside bolts could be used to release the bucket screw them gently to allow air to escape should help to release.I hope to follow yours and try myself. Again thank you..
Mix the water with the cement and incorporate the perlite after so that all the water will go to the chemical reaction of the concrete hardening and non will be lost in the perlite sponge.
Very good video!!!! It seems that it is better to fail by adding more water than to leave the mixture too dry ... On the other hand ... as I was watching this video..for the part that you sprayed the bucket and the PVC with the cooking oil ... I said to myself ... it's going to be very difficult to get the PVC and the bucket out of the concrete. The cooking spray is simply washed off with the concrete mix ... You better stick with the cardboard approach. I am in the process of making a small forging unit (for melting aluminum) ... and the proportion of my concrete will be 4 parts perlite, 2 parts sand and 1 part Portland cement. That's what I can get at the hardware store. I will use chicken wire to reinforce the concrete. There is a second idea which is to replace Portland cement with plaster of Paris ... what do you think? Thank you, and you have a new subscriber.
Thank you for the feedback. I recommend using the plaster of paris. I’ve got a plaster and perlite forge that has stood up to the heat well. I did an aircrete forge, with portland. It insulates well, but the parts that glow red, crumble once they cool.
Not enough concrete in batch with too much peralite an no beating on sides of mold use air pressure from air gun through bottom hole, make sure wire mesh lines up with cutout on bucket, I've used grease as well as motor oil but you found out about cooking sprays! Tim
I do wanna. I've been thinking about this for a while. I've got a few more versions of the stove I want to build this summer. Will likely try the water heater version late summer or early fall. Thanks for watching.
Watched a few of your videos, and I love the experimental aspect of your projects. Also, you go a long way to involve your commenters into your process, which seems to be exactly what youtube should be all about. Keep up the great content.
Thanks for the suggestion Patrick. I may do the wax paper on the PVC riser form. I want to see if I can get the main body of the rocket stove out with just grease or oil. Thanks for watching.
This is an old video but i'll give you some feedback from our lab. We use WD-40, on our metal molds, but they come apart in two halves. For plastic molds, we wait a minimum of 48 hours (longer is better) punch a hole in the bottom of the mold, and then spray compressed air in to get it to release. a little concrete usually busts off the edges but if you let t cure longer (curing is a chemical process, it doesn't "dry") You can reduce this. Also I'm very interested in how this would perform with a fiber admixture or metal fiber admixture.
Jonah, thank you so much for the excellent feedback and suggestions. I will definitely halve my forms for the next go round. I like the idea of adding fiber as well. Thank you for watching.
Nice project. Saw your first video and this one. I think you don't have enough water and not enough cement. I'll try the project myself but will not use perlite. Instead I'll try to coat the armature wire in aluminum foil (several layers). It deflects heat. I'll just leave area at top and bottom for concrete to connect and make some holes in the foil for connection. Good luck with your next version.
And you already found out but the longer concrete has the ability to remain wet the stronger it will be. Always mix your concrete wet. If your laying stones in , say a stone wall you should mix your mortar /cement a little on the dry side because stone does not absorb water like brick or cement blocks
GreenShortz DIY I'll have to check them out I want to build a rocket stove/chimney that can throw a little heat too . I hope I don't sound like a jerk I enjoy your videos I like when you show your failures too keep up the good work.
A bolt going through the center of the bucket, with the threads coming out the bottom of the bucket, and a knob screwed on will make it easy to simply pull the bucket off after curing.
I'm thinking you could have wrapped your forms in wax paper and tape. The bucket could have been coated in motor oil and had wax paper inserts then add the mixture. So even if it stuck to the paper, that could easily be burned off.
I don't think there is any other video out there as well explained, or watcher oriented" as you're videos are.!! I do like the way you explain everything SO Well.!! I know you've been getting a lot of good comments, on how to improve the "Release process" but I think you should, line the inside of you're bucket with a Thick plastic" it would come out a whole lot easier.!! However, it would need to be removed from the bucket, while the plastic liner could, be peeled off the side of the stove, if let set up over night, the plastic liner will be to hard to get off, and make a melted plastic smell evertime the stove was used.
someone read my mind Georgia clay they use it with straw for chimney bricks there's an old-timer in Savanna that still does it the old way you could make your on bricks to set your stove on.OK, I hear you I think I said enough.GREAT WORK
I too thoroughly enjoyed the experiment. We learn far more by our failures than our incidental successes. This video ... made me subscribe to your channel... Thank you... BTW... in not reducing the weight.... perhaps.... set some kind of handles on each side... to carry the stove to new locations... perhaps 2 people taking a handle?
in your other video, where you used a terracotta flu liner on top of bricks... instead of using PVC as your chimney form, could you use the flu liner (then just leave it in ). maybe notch the flu liner with your angle grinder so it could double as your pot stand offs( fill bottom of bucket with sand to depth of pot standoffs or notch the bucket so they poke through). so in your form the flu liner sits on sand to top of notch(or poke through), then your jug, surrounded by your bucket... mold release... crisco (just something to try) I have played with perlite for a while... best results is when I create the cement/sand/water mix get it all nice and creamy then slowly add perlite until I have the desired consistency (depends on if you want it pourable or packable) also to make it more pourable with a dryer mix they have a product called Flow Control which makes the mix looser before it sets... have only used that when making slabs for a firepit, but it does help...
Thanks for the feedback and suggestions.The flue pipe idea is an interesting one. Also appreciate hearing your technique on mixing in the perlite. Thanks for watching.
