No Welding, No Casting - DIY Rocket Stove

I'm trying a different approach to building a Rocket Stove as compared to most of the builds you find on KZbin. Instead of welding metal pipes or casting refractory cement I built it out of vermiculite board.
The SketchUp file shown in the video can be downloaded from my Google Drive: drive.google.com/drive/folder...
Major inspiration to create my own design came from:
Loz Harrop Rocket Stove playlist:
• Rocket stove builds
Peter van den Berg's Batch Box Rocket:
batchrocket.eu/en/workings
Time Stamps:
00:00 Why Vermiculite Board
00:42 Rocket Stove Design
01:23 Rocket Stove Science
02:21 Rocket Stove Build
05:44 Test Burn
06:25 Planned Upgrades

[@rockcrusher4636]

Excellent, please continue, the best vortex I have ever seen. Cheers.

[@BitsOfInterest]

Thanks! I learned from the best on batchrocket.eu 😁👍

[@renelouter]

Great piece! Craftsmanship

[@fourthchute]

Very nice looking forward to the followup vid

[@BitsOfInterest]

Thanks! Here's the follow up: kzbin.info/www/bejne/o3KvaqKBhqisnZo

[@131277stefan]

Great video!!! Informativ, no disturbing music, not boring... One easily trust you!

[@BitsOfInterest]

Thank you for the great feedback! 👍 I've watched a lot of rocket stove videos and tried to put together everything I learned and also give credit to who I learned it from. I also tried to make sure people understand vermiculite board is not the perfect material because it's so brittle. I'll address some of those issues in my next video that I've started planning for. It will take weeks (again) to build, film and edit but hopefully it will be done in December if it doesn't rain too much. Edit: sorry, thought this response was on another video so I had to modify my reply.

[@terjelisether3755]

Nice work! I like this proof of concept

[@BitsOfInterest]

Thanks! I made it work better in the follow up video: kzbin.info/www/bejne/o3KvaqKBhqisnZo

[@mikeconnery4652]

Nice build and good explinations

[@BitsOfInterest]

Thanks! 👍

[@antoncolbo]

Very nice project design. Interesting that the stove develops 2 vortex swirls inside the chimney. I would try this project with a single but larger 45 degree baffle on only one side of the back of the firebox so all of the flame vortex turns in one direction inside the chimney. Did you install a taller chimney or add secondary air tubes?

[@BitsOfInterest]

Thanks! Regarding the single vortex; on batchrocket.eu it's argued a single vortex climbs up the chimney faster leading to less complete combustion. The double vortex causes a very turbulent mixing of combustion gasses and air. The flames also spend more time in the bottom of the chimney, heating it up more also leading to better combustion. I'm currently working on the upgrades I mentioned in the video. If the weather cooperates with working and filming outside I should have a new video up in a few weeks.

[@KostasCreatingSustainability]

That is seriously good.

[@BitsOfInterest]

Thanks! :)

[@audiokees4045]

This is a nice idea for a movable stove for in a tent or camping. quick setup and not heavy.

[@BitsOfInterest]

The exhaust is close to 800C/1500F and even hotter with the upgrades in later videos, so I would keep it outside your tent 😉

[@lancerudy9934]

Nice

[@sauravbasu8805]

If of the two slanted doors at the bottom one is made longer than the other ( so that wind enters at an angle ) , will it create a vortex of fire ?

[@BitsOfInterest]

It doesn't matter. As you see in the video I already have a double vortex, so the flames are mixing well with the secondary air that I'll be adding. The longer the flames spend down below, the better. It heats the core facilitating a cleaner burn instead of heat going out the top.

[@TheSateef]

very nice idea. i plan to do something like this for a greenhouse heater. how is the design going? to you have an update on the whole thing? does the vermiculite board hold up to the high heat over time? thanks

[@BitsOfInterest]

I have two follow up videos where I add the enhancements I mention at the end of this video. The vermiculite certainly holds up to the heat, but it's very brittle, so you need to toughen it with something like water glass so that you don't damage it when you put wood in. If you're making a heater you can use what you see here as the heater core and turn it into a rocket mass heater, meaning you'll funnel the exhaust through a brick or cob structure that can store some of that energy instead of sending it all out the flue 😉 Edit: You can think about it as building a box around the heater core that exhausts at the bottom so the heat is forced down and heats up the mass in the process.

[@PeterFletcherDNADeliverer]

Great work, really liking the design.

[@knightmare1015]

Very cool! I bet this would be epic with all the upgrades that mentioned and used fire cement. And it would be evern cooler of you could use wood pellets.

[@BitsOfInterest]

I built this because I have a lot of sticks falling in my yard, so it's a cool and quick way to get rid of them. That or make wood chips out of them.

[@renefriis-christensen5513]

Very cool project! Is there anywhere we can find your SketchUp files of the stove?

