How To Make A DIY Cobb And Fire Brick Rocket Stove Forge

In my how-to quest for the best DIY rocket stove, I make a big cobb and fire brick rocket furnace.
Check out my flat-pack camping rocket stove on Amazon: amzn.to/2ZtMdVi
My goal for this furnace is to melt aluminum cans using a graphite crucible. I love rocket stoves (of various kinds) because they use found-fuel, sticks and twigs, a sustainable and renewable bio-mass fuel source, which is also carbon neutral.
For this rocket stove, which I am calling a furnace or forge (also MAX), I've used a cobb chimney contained inside a 13 x 13 inch flue pipe. The flue pipe protects the cobb from eroding and the cobb insulates the flue pipe from high temperatures. The chimney sits on top of a fire brick fire box with a paver surround.
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[@cecilarchie4112]

Nice job, I really enjoy watching your videos Mr. GreenShortz, thank you for taking the time to do them.

[@GreenShortzDIY]

Thanks for saying so, Cecil. I appreciate knowing. Thanks for watching.

[@armandomanzano5101]

You did great sir! Thanks for sharing your ability to do that practical fire box. God bless you! From philippines

[@augustinmladin5554]

You are getting better at what you are doing.Inspiring .Thanx

[@Environmenthrall]

Just started watching some of your videos the past few days, and saw you let the ants escape as best as you could. You're a good dude.

[@GreenShortzDIY]

Ha. Yeah, I tried to chase out as many as I could. I like to share the yard with the local critters. Thanks for watching.

[@josephinehogg3629]

AWESOME! lost for words. what a fantastic concept through to construction. well done

[@GreenShortzDIY]

Thanks for watching Josephine and for the encouraging words.

[@MrAdamNTProtester]

Very cool low tech build... love it thanks!

[@stevefranpimblett8257]

This is absolutely brilliant. I was gifted a pile of refractory furnace bricks and I am going to make my very own "Max" cept I am going to call him Herman and every time I use him I am going to send over awesome karma vibes in your direction from Tasmania. Thank you SO much for sharing this tutorial!

[@josephinehogg3629]

hi Tasmania from Lismore, Northern NSW! It's nice to see another person from "Down Under" finds GreenShortz amazing as well :)

[@GreenShortzDIY]

G’day to you both. More power to you Steve. Would love to know how your build goes. I’ve spent a little time down under myself (Sydney, Darwin, Alice Springs and a Drive over to Uluru. A beautiful land and people. Thanks for watching.

[@rodilflancia2149]

Nice.... patience really works!

[@wildabezet860]

A notification for your video popped up on my iPhone and I decided to to watch it. Just watching your thoughtful planning, use of natural materials, and problem solving skills, is very intriguing. I’m not planning to melt any aluminum, but I might be interested in an outdoor bread baking oven or even a kiln for firing pottery. Watching you mix cob was pretty amazing. I’m sure it’s an ancient skill. I also noted the comment about the use of perlite. Thanks for an interesting video and the food for thought.

[@GreenShortzDIY]

Thanks for watching. I think this type of stove would work as a kiln, but not for bread. I did make a bread oven out of cobb as well. You can check it out here. It is quite different than this rocket stove, but uses the same material. kzbin.info/www/bejne/j2ncoYKsfdB_f7s

[@bc-guy852]

Wow Tom another great video!! Your designs are getting SO creative - this one was cool, (pun intended). I so like that you are truly using local materials and so often utilize other stuff that would be headed for the landfill. Great stuff!

[@gwenstrong1724]

Use your dryer lint as a starter also. Works great!!

[@jackbquick123]

Cobb? When I was 4 I called it mud pies ☺ great video! I think I will try to make this,, thank you and God bless

[@GreenShortzDIY]

Ha! I made some mud pies too in my day. Hope the build goes well. Thanks for watching.

[@4ngelo213]

You're a great teacher, thanks for making this video

[@GreenShortzDIY]

Thank you, Eric. Thanks for watching.

[@jurandesouza69]

@@GreenShortzDIY 0lk

[@AlternativeHomesteading]

Excellent presentation and design. Thank you for creating this video for us.