Great video man I enjoyed watching it but maybe you should've followed your inclination to take my advice. Oh well still a fun video and a great project. EDIT I didn't want to sound like a know it all buuuut youu did give me the right to an I told you so lol.
Ha! Yes, yes I did. :-) I think I had the mixture too dry. Did you notice? First it was way too wet so I mixed in more dry materials. Would appreciate your thoughts. Thanks for watching.
GreenShortz DIY well I did notice that it was way too dry and in my opinion maybe next time mix all the ingredients forgo the extra perolite and make sure that it has enough moisture in it so you can properly consolidate it that you cqn improve on the next attempt also i noticed the threaded inserts great addition the cooking spray was a good idea too but maybe go for a heavier oil that has a better film streangth such as engine oil. I appreciate your interest in my ideas and greatly enjoy watching them looking forward to your next one 👍 :)
Thanks for the feedback. I was guessing the cooking spray was a little too weak to release well. Would Crisco have the film strength needed? I was trying to go with a food-grade product. But, if you think it really ought be engine oil, I'll go that route. Thanks again.
GreenShortz DIY no problem man and I do believe crisco would work for what you're doing also if you let it cure for 2 days and use the proper ratio the mallet is not going to hurt it one bit keep up the good work man
Hey nice video, man! Really cool! I suggest geopolymers as a material. Better heat and chemical resistance. Or as a fire or heat resistant coating. Fire is not only damaging materials through heat but through very corrosive gaseous substances in the fume. Along with the heat it is a extremely corrosive environment and Portland cement is a rather weak material. I'd say even easier is to just mix perlite with diluted waterglass which gives a interesting refractory like material for coating and insulating the fire chamber. I have so many projects but I have hope that I will find some time soon to make a rocket stove. Have a good!
Funny, but I believe the mix wasn't too dry, you just never compacted the concrete enough. High frequency vibration is recommended for low-water content concrete. Tapping with a piece of lumbar, lol. I use water at a ratio of 0.4:1 water:cement (not concrete) by weight and make some beautiful pavers always. But I use a vibrating table at almost 4000rpm.
apply tin lay of grease on the inside wall & base of bucket same for the pcv pipe outer wall before pouring in the wet concrete , will be easy to remove once the concrete dry
Copenhagen king was right!! not enough sand+cement to hold the perlite together. more water might have helped but you should of mentioned him; at the end of the video. Entertaining and educational non the less👌👍
You sprayed your bolts with the release agent, that's not good for having the Crete mixture to adhere to them. Go back the cardboard you know it works for you with a used bucket. For a release agent to work the surface needs to be pretty pristine.
you could call the concrete company and explained to them that you want to add some kind of flake insulating agent like what you used perlite ask them if they have some kind of like bonding agent it seems that the perlite doesn't bond to concrete they might have some other suggestion for you as far as insulation
Had a BLAST looking through ur vids. Made an attempt at a Rocketstove myself, a coupla years ago. It went south with NO option for north.... Had the measurements, the 1-2-4 bit, all wroooong. :) Still, it was a fun project and i LEARNED alot. So keep it up. Iv got my fingers x´d for ya! Greetings from Sweden!
Nope, you're going to have to either grease the hell out of the inside of the bucket with vaseline or cut the bucket off the mold. It will always crumble if you try to hammer it out. Wait at least a week before you try anything.
Four years late but information doesn't hurt. Maybe you could have salvaged some of the materia that crubled away if your had rewetted it with a spray bottle to give it enough water to complete the chemical reactions. It also might help to ensure concrete doesn't dry too fast, by again spraying it and wrappin it with plastic. Lastly it might be a decent idea to first mix several batches, let it cure, and test the material inside one of your old rocket stoves. I'm not convinced that the most insulating and efficent rocket stove is better if it is at risk of falling apart if you look at wrong. One of the issues you face is uneven heating introduces uneven expansion, and uneven heating is made worse by higher insulating value. It might be that inserting a replacable steel pipe introduces an airgap that slows down heat transfer to the cement. And thus prolonging the life of the concrete through slower more even heating while reducing the heat that transfers into the concrete.
Thank you for the feedback, Keith. Great suggestions. I’m agree with you that a stove ought to be durable before it is efficient. I definitely want my rocket stoves to stand up to a good long stare. 😳 Thank you for watching.
What if you poured the first 4" in just concrete and sand, then the full mix, then 4" or so at the bottom. This would give you increased durability at the two main wear points. This might be particularly helpful with the anchor bolts at the top.
Arnold from Philippines, I am an Engr, I enjoyed watching your videos ,mixing of concrete cement, add a litle bit more water on your mixed cement, this can compact the cement in yor bucket, then gently tap the bucket with your mallet until the bubbles comes out, bubbles weakened your cement, that causes crack, in the future, add bars or construction mesh wires to reinforce the the concrete, . Using cardboard is ok, for easy.removal of concrete from the bucket,, when separated the concrete from bucket let the concrete breath, wet the cement , you will notice, it sucking the water, do this thrice day, on the second day ,.. your rocket stove is ready to use it. Your first video is ok but not cured properly and no bars.. the croncrete it shrink and expand xpecially when heated Good Luck
Try cutting the bucket first, then tape the seam. Cardboard for the inner tube, leave it in, burn it out Mix entire cement batch at once. Consider vermiculite, it has a higher melting point than pearlite. Consider Aircrete, it has air pockets Consider adding ceramic wool to the concrete mix.
Thanks for the suggestions, Ken. I’m going to use your method in my next build. I will do an aircrete build in the next few months. I’m going need to learn how to make it first. Thanks for the feedback.