[@BitsOfInterest]

Thanks! As I explained in the video, I tried to keep it as simpel as possible, so most of it are boards cut in half. Sometimes they get cut in half again ;) I just uploaded the file to my Google Drive: drive.google.com/drive/folders/1PVIpUuzQYxrEZtL_QHfcKIiIe9FMQnRP?usp=sharing

[@lasaramicael3009]

Hola. Por el color del fuego has logrado entre 900° y 1.200°! Una combustión casi completa de la madera, 85 a 95% de combustión 👍. He leído los mismos libros que vos. Voy a hacer tu modelo. Será mi 3er intento. Muchas gracias, muy útil y bien explicado tu tutorial.

[@BitsOfInterest]

Muchas gracias. No hablo español pero tengo Google Translate :) Buena suerte con tu construcción. Tenga cuidado con el tablero de vermiculita, es fácil de dañar.

[@bmull81]

@@BitsOfInterest - for the benefit of all, this is the translation:- Hello. Because of the color of the fire you have achieved between 900° and 1,200°! An almost complete combustion of the wood, 85 to 95% combustion 👍. I have read the same books as you. I'm going to make your model. It will be my 3rd attempt. Thank you very much, your tutorial is very useful and well explained. ...................................... Thank you @lasaramicael3009! ¡Muchissimas gracias! You make a very good point - the flame colour is closely related to the true flame temperature, and I agree with your assessment of the efficiency. ............ This, folks is why the 'iron pipe' stoves cannot truly rocket! Iron and High Carbon steel are no longer reliable at 1200C. Some years ago in Australia we bought a little 'stainless steel' stove that burned OK, but never exceeded 400C, so it never 'ate the particles' properly, never mind oxidising the CO to CO2. By tweaking it and providing a strong draught we got some reduction in CO, and then it came apart! It was probably a cheap stainless, but it was still not hot enough to purge the CO to CO2 fully, and it came apart! 🙈🙉🙊¡Que lastima!

[@voidisyinyangvoidisyinyang885]

cool experiment!! thanks - there is a dude who used ceramic fiber board in his steel stove!! He had a secret though that he didn't explain. So I phished it out of him and now he is going to make a new video explaining his secret. haha. It's called Double M Innovations - that's his channel. thanks

[@BitsOfInterest]

Thanks! I'm using vermiculite board and believe that's a little different than ceramic fiber board. For one it was cheaper when I was looking. I don't like to keep secrets. I make videos so that if you think it's cool you can make it yourself. That's how I get ideas myself too, so I'm just giving back to people that are interested in this kind of stuff.

[@voidisyinyangvoidisyinyang885]

@@BitsOfInterest I'm just gonna jam a ceramic fiber board insulation piece under my steel baffle - to radiate heat down for a cleaner hotter burn. I just have a Two Dog stove in Minnesota - it's only 11 inch by 18 inch by 11 inch high. So also I'll use an 8 inch Ecofan and also steel duct heat exchangers - that you wrap around the duct pipe. I have a 30 degree duct pipe into a side wall and then use a big bucket of water for thermal mass. I would love a clean burn 1100 F. or whatever but the issue is how to keep is safe in a small hut setting - with a bed nearby - and also how to store the heat, etc. In a very cold climate you want heat radiating immediately - not just a slow thermal mass. Anyway - I like to learn - so thanks for the experiment. Yes the vermiculite is what the Century Stove baffle is that the "Double M Innovations" dude has - he did not even mention he had a baffle in his stove - and so then he goes - but I didn't say I removed the baffle! haha. People had no idea how his stove set up worked. Hilarious. I don't think he was trying to hide it - he just didn't realize he had not explained the real details. thanks

[@BitsOfInterest]

@@voidisyinyangvoidisyinyang885 the idea with a rocket stove is that you're basically building it out of any kind of high temperature insulation so that the fire gets a chance to get hotter instead of radiating it out through the steel right away. I'm sure you could line the inside of a wood stove to do something similar. That said, if you have it in a small cabin you may want that heat radiating from the steel firebox. An insulated stove may get too hot or dump it all outside through the chimney.

[@voidisyinyangvoidisyinyang885]

​@@BitsOfInterest yeah the Hearthstone wood stove has the ceramic fiber board - I think it's vermiculite that is technically a type of ceramic - and it's above the metal baffle. Only the baffle is stainless steel that has a 1400 F. temp limit compared to 1000 F. for just steel. So also they use soapstone in the back of the stove with more vermiculite - so to protect the wood stove steel. It's all kind of tricky to increase the heat yet not burn out the steel. haha. Also to radiate yet insulate... I want the thermal mass radiation - I have the wood stove lined outside of it with brick and then a big pot of water on top. I'll try put the ceramic fiber on top of the steel baffle and hopefully the baffle won't get too hot. That way the fire box won't be too small. Should be interesting. I'll get an infrared thermometer gun from Harbor Fright - to see what happens. thanks

[@davidkolbe2288]

@@voidisyinyangvoidisyinyang885 ok ok

[@victoryfirst2878]

GUIDING the flames really make a difference fella. Should I say BIG DIFFERENCE.