[@GreenShortzDIY]

Thank you for the kudos and for letting me know you enjoyed the video. BTW...I am ADD, but have come to see it as a blessing...connected directly to my creativity. I refer to it as having a Ferrari brain with bicycle brakes. :-) Thanks for watching.

[@AlternativeHomesteading]

@@GreenShortzDIY ADD, ADHD are diagnoses utilized to isolate, label and medicate people who are energetic and think quickly. It is a contrived disease" comprised of a variety of desirable qualities. :-)

[@GreenShortzDIY]

@@AlternativeHomesteading Agreed. Our highly structured schools don't know how to manage the active learners and thus label them with a double negative of "deficit" and "disorder." My mom was always advised to medicate me and she refused. :-) Thanks for the reply.

[@lucadelmare5542]

Amazing … bless you

[@cpd833]

Very nice build. I am interested in knowing how well it melted aluminum. I currently use a charcoal forge for aluminum melting and it is small and costly to run. I like cheap fuel. Thanks for all your work in putting diy stuff together.

[@thechimneyboys4990]

Loved the video. Very entertaining!

[@sumakwelvictoria5635]

Sheeesh. Having extreme clay envy. You are sitting on a clay mine! Gold for a clay products manufacturer! Good for you! Pottery makers are probably salivating at the clay mine! Hehehehehe.

[@GreenShortzDIY]

Lol. Not quite pottery grade, but is nice to have an extensive supply of a building material just below the surface. Thank you for watching.

[@godislove201]

It looks like you're really getting a handle on the Cobb mixture... Good job!

[@GreenShortzDIY]

Thanks Eddie. I am enjoying working with cobb. I've got a few more projects in mind before it gets too cold to be barefoot in wet Georgia clay. :-) Thanks for watching.

[@henriponzanelli2376]

Très beau travail, merci pour le partage

[@GreenShortzDIY]

Merci d'avoir regardé et pour les encouragements.

[@miriamallende817]

Bellísima estufa ....yo quiero una ....muchas bendiciones y gracias por compartir

[@table4glasses]

"I now pronounce you chimney and fire box. You may kiss the mud!" LOL this part had me cracking up. Great video!

[@GreenShortzDIY]

Ha! I’m glad you get my twisted sense of humor. I love that I can be myself here on KZbin and bring a little chuckle to someone’s day. Thanks for letting me know you enjoyed it. Thanks for watching.

[@peziki]

Your skills with camera and editing are excellent. Also the narrative and audio is well done. Very educational and entertaining. I'm thinking of trying a chimney flue as part of a rocket stove.

[@GreenShortzDIY]

Thanks for the encouragement and feedback. Make sure your chimney flue has an insulating liner, like cobb. Because the flue pipe is just vitrified, it can't handle the intense heat directly. Good luck with your build.

[@bossdog1480]

Great video, very interesting and entertaining. If you experiment with blocking the air supply partially you can make it draw harder.

[@GreenShortzDIY]

Thanks for the tip, Boss. I'll have to practice with some dampening. Thanks for watching.

[@iwantcheesypuffs]

Excellent video. Nice modern build of the ancient pottery kiln [ about 5 thousand years old ] -- now called a "rocket" stove. Great use of your local natural resources and reusing materials. well done! Would like to see you use it as a forge or some crucible use as well

[@GreenShortzDIY]

Ha! True. The ancients had an amazing understanding of how to use fire. We just re-brand and call it new. lol :-) Thanks for the feedback. Thanks for watching.

[@MrSeebobski]

Nice build. One thing I see is to extend out a firebrick's length could help the draft as flames are at the entrance. If you have a few more it's worth a shot.

[@GreenShortzDIY]

Bob w Thanks for the suggestion, I think it might need more draft power. I tested it with crucible in (video coming soon) and it needs better airflow. Thanks for watching.