Your proportions of material are fine, even if you like yoy can still add more perlite, the trick here is the moist in that perlite, you should pre-water that material apart, and add it to the mix at the end, so that way the perlite not only is not gonna dry the concrete fast but it is gonna help curing slow the concrete, and not forget to watering the whole thing for several days before you pull it out of the mold. Man, you do that and yor rocket stove is gonna be just fine. When you make a wall out of bricks, you better put them in a bucket filled with water first, otherwise they suck the water out of the cement so fast that wall will crack. Perlite is doing this to your mixture. Good job though. Keep on inspiring others. Eventually, I'm gonna make one of your models, the ultimate I guess. 🤔😜😂
You rock, dear brother!!!! Thank you, for your humbleness, in posting your failed attempt! You have probably helped many viewers, from making the same mistake.
Thank you for your encouragement. I appreciate it. Thank you for watching.
By now you know how many scoops of concrete/sand/perlite you need to fill the entire bucket so mixing a "one fill" batch may be a better idea so as not to get the different qualities in each level, which also may make it more susceptible to cracking. I am also certain you have already thought of this since this failure. Thanks for the watch, I'm enjoying. ciao.
I could give that a try, if I mix it in my wheelbarrow. Mixing more than what I've been doing in the bucket would be difficult. Thanks for the suggestion. Glad you are enjoys the videos. Thanks for taking the time to comment. :-)
Let's say it together : I told you so... one more time, I told you so... But we all love and support you and eager to watch your next video. You are a nice person.
Lol. I’m saying it to myself, Asa. Thanks for your encouragement. I have a nephew named Asa. The name of a king. Thanks for watching.
parchment paper (for baking) might work, it's less bulky and awkward than cardboard and infused with silicone for easy release.
Thanks for the suggestion, Amy. I appreciate it.
@@GreenShortzDIY ...Or kitchen plastic foil, it will stick to the bucket inside with just some water.
I was thinking that same thing
Enjoy your inventive spirit. I read a suggestion somewhere for smallish projects; to gauge how much concrete you might need, fill the cavity with a volume of sawdust (or ?) and then use that volume to estimate concrete required. Keep up the good work!
Remember if you never experience failure you aren't pushing the boundaries far enough.
If you are going to be doing a lot of concrete mixing you might consider making a small mixer. Then you can mix all of the batch at one time and everything will be consistent. While your batch may have been too dry the problem may have been that the components weren't adequately mixed. The process of mixing grinds all of the components together so that every particle is fully wetted. This is particularly important with perlite since its surface is very good at trapping air. It is essentially glass foam. A good mixing will likely take 15 to 20 minutes.
Also, as was said by Copenhagen King, motor oil is commonly used as a release agent for concrete. You might also use caster bean oil.
I'm super intrigued about building a rocket stove & I was wondering about the perlite option to lighten the weight. Thanks for including the videos where things don't go perfectly- it's helpful to learn those things too, before taking on a project.
I did finally weigh both concrete stoves, with and without perlite. I can't recall exactly, but I think the concrete-only stove weighed between 75 and 80 pounds and the perlite version was 15-20 pounds lighter. I remember being shocked by how much weight the perlite helped shed from the stove. AND, it provides insulation value too. Thanks for watching.
@@GreenShortzDIY that's a huge difference in weight. Thanks for that
Thanks for sharing the failures, knowing what went wrong is good for us knowing how not making the same mistake, in this or any other project. Appreciate it!
I would also suspect the use of dirty creek sand vs clean sand may adversely affect the strength of the concrete.
Yep, organic material in concrete is not good.
I've experimented quite a bit with perlite concrete mixtures. Perlite significantly weakens castings, especially when moisture is present. The cardboard liners you used in earlier videos gave better de-moulding than anything I have tried and I will definitely use carboard in any future projects. I was fearful you might follow the advice about using demould waxes, knowing from bitter experience that nothing will come close to the easy de-mould you had with the cardboard. Good work, thanks for sharing.
Thank you for the feedback. I concur on the perlite. I’ve considered putting a seam in the pour with a piece of chip board, to force the expansion crack. I’ve had success strapping a cracked stove with steel pallet straps. I definitely think I’d go back to the cardboard for my next casting. Thank you for watching.
@@GreenShortzDIY for what it's worth, I think cracks forming on heating release stresses inherent in the casting and, if the cracked part is bonded back together it becomes stronger than it was before. I've bonded cracked parts back together using a slurry of talc in sodium silicate and the reformed pieces didn't crack again over prolonged use in heat risers etc. I'm considering casting future heat riser tubes as wedge shaped blocks that I bond together afterwards to make a tube, the idea being that there would be none of the stress inherent in a closed circle.
Glad to see the mask. Perlite dust is terrible for the lungs as well, it is essentially expanded glass. Nice series on these concrete rocket stoves, I am inspired to try making one.
Thank you, Scott. I'm planning to make an aircrete one soon as well. Thanks for watching.
I like your positiveness, thank you for teaching how to build a rocket stove and the message behind that we can learn from our mistakes without giving up. thanks
Thank you for saying so, Norma. I appreciate the encouragement. Happy Thanksgiving.
I've had similar results with cooking spray. I've had great results with a layer of paste wax (slather it on, no need to buff it on a stove) and warm your plastic with a hair dryer after to get it to release easily. I've used this method for ornamental cement work. I also found that fumed silica made the cement lighter, a bit stronger, and much smoother, but don't know if it would be useful as an ultra fine lightweight aggregate for stoves.
great videos! I came upon some empty beer kegs recently and realized they would make a great shell for the rocket stove. You wouldn't need to worry so much about outside strength, allowing you to increase insulating value of liner. currently a 26lb . stainless steel keg is worth $9.10 scrap value. you should be able to pick one up for under $20 thanks again for videos
I’m no concrete expert or anything, but I did pour a lot of it during my 20+ years of bridge construction. We had a saying. If you’re going to pour concrete, the concrete MUST pour! If you pick it up and it’s dusty, it’s too dry.