[@paulshull9247]

Does the fuel /air ratio need to be 50/50 RE the secondary angle iron ports with pre heated air, so as to maintain not too fast of a burn of the fuel ( wood ), or would a flue only be needed at chimney and or air inlets, so as to adjust heat output and burn efficiently. I love your board concept though, for multiple reasons. Thanks for the video sharing.

[@BitsOfInterest]

I did not do the science, I just built it 😜 For air/fuel ratios and sizes I would refer to batchrocket.eu where I got my inspiration from.

[@paulshull9247]

@@BitsOfInterest Thank You for responding with reference url. I know there are alot of designs and many are really close to dims and materials, but was curious about yours ( video ) is because it really eliminates all the jargon of other videos that is pretty perplexing, but yet seems to have a nice even burn ( less smoke that's usually resultant of not enough oxygen to the burn chamber ). Thank You for your response and video though. It's conclusional enough for the non welder like myself that burns metal the moment I hit it with the stick or wire.

[@BitsOfInterest]

Thanks! The reason I didn't include any jargon in my video is because I don't have any :) I don't have the equipment to measure what's an "efficient burn" like on batchrocket.eu. Without a door like in this video it will get plenty of air, but it's probably not optimal. I'm thinking about building a door with a slider for primary and secondary air. I still have to figure out how to make that :p

[@paulshull9247]

@@BitsOfInterest Based on what Ive seen and read on the slider doors,, I think that with your use of the board your heat range is probably at nearly perfect levels for the board & the sliders that I saw on one rocket stove produced heat levels that melted thru the steel ( until he shielded the top riser area with stainless (( that is, the stainless plate added was added on the top section, before it entered into the chimney port )). I do see the potential though with the board you're using though. It's good to see your alternate means of heat without the other skills needed in metal box fabrication.

[@lancerudy9934]

Did you use screws to hold the boards to hold together

[@BitsOfInterest]

Yes, in combination with high temperature cement to seal the cracks. As I mention a little later in the video you should plan to put it together once for the best results. I was running late that day so I put it together and took it apart later to apply the cement, which is not great for the hold the screws have. I just covered the screws in cement to compensate 😋

[@jimfitzgibbon5492]

Bo how well has it held up? You posted this one year ago. Have you had any problems with the board assuming you caged it in with angle iron.

[@BitsOfInterest]

The angle iron frame is doing it's job 😁 The boards stay together and don't get (further) damage. I also needed that frame to attach a metal door in my most recent rocket stove video.

[@SuperCanuck777]

Hi, i see the importance of insulating the furnace and chimney area from heat loss to maintain high possible temp for maximum efficiency. i wish to build the advanced design over the usual tin can simple rocket stove. Please, do you think i could use 12.5mm x 1.2m x 2.4m piece of vermiculite board for £18 to either line a well designed metal or brick stove or even attempt full construction out of it? i appreciate VM board in somewhat fragile.. thanks in advance, Peter

[@BitsOfInterest]

12.5 mm is a little thin. If you use it as a liner for something else maybe it could work, but I wouldn't screw those pieces together, it will just crumble. Maybe you could also use 2 layers to get more insulation value. If you're making the whole core out of vermiculite I'd try to find 25 mm thick boards so you can get screws in the side of a butt joint.

[@SuperCanuck777]

@@BitsOfInterest Ok, thanks for the good info.

[@howtogetoutofbabylon8978]

Awesome Job¡!!! I love outside the box thinking. so in this case you need to build a I think an a metal frame for that all the way around maybe 2 in angle iron just make a casing for it or she sit in cob or she sitting in fire brick just give it some protection but that would be a good liner for a rocket stove if it doesn't totally deteriorate from the heat I don't know did you get the laser gun it'll go high enough to check your heat? and yeah I did a rocket stove a real one and the guy built it for destroyed it took it apart I couldn't believe it like losing one of my own children until I put so much of my life into it. You're right looks like a double vortex at least two same kind of split and went right and left that's still phenomenal great job there!!!

[@BitsOfInterest]

Thanks! 👍 I did make a metal frame out of 1 inch angle iron and folded some expanded metal into a basket almost to protect the bottom and sides of the firebox. Vermiculite board is rated to 2000F (1100C) so it should hold up as long as I can stop myself from poking it with sticks, because then it scrapes little pieces away. I'm publishing a new video about the upgrades in the next few days. It's all filmed, just need to put it together 😁

[@andrewsolano9172]

@@BitsOfInterest how about a high heat refractory mortor on inside when on fresh build BEFORE first burn?

[@thomasstamatelos3322]

Nice job....

[@BitsOfInterest]

Thanks! 👍 You may like my latest rocket stove video where I have the upgrades I mentioned at the end of this video 😉 kzbin.info/www/bejne/n2m3eoCsgdyLbK8

[@thomasstamatelos3322]

Good... keep it simple...greattings drom Lefkada island Greece

[@jimfitzgibbon5492]

Can you post the dimensions of your stove. I would love to make one with out gusting. Thanks, I subscribed I learn a lot.