[@richardsolomon8076]

Great video Tom looking forward to seeing the crucible with liquid aluminum, and awesome to see Chris looking to promote your stove :-) great video team

[@GreenShortzDIY]

Thanks Richard! I’ve done an initial test (video coming) and I think it’s going to need some mods to burn right with the crucible in. And yes, cool to get the message from Chris. :-)

[@fredvanolphen2953]

Thanks for the great video. That weed is Microstegium vimineum, commonly known as Japanese stiltgrass and yes, there's always more where it came from since it's an invasive noxious weed. But It's perfect for the job because it's very stemmy and strong even though the stems are thin

[@GreenShortzDIY]

Fred, thanks so much for sharing the name of the grass. It is definitely invasive. Thanks for the feedback. Thanks for watching.

[@johnpatric7041]

☦️ excellent; job I watched ful video.👍🌹God bless you. Very hard-working man . keep it up, well-done !

[@edlibey8177]

Ah. I was totally confused. You called it a forge but, it’s really a foundry. Big difference. Love the build. Look forward to seeing you melt aluminum. I burn some old two by fours in my giant pile of blocks masquerading as a rocket stove . Ran into the same problem. I can burn a two by four if I mix in enough big round wood. I have some old pallet pieces so it is nice to burn these.

[@GreenShortzDIY]

Hi Ed. Thanks for the correction. Please explain the difference for my benefit. I couldn’t tell you. I make masquerade rocket stove as well. I’m in good company. :-) Thanks for the feedback and thanks for watching.

[@mohmedmansooor488]

Very well brother... thank u

[@victoryfirst2878]

I can tell you were a grape crusher in the past. The rhythm is just right on. Keep on doing great work too.

[@GreenShortzDIY]

Ha! I bet grapes feel different between the toes than cobb. :-)

[@nikhilvenugopalan7904]

Am a great fan of uuuuuuuu.i love u bro.

[@jamaics07]

Nice build brother this rocket stove technology really has few limits on what it can be used for so efficient I’m a new subscriber to your channel, very inspired to continue working on my own channel . Great work keep It up !!!

[@emaglott]

Great video! Inspires me play with cob for building stuff. I love all the reclaimed material you use! Oh and I believe that weed is Japanese Stiltgrass, an invasive species.

[@byronrolandopalaciosmarroq4533]

Es lo mejor, que he visto, y por muchas razones, espero poder hacerla muy pronto, gracias, y exitos.

[@GreenShortzDIY]

Gracias por el cumplido. Y gracias por mirar. Planeo hacer más videos sobre esta estufa.

[@nrtastic3885]

The chimney is essentially a cross between cob and rammed earth, I dig it.

[@GreenShortzDIY]

Thank you.

[@d.slater3958]

a forge that I can use would be so cool. I can't wait to use my powerarc to make one. I want to use an old gas cylinder.

[@GreenShortzDIY]

Hi D. I think your gas cylinder idea would handle the heat better than the flue pipe. Especially for the the high heat of a forge. Thanks for watching.

[@DropForgedSurvival]

*We love your Rocket King Camp Stove Design. We decided to want to introduce it to our epic loyal fans on our channel*

[@GreenShortzDIY]

Cool. I'd love to know more.

[@GreenShortzDIY]

Just checked out your channel. Get me your address and I'd be glad to send you one to review. :-)

[@DropForgedSurvival]

GreenShortz DIY Find us on Facebook and Shoot us either an Email or PM

[@richardsolomon8076]

Wicked cool

[@GreenShortzDIY]

Will do.

[@saltybildo4415]

That is cool brother

[@GreenShortzDIY]

Thanks for watching, Bill!

[@HomeBibleCollege]

Great film. Try using ash if you can get hold of it and dont think of trying to get full heat until the rocket has become completely dry. This might take a week of burning. Another thing is that wood burns better on a flat base like concrete this gives airflow over the wood which is better. By the way l love how you used cob. That was brilliant.

[@budpratt4295]

I like the forge rocket stove.

[@GreenShortzDIY]

Thanks for watching, Bud.

[@jovyfelisilda7808]

Nice

[@mohammadshah2766]

Great

[@user-nc5zz7nw8u]

Thank you.good

[@bluepen61]

Fwiw, we make firestarter using paper egg cartons, dryer lint, and wax. Very good video!