Well said !!! I have poured a lot of concrete ... and the worst thing that can happen after removing the formwork is finding large patches of concrete missing because the mix was too dry ... 😵💫😵💫😵💫
Remember: The concrete provides the strength. The perlite provides the insulation. The more perlite you add the weaker the mix will be. The less perlite the stronger the mix, but the less insulation quality. I would much prefer, if it were mine, to make the mix stronger and forgo some of the insulating quality. A stove that is stronger, but doesn't insulate as well, is better than a very well insulated stove that falls apart after a couple uses, if it lasts that long.
Thanks Ken. I agree with your preference. The rocket stove I made with the crack resistant concrete and an armature has not cracked. In my mind it performs just as well as the perlite insulated version. I’m an experimenter, of course, so I like to try different applications. Thanks for the feedback. Thanks for watching.
Thanks for sharing your failure, so we get to avoid repeating your mistake.
This is more valuable than sharing your success.
Few things I've noticed from my experience: cardboard liners all the way, I think the 1st layer needed to be tampered better bc the perlite made air pockets on my fire brick too, and the fresh cement in mold is brittle until light grey appears. I didn't have good luck with Pam for release agent either. Wait until concrete shrinks with it upside down on blocks... live and learn right? Thx for another lesson
Hopefully it wasn't the Atl cup... lol
Well the Falcons have been know to blow a solid lead. :-) you just reminded me I need to link your channel. Forgot to add that in the description. Thanks for the feedback. Hope you are well.
GreenShortz DIY I'll get a vid of the fire brick I made. I feel extra binder is required to wick moisture held in the perlite/verm... I am impressed how well my pedestal held up under the 80lbs tower and heat. I made a back up that didn't need yet. Should be perfect for an example. Thanks, for everything...
You always learn something new each time you make a mistake...That being said, your stove keeps getting better.
Thank you, Lydia. Thank you for watching.
I love what you are doing. I worked for 22 years in a RD dept. The ole saying is two heads
Are better than one. Only problem on you tube there are so many unqualified people adding
There in put. But that’s ok . I plan to watch this to the end. I love the content as the way you
Do your videos. I subscribed!
Sos un genio!!!! uno aprende mas de los errores, que de los aciertos.
When concrete cures, it shrinks a bit. All you needed to do was wait a few days and the casting would have fallen out on its own.
Ha. When I’m making a video I can’t wait a few days. Sometimes I just have to go. Thanks for the feedback. Thanks for watching.
we used to use diesel as release agent when pouring concrete on wood forms, also have used plastic liner as release aid , I'd suggest using sack crete with the fibers or just go with Georgia clay and straw!
LOL! IMHO, everything you did BEFORE you listened to /obeyed/followed all those asinine suggestions worked, were more correct and far, far better!
Ha. I’ll take that as a compliment. Lol. The main reason I take the approach I do, is because while I do usually trust my instincts and knowledge, I also know I don’t have all the answers and I want to learn new things myself...even when that means failing. I still post those videos because I think there is still value in the process. To your point, when we see what doesn’t work well, next to what did work just fine, the best path forward is clear. Thanks for letting me be philosophical this morning. :-) Thanks for the feedback, and thanks for watching.
On future pours, I have some ideas that might be helpful. attach a hinge and latch to the bucket, and then slice in down the center into two halves. A day after the pour, you can open up the bucket like a book.
My second suggestion is to make the center plug out of a wooden 4x4. Use a table saw to slice it lengthwise in two places so that you have three planks. Make the center one slightly thicker than the other two. Then use a table saw to trim the four corners so you end up with a slightly hexagon shape in the cross-section. A day after the pour, hammer out the center plank, and the other two should come out easily.
Another thing that might be worth trying is to make the pours into two sections. Make an inner shell first with a high perlite mix, and after its complete, pour an outer shell with very little perlite for more strength.
Great suggestions, Ron. Thank you. Thank you for watching.
Decades ago I tested concrete for an engineer. We were testing on a military base and the specifications call for no more than one inch slump.
The test is carried out using a metal mould in the shape of a conical frustum known as a slump cone or Abrams cone, that is open at both ends and has attached handles. The tool typically has an internal diameter of 100 millimetres (3.9 in) at the top and of 200 millimetres (7.9 in) at the bottom with a height of 305 millimetres (12.0 in).The cone is placed on a hard non-absorbent surface. This cone is filled with fresh concrete in THREE stages. Each time, each layer is tamped 25 times with a 2 ft (600 mm)-long bullet-nosed metal rod measuring 5/8 in (16 mm) in diameter.[2] At the end of the third stage, the concrete is struck off flush with the top of the mould. The mould is carefully lifted vertically upwards, so as not to disturb the concrete cone.
The concrete then slumps (subsides). The slump of the concrete is measured by measuring the distance from the top of the slumped concrete to the level of the top of the slump cone.[
Your videos are great, and inspirational. I do appreciate the part about learning from your mistakes so I have a better chance to succeed the first time....... I'm also glad that you get compensated for these mistakes, because you earned it. Keep doing what you do man!! I have to admit I did chuckle when you broke out the cooking spray.