[@BitsOfInterest]

Thanks! If you are familiar with SketchUp (Free) I shared the 3D model from the video in the description. Just keep in mind the boards I used are 12"x12"x1" so most pieces are 6"x12" and some 8"x12" and 4"x12". You can think of it as two square tubes that fit inside each other. The heat riser or chimney is 4"x4" inside, 6"x6" outside. In this video it's only one board high, but in my next videos it's 2 boards or 24" high. The burn chamber is 8"x8"x18" outside, 6"x6"x17" inside. The 17" is because it's closed on the back, but not the front. In my latest rocket stove video I made a metal door to close that off.

[@justinw1765]

Very cool (well, very hot actually). What I would do to add strength and durability to the structure, is get basalt fiber cloth (sort of like woven fiberglass cloth, but higher temp and alkali resistance, and higher tensile and modulus strengths), mix up a tri silicate blend (sodium, potassium, and lithium with the sodium being the slight majority, followed by the potassium, and just a bit of the lithium) with some powdered activated carbon. "Glue" the boards together with the tri silicate blend + carbon, then layer/wrap it with the basalt fiber cloth, and put more silicate solution on it to affix it to the boards. Should make it pretty sturdy.

[@BitsOfInterest]

To me that sounds like a lot of work with hard to get materials, but I may be wrong 😜 Wouldn't it be easier to mix your own refractory cement and cast it in a mold? Refractory is much tougher than vermiculite board already. PS I did cover the areas with the highest abuse (burn chamber) in sodium silicate and that helped a lot with mechanical damage.

[@3niknicholson]

Hiya, nice vid, I'm interested in making a batch box rocket, ot converting my "nearly" rocket mass heater into a batch box. I've been baking bread for two years in my other build, a J-rocket stove with an old gas oven on top, inspired by Loz Harrop. I realised, as you did, that the vermiculite is as strong as Weetabix so I cast a perlite concrete mix around it to give it some strength. It's an efficient baking oven, but wouldn't win prizes for prettiness.

[@BitsOfInterest]

Thanks! I made a follow up video where I compensate for my choice in material by adding metal on the outside edges and I put a basket folded out of expanded metal inside so I stop digging holes in my burn chamber when I put a stick in 😜 I've received a few comments that I should look into coating it with water glass or sodium silicate. I have no idea how it will work, but it's not going to get much softer than the wet newspaper it's now, haha.

[@3niknicholson]

@@BitsOfInterest I drilled pilot holes for my screws and was very careful, like you say, assemble only once. I made waterglass and tried painting it onto the inside corner where it's started to wear away a bit. but I can't tell if it's absorbed into the material. I might try painting a vermiculite piece with it before assembly for my next build. Meanwhile, I bake bread every week, very economically, and heat my house with my other rocket, very economically, plus it's been good fun!

[@lancerudy9934]

Please have more videos. Thanks

[@BitsOfInterest]

I will certainly make a follow up video when I have time to work on the rocket stove and if the weather cooperates with filming outdoors 😁

[@leonardoalvesqueiroz4476]

Por que a camara de queima do fogo tem a forma de um círculo?e por que a parte de queima da lenha tem um estreitamento para o fogo passar para camara de combustão? Muito tttoo

[@BitsOfInterest]

Está explicado no vídeo e no site batchrocket.eu Ajuda os gases (gás de madeira e ar) a se misturar e obter uma melhor combustão desculpas por erros de digitação do Google Tradutor

[@sauravbasu8805]

Can it be made with cement ?

[@BitsOfInterest]

You can use the same materials as you use to build a fireplace, so fire brick and refractory cement. Those can get a little expensive, but if you plan to use it a lot it can be worth it. Edit: there is a link in the description to batchrocket.eu where you can learn how to cast a rocket stove.

[@howtogetoutofbabylon8978]

And why not make it a j-tube configuration so you can do vertical feed your firebox is plenty big for that you put a 10 ft piece of 2x4 and then feed about a foot an hour

[@BitsOfInterest]

I tried to stay close to the design and dimensions provided on batchrocket.eu for my first try. Maybe I'll make a J-tube some day, but probably first I'll try a bigger one, maybe with different materials like refractory cement. For now I'll be seeing how this one holds up. It does what I need it to, which is burn most of the sticks that fall in my yard 😁

[@johnbowen8969]

I think I heard another Rocket Stove guy refer to that same vortex as a Ram's Horn. It looks like one.

[@BitsOfInterest]

That's what I was going for, getting the gasses all mixed up down there and that it gets as hot as it can so that the exhaust is clean 👍

[@b.w.oostdam8875]

Quite a good desing with the ventury. However, I do not see how to use the heat in this desing for anything else but burning (efficiently) and maybe put a pot or pan on the exhaust. Could the section beyond the ventury not be a bit longer and the top of that section be made out of metal so the heat could actually be used ?. It is so insulated that it needs to have a way to use its heat more effectively. Maybe look at the oil-drum (upside down) designs over the stove to make a radiator ?