[@GreenShortzDIY]

Thanks for sharing your idea, John. I’ll have to give that a try. I have easy access to all three. I’ll just have to get the next dozen eggs in paper. Thanks for watching.

[@usmcdaddysteve3623]

You got a go to cobb ratio recipe

[@auttocarcom]

What about a bigger fire box? but same chimney?

[@snbtt3354]

Love it 👍 imagine archeologists unearthing the mug bits in hundreds of years, what will they think 🤣

[@GreenShortzDIY]

Ha! I hadn’t thought of that. Thank you for watching.

[@rocktroll2002]

I wonder if a j tube feed would help you maintain heat you need to melt aluminum?

[@GreenShortzDIY]

You might be right. I have tested this (video coming soon) and I don't think it will melt the aluminum on its own. I've been wanting to add a proper J-tube to one of my rocket stoves. This might be a good opportunity. Thanks for the suggestion.

[@koslisted9458]

Anyone tried mixing Perlite into the cob, like in some of the Rocket Stove's I've seen on here? Wondering how well this Foundry held up and what metals you were able to melt too.

[@sajuantony7521]

I am saaju from kerala India very good ldea👍👍👍👍👍

[@GreenShortzDIY]

Thank you for watching, Saaju.

[@MrDkgio]

I really want to see your indoor shed now 🤪

[@GreenShortzDIY]

Ha. Semantics. Thanks for the laugh. Thanks for watching.

[@MrDkgio]

GreenShortz DIY thanks for the videos👍

[@davel9015]

Buy a gallon of the cheapest vegetable oil you can find, then dip your kindling in the oil for just a second or two before lighting. Makes the job easier but is safer to have around than lighter fluid or kerosene. (Great for starting cooking charcoal, too and it won't make your food taste like kerosene.) Love your posts BTW.

[@aprendicesautodidacta24]

Oye , puede diseñar una de ladrillos para que funcione dentro de casa ? Pero que no deje humo ?

[@DataSmithy]

A lot of people build rocket stoves out of uninsulated material because they're easier and faster to build. but the original rocket stoves were all insulated, especially the chimney. Insulation means less heat is absorbed by the building materials, making the combustion process hotter and cleaner. If you really want more heat to melt stuff, use *insulated* fire bricks and insulated chimney. For example mix clay and perlite to make an insulated cob mix. Using insulating materials you should be able to get well above 1500 degrees, possibly even above 2000.

[@GreenShortzDIY]

Hi Douglas. Thanks for the input and suggestions. I thought about perlite. I had a bag sitting right there. :-) I plan to make some insulated mud bricks, trying some different methods. Perlite. Sawdust. Aircrete (minus the mud). Any other suggestions? Thanks for the the feedback.

[@dlwatib]

High straw content should do the trick. Straw is an excellent insulator. Use just enough clay and sand to make a workable binder.

[@Simonas.G]

What about 5000? Lol!

[@seiltongoncalves424]

Parabéns valeu 🇧🇷🇧🇷🇧🇷🇧🇷👍✌️

[@dasnvps]

I am curious if you can get a temperature hot enough to melt it soften that rebar under the crucible?

[@GreenShortzDIY]

Dustin that will be something to watch for. I’ll certainly be doing some testing. Thanks for watching.

[@HealthSupercharger]

Your stove with that enlarged hole would be also great for higher efficiency cooking with a pot as the wind does not blow your heat away.

[@addisababa1835]

That brownish stuff that you are using as a morter , what is it and what is that made out off and how do you do it please ?

[@GreenShortzDIY]

Hello. That is a mixture of clay and sand and straw. It is called Adobe or Cobb. The clay is actually the native soil here in Georgia. Thank you for watching.

[@danfaller1089]

Pine cones are a good starter

[@GreenShortzDIY]

Good suggestion Dan. Thanks for watching. My next video is actually 11 ways to light a rocket stove...but it won't have pinecones, because it is already filmed. However, I am planning an alternative fuels rocket stove video and I'll include your idea (and comment). Thanks for watching.