I like what you're doing with the rocket stoves, and I'll be the first to tell you that I'm no concrete man per se'. I have worked with it a little down through the years, and I always thought you were supposed to strive for a single pour! And that brings up another aspect to it. It should be a pour, and not a pack, or tamp. At least that would be my approach. I spent 49 years in the house painting business, and I've done everything from fence posts to sump pump sinks, to French drains etc. And the last thing you want to do is pound on green concrete. Even if you dont do obvious appreciable damage, you can hairline it which will come back later as a heat crack. im not sure what would be a better release, but roofing felt comes to mind for me. Seems like it'd be thinner to work with, and should release okay, but that's a guess on my part??? Wax sounds good but how to apply it is my question. Some kind of a grease stick!!!?? I don't know.
Hey have fun, I'm enjoying watching. 28 days sure surprized me. But I guess the longer the better. Especially when heat is involved.
Lol the funny thing about wire cutters, when I cant find em, just buy another set so now theres like 4 sets around here somewhere.
Wire cutters are the tool version of Bigfoot, just smaller.
I think you need Crisco or something like that for mold release. I might try that design if I get some time this summer.
Crisco it is. Since you got the first comment, I'll go with your suggestion. Thanks for watching. :-)
I'm curious how AirCrete would hold up. It would be much lighter.
I suggest using a mason’s tub for a lot easier mixing. No sharp corners, and shallow rather than deep. Various sizes available, and not expensive. Best quality ones where contractors shop.
Im in capital now, and watch this video with a cigarettes 🚬 and some coffee ☕ in the middle of the night 🌃 makes me feel like im home now. Its fun and its kinda soothing, thanks for the video man, keep doing something like this, something that makes home better and better.
:-) There's no place like home. Glad this helped you feel closer. Save travels to your village.
Not enough combiner (Concrete) I think. Maybe 3 parts perlite, 2 parts concrete, & 1 part sand.
Plus, use a thicker oil like shortening or Crisco then dusting it with dry concrete or sand. Same idea for baking cakes (butter & flour)
Any alternatives to perlite? According to wikipedia perlite is a no renewable source (But maybe is doesn't get destroyd by using?)
18:58....
"When We FAIL... We TRY AGAIN."
You OWN that Statement. "Almost" hint hint- sounds like something you should print out on a Tshirt.....
Good Advice. For EVERYONE!
God Bless. Nice Video.
"HE Doesn't give us all we Want, HE Gives us the Tools and Motivation to Make It Happen..."
After how many minutes of running did it start to crack?
Anyway, it's just a nice circular stove.
In the world there are many rocket temples because they have burned and have circular columns.
Vasolene/ petroleum jelly would have worked great as a form parting agent - just be sure to slather it on thick in the corner
You sir, have a great Attitude! Failure is knowledge... Try, try again!
I couldn’t agree more. Thanks for the feedback and encouragement. Thanks for watching.
As long as you're willing and able to learn from the failures, of course. ; )
nice work. it still works. you did not fail
Have you ever thought about using one of these for ambient outdoor heat on cold days like restaurants do with those propane heaters? I was thinking you could take an old well pump tank or something and drill or plasma cut a bunch of small holes in it and attach it on top of the stove in a way that it is solid but easily removed.
That’s a great idea. Thanks for the suggestion. Thanks for watching.
I used to do commercial diving and we did underwater concrete pours. It was inevitable to get some concrete in our gloves and after pumping concrete into forms and using our hands to guide the tremmie hose and concrete the other divers laughed at me for constantly using hand lotion on my hands at the end of each day. After a week their hands were dried out and skin cracked all over, my hands were slightly dry but not nearly bad enough for my skin to crack. So personal suggestion if working with concrete and exposed skin wash skin thoroughly then apply liberal amounts of hand lotion. It pays off.
If you make a lot of these then attach the wood blocks to the Outside, wide end, top of the bucket. Then you don't have to try to position them to break it out of the mold bucket. I like to leave a thick throw rug under it, so when it the stove slides out of the mold the fall doesn't break it. I do this with concrete weights as well.
Thank you for the tip. Thank you for watching.
a side note... have you ever tried "Air Crete" would make this portable (though air crete is kinda soft so I have had to trowel on a light mortar mix/stucco on the outside to act as a shell)
I have considered air crete. I just need to learn how to make it. I know Honey Do Carpenter has a foamer design he sells. I've gotten lot's of comments suggesting are crete...will do this at some point. Thanks for the suggestion.
Hi, use compressed air and blow around the edge to loosen the mold.
fill only 1 centimeter from the edge so you do not need the wooden blocks.
Thanks for the suggestion, Martin. Thanks for watching.
No card board. Use leaves, ( fern for example) makes a pretty design.
Loved the " I told you so " option.....LOL
I'm still teachable. :-) Thank you for watching. Glad I gave you a smile this morning. By the way, he responded with a kind "I told you so."
just use some Rawlbolts afterwards when its set for the pot stands ?
The ratios looked pretty okay, you would have gotten a better result if you had hit it with a cement vibrator when pouring. This would have gotten thing much more evenly distributed.
Maybe in the future, mix up some small batches and make little fire bricks with various mixtures and see what ratios and consistencies work the best for your needs.
But 110% use a cement vibrator next time. Gets all the air out, homogenizes the mix, and makes your finished product perform waaaaay better.
Thanks for sharing the progress with us!
Great vid, thanks! I'm thinking of trying this, but I've built many coffee can size rocket-stoves with holes drilled to allow the wood gas to travel outside the burn-chamber, up, and with more holes at the top allow the gas to go back into the chimney and be reignited in beautiful blue flames. So I'm thinking of adding this feature by attaching a small diameter cardboard tubing stuffed with paper towels. The tubing would horizontally leave the burn chamber, maybe 3 inches, turn at a right angle, then straight up close to the top of the chimney, turn back and connect to the chimney. After the tubes all burn away it should allow the gases to flow through to be reignited. that the plan anyway. Sound crazy?