[@BitsOfInterest]

Thanks. This is mostly a prototype to see if it still works with the simplified shape and construction. You could use this shape inside one of those barrel heaters, though you may have to protect the barrel above the heat riser in some way because the exhaust fumes are still very hot and the barrel may burn out. I made it this shape and size because one day I want to build an oven/grill/smoker around it. It would be a metal frame with metal side panels and this would sit underneath to provide the heat for the oven. That would be another experiment to see if that will even work, haha. PS I did make the heat riser double the height in the follow up video (which helps it draft much better) together with some other improvements: kzbin.info/www/bejne/o3KvaqKBhqisnZo

[@JW-ol4cp]

Crappy idea. 55 gallon barrels are hideous

[@navneetkalra8067]

What mattirial you use

[@BitsOfInterest]

vermiculite board

[@peterbeyer5755]

Ceramic fibre board is a good alternative see Walker Stoves he has a great design.

[@BitsOfInterest]

Yeah, it's probably more durable than vermiculite. At the time I wasn't aware of this and vermiculite was half the price, that's why I went with it for this "experiment" ;)

[@peterbeyer5755]

@@BitsOfInterest the guy at Walker Stoves has collaborated with all the top rocket stove designers, Peter Vandenburge, Weaton, Earnie, he has experimented a lot, he is absolutely convinced that ceramic fibre board protected from abrasion by fire brick splits that can be replaced if necessary is the best option.

[@peterbeyer5755]

Also check out Himalayan Rocket Stoves his design is very similar to yours.

[@foxfish7115]

Hi, good effort so far, I also enjoy messing with rocket stoves. However it has been shown that even slight deviation from the established Batch Box design can have very negative effects on the very well sorted Peter Vandenburge design. That is not to say your design wont do what you want it to and only you can find that out. Unfortunately, if your design should prove successful then the vermiculite will have a very limited life span as it will soon crack and deteriorate! You can extend the life of the vermiculite by coating the surface with waterglass, this will help the lack of abrasion resistance inside the fire box bit not really help much long term. On a positive note, vermiculite is a great product to experiment with, even if it is not that cheap, it is a lot safer to use than ceramic fibre board. There are a couple of forums that have daily discussions on such subjects. I will look forward to any updates … good luck.

[@BitsOfInterest]

Thanks! I'm not under any illusion that my design will be as good as Peter van den Berg's experimentally proven design. This is why I did try to stay very close to the given parameters yet simplifying the design and construction a little. I wanted it to do better than the tin can and pile of regular bricks rocket stoves you see on KZbin which I think I already achieved ;) When I add the secondary air pipes I will also put an expanded metal grate on top to avoid the wood scraping on the vermiculite board. This will likely need to be replaced annually or so. Hopefully this will make it work better and last longer. Also I'm not using this one to heat my house; I'm just burning sticks that fall in my yard and need to be cleaned up anyway. I just love staring at those beautiful flames :)

[@foxfish7115]

If you like looking at flames you might like my vortex stove? kzbin.info/www/bejne/lXyTloSXYrZ4eLc

[@BitsOfInterest]

@@foxfish7115 Apologies, any reply with a link in it gets withheld automatically and I don't even get notified. At first I thought it was going to be some kind of pizza oven, but the window is to view those beautiful flames. I bet the seats on that side are in high demand 😁 PS You did comment I strayed a bit from the Peter van den Berg design, but you're not quite following his prescriptions either, are you? 😜

[@JW-ol4cp]

Peter V is a bull shi*t artist at best

[@ricardoclemente3255]

is that efficient? I mean, about the wood... doesn't it burn wood very fast? thank you

[@BitsOfInterest]

If you define efficient as getting as much energy as possible out of your fuel with almost no harmful side products from incomplete combustion, then yes 😉👍

[@andrewsolano9172]

also.....to keep it from cracking around screws maybe some pilot holes first then add the screws you need with a high heat adhesive

[@BitsOfInterest]

I did both those things. The problem was I only used the adhesive the second time I put the screws in and there wasn't much hold left. Like I say in the video, build it once, then burn it 😉

[@adriancho1742]

what glue did u use?

[@BitsOfInterest]

It's not exactly a glue, but I bought high temperature gasket cement to eventually create a door and seal it with a gasket. I also used this to fill the seems between the boards, but the screws provide the majority of the hold. You could also use refractory cement for this and it may even work better, but I've never used that before.

[@adriancho1742]

@@BitsOfInterest what is the name of the gasket cement?

[@BitsOfInterest]

I'm in the US so I bought "Rutland Stove Gasket Cement Black 10.3 Oz Cartridge" because the price and rating looked good, but you may have other options depending on your location. Here's the Amazon US link: www.amazon.com/gp/product/B000V4LTXC/ref=ppx_yo_dt_b_asin_title_o06_s01?ie=UTF8&psc=1

[@adriancho1742]

Tks. Just what I was looking for.