[@carlosgermansanchezlizarra9629]

EXCELENT JOB , BROTHER , I LIKE YOUR IDEAS AND YOURS VIDEOS , THANK YOU , SEE YOU LATER BE FINE

[@GreenShortzDIY]

Awesome, thank you!

[@cayleesmith1440]

about how hot does this get?

[@Mellodeath21]

My forge is a bit smaller and I can maintain temps of 1400+ F. Just takes about 30 minutes to preheat it.

[@unoken1]

Have you seen the rocket mass heater by the Honey Do Carpenter on youtube built with aircrete?

[@GreenShortzDIY]

Hi Ken. I have. Are you talking about the one he made for Dirt Patch Heaven? I know he’s made a couple. I am practicing with aircrete right now. Videos coming soon. Thanks for watching.

[@debleetwo]

What happened to the weeds/straw you were supposed to put in the cobb (cob?).

[@debleetwo]

I spoke too soon.

[@gm2407]

Is your rebar still in place or has the heat from the stove reached tempratures hot enough to affect it possibly melt it?

[@GreenShortzDIY]

I haven't used this enough to know if it will melt the steel. My gut says no, because I haven't be able to get it to melt aluminum. Thanks for watching.

[@HealthSupercharger]

No way he could get steel to melt. Aluminum is much lower temperature.

[@jovosedlar]

@@GreenShortzDIY try closing and or reducing the feeder of the stove so all air would come thru the bottom grill Love how you built the ash area roomy so ashes cant clog the air intake

[@johncourtneidge]

Hurrah! Here in the UK, accessing any materials (even found clay, sand, fibre) is just about impossible: the Thieves (aka The Landowners) have stolen everything. Ah well.

[@rhiantaylor3446]

I was just wondering how long you would need to leave it for the cob to dry naturally, weeks or months and then you lit it :)

[@GreenShortzDIY]

Ha! It would probably not crack as much if I let it dry naturally. One benefit of the cobb inside the flue pipe is that I I can replace it once it fails. Thanks for watching.

[@jovosedlar]

@@GreenShortzDIY or just patch it where it cracked with more fresh cob

[@bobbiecoles629]

How to keep busy during this COVID-19 Pandemic.

[@juboo1234]

Wonderful work! Love you! That music is way over board.. 😒I dont always have free hands to keep adjusting...

[@GreenShortzDIY]

Thank you Judy. I've chilled out on the music lately...to tried to. :-) Thank you for the feedback. Thank you for watching.

[@mix_t.v6894]

Hahaha like a chimney of oldship

[@bobbyeury1458]

Ike to see it melt can

[@ariefdotcom]

waduk pisan

[@RassMass]

YOU FORGOT THE SAY THE TRAIN IS HERE AT THE SOUND OF THE HORNS ROARING HAHAHA

[@GreenShortzDIY]

Ha. True. I figured people know the deal now. :-)

[@chxzniu_x6995]

Crear job

[@GreenShortzDIY]

Thanks for watching.

[@user-lj6er4tu7w]

good 저도하나 만들었어요

[@j-wonkim1257]

우연히 들어왔는데 반가운 "안녕하세요"

[@GreenShortzDIY]

시청 해주셔서 감사합니다.

[@johnzillner1596]

Three 5 gallon buckets of sand, harvested with a cup ! LMAO Next time man up and use a thimble ! LOL No for realz though, great video, I really admire your sand !! Keep up the good work.

[@GreenShortzDIY]

:-) I used a shovel in a recent video. It was faster. lol. Thanks for the laugh. Thanks for watching.

[@aurelius388]

You remind me of Hank Schrader in Breaking Bad.

[@bigtopmedia]

That’s an interesting comparison, why?

[@abdalbateeh6766]

👍👏

[@TheRojo387]

Calcium orthosilicate makes for excellent firebrick material.

[@GreenShortzDIY]

Thank you for the suggestion. I will research. Thank you for watching.