Sounds like a cool experiment. I say give it a try. That’s how innovation happens. Dyson created his new vacuum after 5000 prototypes. :-) I’d love to know how it turns out.
Best outcome, we get another iteration :D
Ha. True. 👊🏻👍🏻
I suggest you use thick Lard to lubricate the form work rather than spray on olive oil - which just got absorbed where thick Lard would be more durable
From professional MASON. Mix 3:2:1 cement in ONE batch. Calculate volume needed, mix in wheelbarrow with back and forward motion of a regular SHOVEL. ADD one squirt of dishwasher to water. Start mixing with less water than required, add extra water slowly in handful at a time
Line the bucket with plastic cling wrap , that is the easiest sure way to get an effortless release . It's gonna leave a little texture but it's guaranteed not to stick !
Good tip. I’ll. Have to give that a try. Thanks for watching.
Informative and honest useful information. Thanks.
Anything the mind can conceive so can it achieve you are proving that and inspiring people .tHANK YOU FOR YOUR TIME AND VIDEO'S. I would like to add a few thought's the parchment paper liner is perfect, the perlite does hold water measuring water each time is as important as the other, longer bolts on the inside would be better and a washer, the outside bolts could be used to release the bucket screw them gently to allow air to escape should help to release.I hope to follow yours and try myself. Again thank you..
Thanks for the feedback and suggestions, Michael. Thanks for watching.
Mix the water with the cement and incorporate the perlite after so that all the water will go to the chemical reaction of the concrete hardening and non will be lost in the perlite sponge.
Why don't you use the threaded inserts on the outside so that you can take them off after its set
Bro! PAM? No. Should of lined the bucket with strips of bacon.
Just another source of proof that everything is better with bacon. :-) I’m hungry now. Thanks for watching.
Very good video!!!! It seems that it is better to fail by adding more water than to leave the mixture too dry ... On the other hand ... as I was watching this video..for the part that you sprayed the bucket and the PVC with the cooking oil ... I said to myself ... it's going to be very difficult to get the PVC and the bucket out of the concrete. The cooking spray is simply washed off with the concrete mix ... You better stick with the cardboard approach.
I am in the process of making a small forging unit (for melting aluminum) ... and the proportion of my concrete will be 4 parts perlite, 2 parts sand and 1 part Portland cement. That's what I can get at the hardware store. I will use chicken wire to reinforce the concrete. There is a second idea which is to replace Portland cement with plaster of Paris ... what do you think? Thank you, and you have a new subscriber.
Thank you for the feedback. I recommend using the plaster of paris. I’ve got a plaster and perlite forge that has stood up to the heat well. I did an aircrete forge, with portland. It insulates well, but the parts that glow red, crumble once they cool.
Mix your aggregate in a shallow pan rather than a bucket. It will be easier to work. Make a single larger batch to provide continuity in your pour.
I have purchased a cheap concrete mixing pan. Works so much better. Thank you for the suggestion.
Not enough concrete in batch with too much peralite an no beating on sides of mold use air pressure from air gun through bottom hole, make sure wire mesh lines up with cutout on bucket, I've used grease as well as motor oil but you found out about cooking sprays! Tim
Excellent information, when's the version with the build in water heater coming?
You know you wanna...
I do wanna. I've been thinking about this for a while. I've got a few more versions of the stove I want to build this summer. Will likely try the water heater version late summer or early fall. Thanks for watching.
Watched a few of your videos, and I love the experimental aspect of your projects. Also, you go a long way to involve your commenters into your process, which seems to be exactly what youtube should be all about. Keep up the great content.
Thanks Allen. And I agree, community is one of the beautiful opportunities here on RUclips. Thank you for watching and your encouragement.
Try a wax paper loner next time. Tape it around the riser tube. Tape it to the inside of the bucket.
Thanks for the suggestion Patrick. I may do the wax paper on the PVC riser form. I want to see if I can get the main body of the rocket stove out with just grease or oil. Thanks for watching.
This is an old video but i'll give you some feedback from our lab. We use WD-40, on our metal molds, but they come apart in two halves. For plastic molds, we wait a minimum of 48 hours (longer is better) punch a hole in the bottom of the mold, and then spray compressed air in to get it to release. a little concrete usually busts off the edges but if you let t cure longer (curing is a chemical process, it doesn't "dry") You can reduce this. Also I'm very interested in how this would perform with a fiber admixture or metal fiber admixture.
Jonah, thank you so much for the excellent feedback and suggestions. I will definitely halve my forms for the next go round. I like the idea of adding fiber as well. Thank you for watching.
Nice project. Saw your first video and this one. I think you don't have enough water and not enough cement. I'll try the project myself but will not use perlite. Instead I'll try to coat the armature wire in aluminum foil (several layers). It deflects heat. I'll just leave area at top and bottom for concrete to connect and make some holes in the foil for connection.
Good luck with your next version.
This might seem like a silly question but why don't you mix "your" cement with Georgia clay? 🤔
And you already found out but the longer concrete has the ability to remain wet the stronger it will be. Always mix your concrete wet. If your laying stones in , say a stone wall you should mix your mortar /cement a little on the dry side because stone does not absorb water like brick or cement blocks
Hi Dan. Did you find my Georgia clay (cobb) version of this rocket stove? Thanks for the concrete tips. Thanks for watching.