[@BitsOfInterest]

@@adriancho1742 be sure to wear gloves. This stuff is pretty nasty and will burn your skin and even corrode some tools. First time you open it you may get a big squirt of watery stuff coming out, that's why I have some black smudges on some parts after cleaning up the mess. I also had a bunch of paper towels on hand.

[@audiokees4045]

It is a big tent, not a small one. and the stove then also needs a outside build tower like a barrel in normal stoves.

[@BitsOfInterest]

I suppose if you have something like a yurt that could work. They usually also have a hole to put a chimney through.

[@audiokees4045]

@@BitsOfInterest there is no yurt, it is more like a bungalow tent, 4 x 6 meter when unfolded from the transporter. it is a transporter based system where the tent can be folded and unfolded when setup it. I need to make a secial opening through for the pipe, otherwise I get a burning tent.

[@unnikrishnannairkrishnannair.]

The flame must enter into the side of rising chamber to rotate. I have one 3yrs back

[@BitsOfInterest]

You could do that, but then the flames climb up the heat riser faster. For an efficient burn you need higher temperatures near the entry of the heat riser and you achieve those by making the flames spend (relatively) longer at the bottom. Additionally, as explained on batchrocket.eu the mixing between air and combustion gasses is also better with this more turbulent flow. That said, if you like to see flames spiral out of your heat riser by all means have them enter from the side, it looks great ;)

[@250tegra]

@@BitsOfInterest Thanks for all this! Yes, I spent most of a year playing with vortex generators and an adjustable heat riser stack. Both the offset entry and the vertical slot (rams horn vortices) do work, but you are right, the mixing and combustion efficiencies do seem to favour a fast vortex spin rate with a reduced net vertical flow rate - more stirring, longer time in the hot bit. Which makes sense. Peter's vertical slot seems best - the double vortices in the 'rams horn' have a higher spin rate (in my test rig) than the offset entrance (similar to Lol's earlier designs) when running at a similar vertical flow, which is what is desired. Your 45 degree entry to the slot is excellent thinking! We are moving house now, so very busy, will try to get testing again in the New Year!

[@BitsOfInterest]

@@250tegra Thanks! As I said in the video, most of my design is based on the dimensions and ratios provided by Peter van den Berg. I'm not trying to be smarter than the guy that did hundreds of experiments, just make it a little easier to build with cheaper materials. Hopefully before Christmas I'll have a video up with a door to keep the heat in the burn chamber and control the primary/secondary air better. We'll see what the differences are if I manage to build it right 😜

[@josheijnen732]

Finaly someone who uses Peter van den Berg's name the dutch way with a hard G 😄 When I copy you're mesurements I get a groundfloor of 15 x 45 cm is that correct? With 2,5 cm thick material my burnchamber will be 10 x 10 x 30 cm. Am I going wrong somewhere?

[@BitsOfInterest]

haha, thanks! That's a little Easter egg for Dutch viewers so you immediately know where the person who made the video is from ;) Before I overcomplicate things let me give the simple answer first: most boards are cut in half from 12x12 inch or roughly 30x30 cm material, except the bottom and top of the burn chamber because they need to be wider. I linked the Sketchup file in the video description in case you want to have a look for yourself. the inside of the burn chamber is 15x15 cm and roughly 27.5 cm long because you lose one material thickness at the back that surrounds the heat riser. The floor plan is 1/2 board + 2x thickness (15 + 5 cm) = 20 cm wide and 1.5 board or 45 cm deep. The inside of the heat riser is 10x10 cm (outside 15x15 cm so it fits inside the bottom part). PS if you're building just for fun while burning yard waste this size is fine, but it needs to be refilled quite often, maybe every 15 mins or so. If you plan on using it for cooking or heating you may want to consider making it a little bigger so it holds more wood, but the heat riser becomes taller really quickly if you try to stay close to the proportions on the spreadsheet here: batchrocket.eu/en/building. You may also need to use stronger, more permanent materials like fire brick if you go much bigger than what I have.

[@josheijnen732]

Ah, ik dacht al te maken te hebben met een "fellow Dutchman" 🇳🇱🌷 de omgeving leek echter totaal niet Nederlands. In de sketch up tekening zag ik geen afmetingen terwijl je ik in het filmpje sprak over halve elementen. Met de uitleg worden de afmetingen een stuk duidelijker Ik zat zelf te denken aan een metalen frame met daarin de platen, een p buis en een deur met glas. Dit dan allemaal iets groter en uitgevoerd als double box. Het materiaal is er voor gemaakt en niet te prijzig voor een experiment

[@BitsOfInterest]

Goed opgemerkt op beide punten :) Geboren en getogen in NL, wonende in de VS. In het geval je de Sketchup file download en opent kun je de "tape measure" tool gebruiken om lengtes te zien van punt tot punt, maar wellicht is dat niet langer nodig na de uitleg. Als je zit te denken aan een metalen frame dan is mijn tweede rocket stove video helemaal voor jouw :) kzbin.info/www/bejne/o3KvaqKBhqisnZo Als je een deur met glas wilt maken dan is mijn derde en meest recente rocket stove video helemaal voor jouw :) kzbin.info/www/bejne/n2m3eoCsgdyLbK8 Prijs is voornamelijk waarom ik ook voor vermiculiet had gekozen voor een ongetest ontwerp. Als je dubbel isoleert krijg je waarschijnlijk nog betere resultaten dan ik nu heb, maar ik vind +/- 1000 C boven uit de heat riser ook niet onaardig al zeg ik het zelf :p

[@lancerudy9934]

Why are you using screws?