[@TheRojo387]

@@GreenShortzDIY You know how sand doesn't dissolve at all in water? NOT TRUE! A minute amount DOES dissolve and react with the water to make orthosilicic acid, one of two components you can use to synthesise calcium orthosilicate at home. The other is quicklime.

[@nrtastic3885]

your cob needs a little more moisture, it helps with molding, mixing, and helps the clay become more cohesive reducing the number of expansion cracks that will form over time from the expanding and contracting heat.

[@GreenShortzDIY]

Thank you for the tips. Thank you for watching.

[@HealthSupercharger]

If the temperature is not going to be high enough to melt aluminum then add a waste oil drip system into the fire, I have seen guys on youtube with metal rocket heater reach 50 to 100% higher temperatures than wood. Oil is also free. Just in case the blower does not work.

[@KOJIRO44]

24:22 se escapa el escargot

[@arbluetick]

Use a buddy round with a two by four piece of wood. They burn together

[@GreenShortzDIY]

Brilliant. Thanks for the tip Aaron. Thanks for watching.

[@samanthanicholson9015]

Did it work, of so how long to melt aluminum?

[@GreenShortzDIY]

Hi Samantha. The stove burns great until the crucible goes in. Then the airflow was greatly hampered. I did make a video of this test, with the not-so-great outcome. I will make some modifications and retest. I'm optimistic that I'll be able to melt some cans. Thanks for watching. :-)

[@samanthanicholson9015]

@@GreenShortzDIY wouldn't it get more air flow with a taller crucible , not a wider one?

[@GreenShortzDIY]

It would have better airflow, but the crucible needs that wide base to capture heat too. I think it’s probably easier to adjust the mud stove versus finding another crucible. Although your question reminded me that I have a smaller crucible that might work also. Thank you.

[@samanthanicholson9015]

@@GreenShortzDIY the reason for the questions is that I hope to make a kiln this way for jewelry clay pieces. Let me know how it works:0)

[@shaddec55]

Thus far, I've seen none of your past videos feed on to the next one. That's really aggravating. Can you number them, so people like me watching past projects can see what happens next? Thanx!

[@GreenShortzDIY]

Argh. :-) If you watch them via my playlists, they will be in sequence. Although, I can’t guarantee my brain has made them in a straight line. Lol. Thanks for the feedback and for watching.

[@tukangchannel488]

you got subscribe from me..

[@bradleychilds4387]

Your clay is a deeper red than ours, ours is nearly yellow in places

[@jandieolivares8593]

ITS REALLY NICE MY QUESTION IS SO TALL TO COOK IN??? DON'T U THINK THE SMOKE WHEN U BURN FOR THE FIRST TIME IS TOO MUCH?? IT'S AFFECT IN THE PLANET EARTH..

[@dalehatfield5637]

Thats Stilt grass an invasive

[@alcohol_soju_drunk1218]

우와

[@GreenShortzDIY]

시청 해주셔서 감사합니다.

[@belajarbikindiy1690]

Good job dude.. Lest come to my first video.. Thanks

[@michaelanderson9792]

I wonder has anyone use bamboo strands in concrete?

[@GreenShortzDIY]

Oooh. That sounds like an interesting idea. I bet it would work. Thanks for sharing, Micael. Thanks for watching.

[@malleusmaleficarum9248]

4:46 In most spa resorts, you have to pay for this kind of pleasure ;)

[@GreenShortzDIY]

Ha! I agree. Stomping cobb is very relaxing. Thanks for watching.

[@douglasfrederick9232]

Try using a blowpok instead of just blowing on the fire - really like watching

[@GreenShortzDIY]

Thank you for the suggestion, Douglas. Thank you for watching.

[@unravel523]

Great video- must be kinda cringy to watch for Craftsman though ;-)

[@meeranmaideenjalaal5625]

Thanks late pick up. But HiFi speed

[@GreenShortzDIY]

Thanks for watching, Meeran.

[@meeranmaideenjalaal5625]

@@GreenShortzDIY .Thank u very much

[@frederickastilla1018]

I think you forgot the vent on top. If you put the pot on top, there will be no air vent.