GreenShortz DIY I'll have to check them out I want to build a rocket stove/chimney that can throw a little heat too . I hope I don't sound like a jerk I enjoy your videos I like when you show your failures too keep up the good work.
@@danfay4860 No worries Dan. Thanks for the feedback.
@richard mccann Please make this statement more legible, as it seems you have good information to offer here, but I cannot understand it. Thanks.
A bolt going through the center of the bucket, with the threads coming out the bottom of the bucket, and a knob screwed on will make it easy to simply pull the bucket off after curing.
I'm thinking you could have wrapped your forms in wax paper and tape. The bucket could have been coated in motor oil and had wax paper inserts then add the mixture. So even if it stuck to the paper, that could easily be burned off.
Why don't you use a Superplastisizer? Also known as a water reducing admixture.... seems like it'd help a lot.
I don't think there is any other video out there as well explained, or watcher oriented" as you're videos are.!! I do like the way you explain everything SO Well.!!
I know you've been getting a lot of good comments, on how to improve the "Release process" but I think you should, line the inside of you're bucket with a Thick plastic" it would come out a whole lot easier.!! However, it would need to be removed from the bucket, while the plastic liner could, be peeled off the side of the stove, if let set up over night, the plastic liner will be to hard to get off, and make a melted plastic smell evertime the stove was used.
Thanks for the feedback and encouragement. You are indeed an angel. Thanks for watching.
someone read my mind Georgia clay they use it with straw for chimney bricks there's an old-timer in Savanna that still does it the old way you could make your on bricks to set your stove on.OK, I hear you I think I said enough.GREAT WORK
I need to make another clay version of this stove. I’ve got a pile of Georgia red waiting. Thanks for the encouragement.
I too thoroughly enjoyed the experiment. We learn far more by our failures than our incidental successes. This video ... made me subscribe to your channel... Thank you... BTW... in not reducing the weight.... perhaps.... set some kind of handles on each side... to carry the stove to new locations... perhaps 2 people taking a handle?
I like the handle idea. I'll have to tray that in my next build. Still not a stove for a 5-mile hike. :-)
@@GreenShortzDIY just thinking some kind of handles would help 2 people carry it across the yard easier.
😭😭😭😭😰😱good to never give up!! Greetings from the Netherlands 🇳🇱
Thank you for watching, Wilbert.
@@GreenShortzDIY I totally understand trying to make the perfect heater ! You inspire me a lot
maybe you can make cake mixtures for baking once you are ready to trial cook
Maybe soak enough/over enough perlite in water and scoop as needed for mixture
in your other video, where you used a terracotta flu liner on top of bricks... instead of using PVC as your chimney form, could you use the flu liner (then just leave it in ). maybe notch the flu liner with your angle grinder so it could double as your pot stand offs( fill bottom of bucket with sand to depth of pot standoffs or notch the bucket so they poke through). so in your form the flu liner sits on sand to top of notch(or poke through), then your jug, surrounded by your bucket... mold release... crisco (just something to try) I have played with perlite for a while... best results is when I create the cement/sand/water mix get it all nice and creamy then slowly add perlite until I have the desired consistency (depends on if you want it pourable or packable) also to make it more pourable with a dryer mix they have a product called Flow Control which makes the mix looser before it sets... have only used that when making slabs for a firepit, but it does help...
Thanks for the feedback and suggestions.The flue pipe idea is an interesting one. Also appreciate hearing your technique on mixing in the perlite. Thanks for watching.
Great video man I enjoyed watching it but maybe you should've followed your inclination to take my advice. Oh well still a fun video and a great project. EDIT I didn't want to sound like a know it all buuuut youu did give me the right to an I told you so lol.
Ha! Yes, yes I did. :-) I think I had the mixture too dry. Did you notice? First it was way too wet so I mixed in more dry materials. Would appreciate your thoughts. Thanks for watching.
GreenShortz DIY well I did notice that it was way too dry and in my opinion maybe next time mix all the ingredients forgo the extra perolite and make sure that it has enough moisture in it so you can properly consolidate it that you cqn improve on the next attempt also i noticed the threaded inserts great addition the cooking spray was a good idea too but maybe go for a heavier oil that has a better film streangth such as engine oil. I appreciate your interest in my ideas and greatly enjoy watching them looking forward to your next one 👍 :)
Thanks for the feedback. I was guessing the cooking spray was a little too weak to release well. Would Crisco have the film strength needed? I was trying to go with a food-grade product. But, if you think it really ought be engine oil, I'll go that route. Thanks again.
GreenShortz DIY no problem man and I do believe crisco would work for what you're doing also if you let it cure for 2 days and use the proper ratio the mallet is not going to hurt it one bit keep up the good work man
Someone already suggested wax/cooking paper and that with cooking spray might do the trick. Maybe put the oil between paper and concrete?
Hey nice video, man! Really cool!
I suggest geopolymers as a material. Better heat and chemical resistance. Or as a fire or heat resistant coating. Fire is not only damaging materials through heat but through very corrosive gaseous substances in the fume. Along with the heat it is a extremely corrosive environment and Portland cement is a rather weak material.
I'd say even easier is to just mix perlite with diluted waterglass which gives a interesting refractory like material for coating and insulating the fire chamber.
I have so many projects but I have hope that I will find some time soon to make a rocket stove.
Have a good!