[@BitsOfInterest]

I'm mostly a woodworker so I use screws and glue for everything. Please feel free to suggest better methods to attach pieces of vermiculite.

[@andrewsolano9172]

what would you think of casting our own boards made of vermiculite and or perlite with aircrete? i think it can be customized a bit better since its more insulative instead of radiative i think i would put metal or clay over firebox and i can cook on that too since most heat will be in chimney i would build some heat reclaimers....rocket stoves get hotter and of course with the secondary burn that it would not matter if we steal a bit of heat from this design.....it wouldnt cause any creosote at all.......in fact i could add a ceramic catalytic going right up the stove pipe....those dont work well with low heat but no danger of that here

[@BitsOfInterest]

Casting is always an option. Though if you're going to do it you might as well just cast the full shape, maybe in two halves. I was going for quick and easy, so I just bought vermiculite board. The vermiculite insulates pretty well, that's the whole point, to heat up the firebox and riser. I don't think you can cook on top of the firebox. I just put some sticks on top of it if it rained recently before I put them in to help them dry a little. I'm not familiar with heat reclaimers, but you can steal as much heat as you want in the riser above the port, it's all happening in the bottom of the riser. If you watched my latest rocket stove video you'll see it gets close to 1000C/1800F out the top, imagine what it is down below ;)

[@andrewsolano9172]

@@BitsOfInterest yeah interesting.....i think i may try to cast something complete or in 2 halves....i will find something to make a thick steel plate though for roof of firebox so i can use to cook or even put an ecofan on the good thing about rocket designs is that you can steal heat because they burn so hot no danger of creosote build-up like cooler burning stoves.....besides with the secondary ports should be mostly vapor escaping anyways not smoke

[@justtinkering6713]

I just found vermiculite board on amazon and it costs more than steel. Maybe firebrick would be better.

[@BitsOfInterest]

The point is to reach the highest temperatures possible to burn up all the gasses, so steel is not a great option. It tends to conduct heat quite well, so it cools the whole thing down. when you start insulating around the metal so it does get extremely hot again it will burn out. When I built this last year firebricks were much more expensive and they are also harder to shape. If you build a bigger permanent rocket stove and design so you don't need complicated cuts it may be an option. Vermiculite board you can just use woodworking tools with to get any size/shape you want. Fiber cement board may be sturdier, but it was twice as expensive when I was buying materials.

[@justtinkering6713]

@@BitsOfInterest okay, so your stove is meant for cooking and not radiant room heat?

[@BitsOfInterest]

@@justtinkering6713 this one is just for experiments to be honest 😂 but even if you would want the radiant heat you'd build the core (the only part I have) from high temperature materials like fire brick or fiber cement board and then you'd put a steel barrel over it to radiate out. Some even build a brick structure around it for thermal mass. Edit: mine is technically a rocket stove, if you search for rocket mass heater you'll find some awesome builds people use to heat houses. They are much bigger but the principals are the same.

[@justtinkering6713]

@@BitsOfInterest thanks, it's a darn good adaptation.

[@annemariekonijn2113]

It looks a bit like the rocket stove that was build years ago over here in our garden . It was build op with bricks. Guess who made it. ☺😎

[@andrewsolano9172]

who?

[@annemariekonijn2113]

@@andrewsolano9172 my son, Arjan, he is the one that build this one.

[@jamescad9978]

Ever hear of a down draft furnace? Easier to make then to light

[@BitsOfInterest]

Down draft is usually what you don't want? Sounds like going against nature to make that happen :p

[@richardgray2706]

I've made a few downdraft rocket stoves. Very easy to operate, but more tricky to light. In operation there is a steady flow of air down the vertical wood feed into and along the horizontal combustion chamber and up the vertical heat riser. New wood is fed by gravity into the combustion chamber, the draft down the wood feed prevents flames and smoke from leaking up the feed.. The combustion starts where the wood feed enters the combustion chamber and the air movement carries the flames along the chamber and into the heat riser where the combustion is completed. To light most downdraft stoves you have to first "prime them",. You induce proper direction of airflow by blowing or by bypassing the wood feed and setting a fire directly in the combustion chamber until the heat riser is drawing. This can be the tricky part.

[@BitsOfInterest]

@@richardgray2706 Ah, so you guys are talking about so-called J-tubes? I hadn't seen the term "down draft furnace" applied to them before. When I tried to look it up I just found actual home heating gas furnaces that use downdraft, LOL 😋 I did think about using a similar design as a feed mechanism for the wood, but what I did here was easier to make out of vermiculite board. J-tubes are mostly made out of steel tubing or firebrick, right? At least what I've seen so far.