Funny, but I believe the mix wasn't too dry, you just never compacted the concrete enough. High frequency vibration is recommended for low-water content concrete. Tapping with a piece of lumbar, lol. I use water at a ratio of 0.4:1 water:cement (not concrete) by weight and make some beautiful pavers always. But I use a vibrating table at almost 4000rpm.
apply tin lay of grease on the inside wall & base of bucket same for the pcv pipe outer wall before pouring in the wet concrete , will be easy to remove once the concrete dry
Thanks Jack. I plan on trying Crisco grease the next go-round. Thanks for watching.
Copenhagen king was right!! not enough sand+cement to hold the perlite together. more water might have helped but you should of mentioned him; at the end of the video.
Entertaining and educational non the less👌👍
You sprayed your bolts with the release agent, that's not good for having the Crete mixture to adhere to them. Go back the cardboard you know it works for you with a used bucket. For a release agent to work the surface needs to be pretty pristine.
I love the racecar and construction noises in the background when you speed up the video.
you could call the concrete company and explained to them that you want to add some kind of flake insulating agent like what you used perlite ask them if they have some kind of like bonding agent it seems that the perlite doesn't bond to concrete they might have some other suggestion for you as far as insulation
Thanks for the suggestion, Miniphe. Thanks for watching. :-)
Had a BLAST looking through ur vids. Made an attempt at a Rocketstove myself, a coupla years ago. It went south with NO option for north.... Had the measurements, the 1-2-4 bit, all wroooong. :)
Still, it was a fun project and i LEARNED alot. So keep it up. Iv got my fingers x´d for ya! Greetings from Sweden!
Thanks for watching. Agreed on the learning-by-doing method. It’s more fun too. Thanks for the encouragement.
If you are using 1:2:3 ratio, what is the water ratio that is working for you?
I’ll get a good water measurement on the next build. Thanks for the question.
Nope, you're going to have to either grease the hell out of the inside of the bucket with vaseline or cut the bucket off the mold. It will always crumble if you try to hammer it out. Wait at least a week before you try anything.
I’m going to give Crisco a try. Wish me luck. Thanks for the suggestions and for watching.
Four years late but information doesn't hurt. Maybe you could have salvaged some of the materia that crubled away if your had rewetted it with a spray bottle to give it enough water to complete the chemical reactions.
It also might help to ensure concrete doesn't dry too fast, by again spraying it and wrappin it with plastic.
Lastly it might be a decent idea to first mix several batches, let it cure, and test the material inside one of your old rocket stoves.
I'm not convinced that the most insulating and efficent rocket stove is better if it is at risk of falling apart if you look at wrong. One of the issues you face is uneven heating introduces uneven expansion, and uneven heating is made worse by higher insulating value. It might be that inserting a replacable steel pipe introduces an airgap that slows down heat transfer to the cement. And thus prolonging the life of the concrete through slower more even heating while reducing the heat that transfers into the concrete.
Thank you for the feedback, Keith. Great suggestions. I’m agree with you that a stove ought to be durable before it is efficient. I definitely want my rocket stoves to stand up to a good long stare. 😳 Thank you for watching.
Angle grinders are like giant Dremels, lol, extremely versatile.
That is the truth. :-) Thank you for watching.
What if you poured the first 4" in just concrete and sand, then the full mix, then 4" or so at the bottom. This would give you increased durability at the two main wear points. This might be particularly helpful with the anchor bolts at the top.
I like that idea, Robert. Thanks for sharing and thanks for watching.
The card board box was easier to pull out the project.
I can use this for an off grid cooking.
Arnold from Philippines, I am an Engr, I enjoyed watching your videos ,mixing of concrete cement, add a litle bit more water on your mixed cement, this can compact the cement in yor bucket, then gently tap the bucket with your mallet until the bubbles comes out, bubbles weakened your cement, that causes crack, in the future, add bars or construction mesh wires to reinforce the the concrete, . Using cardboard is ok, for easy.removal of concrete from the bucket,, when separated the concrete from bucket let the concrete breath, wet the cement , you will notice, it sucking the water, do this thrice day, on the second day ,.. your rocket stove is ready to use it. Your first video is ok but not cured properly and no bars.. the croncrete it shrink and expand xpecially when heated Good Luck
Try cutting the bucket first, then tape the seam.
Cardboard for the inner tube, leave it in, burn it out
Mix entire cement batch at once.
Consider vermiculite, it has a higher melting point than pearlite.
Consider Aircrete, it has air pockets
Consider adding ceramic wool to the concrete mix.
Thanks for the suggestions, Ken. I’m going to use your method in my next build. I will do an aircrete build in the next few months. I’m going need to learn how to make it first. Thanks for the feedback.
Thanks for allowing me to watch you make these mistakes!
I'm an experimenter...sometimes stuff works like I want..other times it doesn't. Hopefully it's entertaining either way. :-) Thanks for watching.
I think your original mixture was ok. Too much perlite is nuch dry. All tha improvements were amazibg. Very nice work. Greetings
Hi Henry. Thanks for the encouragement and the feedback.
Have you tried aircreat
Not yet Gary. I need to learn more about the method. But, I will at some point soon. Thanks for the suggestion. Thanks for watching.
Your proportions of material are fine, even if you like yoy can still add more perlite, the trick here is the moist in that perlite, you should pre-water that material apart, and add it to the mix at the end, so that way the perlite not only is not gonna dry the concrete fast but it is gonna help curing slow the concrete, and not forget to watering the whole thing for several days before you pull it out of the mold. Man, you do that and yor rocket stove is gonna be just fine.
When you make a wall out of bricks, you better put them in a bucket filled with water first, otherwise they suck the water out of the cement so fast that wall will crack.
Perlite is doing this to your mixture.
Good job though.
Keep on inspiring others.
Eventually, I'm gonna make one of your models, the ultimate I guess. 🤔😜😂