[@jamescad9978]

@@BitsOfInterest The design I have come up with, but not built is of a plumbing y 6 inches cast iron, pipe running from the bottom of the y with a cap, the upper 45 to a chimney, a 6x3 bushing reworked to allow a 3inch pipe to run through it to almost the 6 inch cap, the 3 inch pipe is for feeding fuel and air to the combustion chamber, preheating both, the combustion chamber is between the 3inch pipe and the cap. the design would be set so that the chimney would point straight up, and the preheat area and combustion chamber are at a 45 degree angle. The hardest part is getting the thing lit.

[@BitsOfInterest]

This would be easier if I could see a sketch somewhere or a video, but I think I get it. You say you want the burn chamber to be 3 inch but the chimney to be 6 inch? Generally you want the burn chamber to be bigger than the chimney, so you could use the same design, just use it the opposite way. I have a 6 inch burn chamber with a 4 inch chimney and I'm already thinking how I can make it bigger, because it just burns up so fast... Metal is a great conductor of heat, cooling the gasses down, so you should think about insulating both the burn chamber and at least the bottom part of your chimney. If you have to use a 6 inch cast iron Y (they look very expensive) you could maybe do a 5 inch burn chamber and a 3 inch chimney with insulation between them and the Y. The insulation can be anything that withstands high temperature like ceramic fiber wool, rockwool or refractory cement. Last, I don't understand why you would put the chimney on the 45. Isn't it easier to stabilize if you did it the other way around? You could even extend the bottom a little and put a grate in so the coals fall down.

[@GabrielLopez-ml6tg]

Anyway to get dimensional drawings from you. The one that I was going to build will be steel. I would like to experiment on the concept of the vermiculite board. Great video on concept and test.

[@BitsOfInterest]

Thanks! It should be pretty easy to deduct the dimensions from the SketchUp drawing I showed. The burn chamber is 6x6x12 inch (150x150x300mm) and the riser tube is 4x4x24 inch (100x100x600 mm) when it's complete, just using half the hight now. Edit: measurements above are inner diameter. I know steel is more durable to move around, but do consider that it's not as efficient because you're just radiating the heat out instead of keeping it in for a better burn. Maybe you can line the inside with fire brick or vermiculite board somehow to insulate it. You'd have to protect it again with (replaceable) metal parts on the inside because insulation is very fragile. That's what my next video is going to be about that I'm currently working on. It will be a few weeks before that's ready. PS do you know of a good place to share SketchUp files? Maybe I'll create a Google Drive or something for the channel. I don't want to be sharing email addresses on here so we don't get spammed.

[@BitsOfInterest]

I finally created a Google Drive and shared the SketchUp file there. You can download it and open it with the free web version if you'd like: drive.google.com/drive/folders/1PVIpUuzQYxrEZtL_QHfcKIiIe9FMQnRP?usp=sharing

[@auttocarcom]

How about heating water

[@BitsOfInterest]

I'm sure that will work. These fires are a lot hotter than a regular stove, so it may be quicker.

[@auttocarcom]

@@BitsOfInterest Just trying to figure out the best way to incorporate some sort of water tank. Thanks

[@BitsOfInterest]

If you're just boiling water you can make some sort of metal frame to hold up a big pot above the fire, like cooking outside above a gas burner. If you're thinking about hot water for home use I've seen designs where they either incorporate a copper coil in the fire (may get too hot for copper though) or around the exhaust. The channel Little Aussie Rockets has done several builds (out of metal) trying to find the best way to heat water with a rocket stove.

[@-joe90]

💵💵💵💵💵💵💵💵

[@BitsOfInterest]

???

[@-joe90]

@@BitsOfInterest In my country each refractory brick costs 15 euros, multiply it

[@BitsOfInterest]

When I made this it was about the same here for fire brick or refractory brick that's why I used vermiculite board even though it's more fragile. I got a 2-pack of 300x300x25mm for $25 and used 6 boards/3packs in this video. Later I use another 2 boards to extend the heat riser, so in total I used 4 packs costing $100. It's not going to get much cheaper to build something that can withstand those temperatures.

[@-joe90]

@@BitsOfInterest thanks 👍🏻

[@GWAForUTBE]

Please wiki vortex. This is cyclonic. A vortex is much different

[@BitsOfInterest]

I'm just using the terminology that most rocket stove videos use, including the sources linked in the description. PS I'm not a physicist, but after Google/Wiki I'm not convinced vortex is incorrect per se. Edit: It's just two of them side by side. Feel free to link to a reputable source for the definition of vortex and cyclone. A comment with a link gets withheld automatically, but I'll approve it so it shows up.

[@timjansen705]

When Dutch people redo hillbillie stuff.

[@BitsOfInterest]

And do it better and as cheap as possible I may add 😜

[@j.j.maaskant7287]

Peter van de Berg is Dutch as well, isn’t he ?