loading
Want a D.I.Y. way to cook food WITHOUT using fossil fuel L.P. or having to buy charcoal? I know I did. That's why I built a "Rocket Grill"!
This is just one variation of a "rocket stove" - a simple appropriate technology for cleanly burning bio-fuels.

The rocket grill is fired by twigs, wood scraps, wood chips, or nearly anything else you can put in it. It naturally drafts air to maximize combustion. Once the the grill is really going, NO smoke comes out the top, only heat, and the grill really does sound like a rocket!

The grill is designed to not only grill, but also boil, bake, braise, and roast!

Because of the simple design and robust construction, it is nearly maintenance free. Unlike an LP grill, the burner will never burn and rust away to nothingness. (And cost good time and money to replace.) There is no piezo-electric starter or other "modern" technology in the grill, which would be prone to failure.

Despite how it looks, the grill is small and light enough for one grown man to lift into the back of a pickup truck. That way, it can travel with for camping or tailgating. (The lid and side tables are also removable for storage and easy packing.) Because it's covered and enclosed, it also qualifies for use as a "backyard fire-pit" in areas that do not allow open fires.

This project is mostly simple metal work. While it does require welding, it's pretty straight-forward. This was really my first-ever welding project.

So lets' gather together our tools and materials and get started!

Step 1: Tools and Materials


TOOLS:
  • Angle Grinder
  • Grinding disc
  • Cut-off disc
  • Welder
  • Safety glasses, work gloves, welding gloves, Welding helmet, hearing protection
  • Drill and drill bits
  • OPTIONAL: Laser Level, Bubble Level

MATERIALS:
This project is made mostly from scrap metal, but will need several other parts.

Parts for the Grill itself:
  • A Base. Something for the grill to stand on. Must be heat-proof. I used a scrap steel farm implement disc.
  • Steel Pipe - Diameter of your choice, but will effect cooking size and fuel rate. I used 6.5 inch diameter scrap steel pipe. About 3 feet in length.
  • Steel Water Tank. This becomes the "bowl" top of the grill and cooking surface area.
  • 4 x pieces of small diameter steel pipe, about 6" in length
  • 2 x 90 degree pipe elbows of same diameter
  • 2 x pipe flanges of same diameter
  • 2 x pieces of flat material that you like to make side countertop surfaces
  • Small scraps of steel plate

Parts for the lid of the grill:
  • A piece of wood, species of your choice, sized for a lid handle.
  • 2 x Carriage bolts (about 5" long) with matching nuts and washers. Stainless steel is ideal, as these will be exposed to both heat and the elements. Plain steel is fine, lower cost alternative.
  • 2 x pieces of copper or steel tube or pipe, slightly larger diameter and shorter length than the carriage bolts, to use as spacers.
  • The top end of the water tank.
Other:
  • Steel plate, about 6" side by 12" long. Perferations or slotted is ideal.
  • JB Weld
First, gather together your materials for the main section of the rocket grill.
  • Base
  • Large Diameter Pipe
  • Water Tank
The base needs to be large enough to keep the whole grill from tipping over. It also forms the very end bottom of the grill, which hot coals and asses will fall into. Any sort of steel plate would work fine. I found a piece of old farm machinery that fit the bill. It's a domed disc about 16" in diameter.

The large diameter pipe needs to be cut into two sections. Make one about 1 foot, and the other about 20" long. The 20" section will be the "vertical tube", and the 1 ft. section will be the "feeder tube"

That water tank that I chose was 16" in diameter. It was already cut apart from a solar water experiment I worked on. The bottom section of the tank is cut to about 1 foot tall. This becomes the cooking area "bowl" top to the grill. The water tank was also chosen because is is large enough diameter to fit my camping cast iron Dutch Oven, and a stock pot that I use for boiling corn.

Stacked up, the base, vertical tube, and water tank section should come to a comfortable standing height for you. The top of the water tank section is the height that grilling will take place.

To cut the steel, I found that an angle-grinder with a cut-off disc works best. I cuts quickly, without removing to much metal, and makes a nice, straight line. You could also use a reciprocating saw with metal cutting blade, or a plasma-cutter if you have access to one.

To mark a line on a cylindrical object like the pipe or water tank, wrap a straight section of sheet metal around it, and secure with masking or duct tape. Mark this line with a permanent marking pen, then remove the sheet metal.

Cut the pipes and water tank to length, using common-sense safety precautions. (Wear work gloves, eye and hearing protection, etc.)
Cut the top off the water tank, and save to make the lid.

Stack up the base, vertical pipe, and water tank section to get a feel for how your grill will look. If you ware working on a level surface, like a concrete garage floor, you can use a bubble level to make sure your vertical pipe is perfectly straight up and down. (Plumb!)

<p>Inspirational, and since I love welding, I'm very sorry I had the water heater replacement guys taken my old heater away! The fact that you can use any bio-matter is the really cool part. I have to buy special pellets or wood for my Traefer smoker / bbq-er.</p>
<p>awesome instructable, i cannot wait to build one. i noticed you said that when you grille it get more hotter in centre, is there a place(room) to put ceramic or some type of brick or coal that is used in gas grill to distribute the heat more evenly</p>
<p>I've done some modeling how to add air preheater to your rocket stove (but for flat pan on top):</p><p><a href="https://drive.google.com/file/d/0B0u4WeMjO894QmoxUkstazIwWVU/view?usp=sharing" rel="nofollow">https://drive.google.com/file/d/0B0u4WeMjO894QmoxU...</a></p><p><a href="https://drive.google.com/file/d/0B0u4WeMjO894eTRsLWdaX0packU/view?usp=sharing" rel="nofollow">https://drive.google.com/file/d/0B0u4WeMjO894eTRsL...</a></p><p>and cutted STL 3D model for reference:</p><p>https://drive.google.com/file/d/0B0u4WeMjO894dmdYVE85RGlNTlU/view?usp=sharing</p>
<p>Note small gap between pan bottom (flat for demo) and edge of innet rocket stove tube, and holes drilled in it's wall. Heat interchange plates will be hold pot upper, and trasfer heat to flowing air. All construction covered by larger outer tube with length smaller then inner tube. Air will go from bottom upwards.</p>
it'd be interesting to brew on one of these, boiling 5+ gallons always eats up a lot of propane.
<p>In any case, the idea of the cooking pan within the heat preserving housing is very good</p>
<p>I'm imressed by your post, and make Instractable itself: <a href="http://www.instructables.com/id/Samara-Gasifier-Backyard-Cooking-Stove/" rel="nofollow">http://www.instructables.com/id/Samara-Gasifier-Ba...</a></p><p>What do you think about adding air preheating into your stove ?</p>
<p>I like idea of gasifier stoves to put extra air to top of burning zone, preheated by flowing along walls of main burner. I have some idea to expand your design by extra tube goes around your burning column until your expand (cooking pot). Heated air can be feeded at top of column by holes, making smoke more clear and increasing heat power. In my case there is no visibe smoke at all, or (in case of gummy woodы like apple or especially cherry) smoke is almost white and without soot.</p>
<p>Expanding heating surface with heat transfer plates like here https://ligra.ru/Powerprofile/Ohladiteli1.jpg can make air flow more powerful and increase its injecting temperature.</p>
<p>Instead of fabricating what is basically a 6'' wye, do you think a cast iron 6'' wye from a plumbing wholesaler would work, or a6'' sheet metal wye in the heaviest gage available with a 6'' storm collar as the stabilising base would do the trick as both branches take off at 45 degrees.I realise that the 6'' sm wye would not be as heavy duty as your excellent design. This might save a lot of welding--just a thought.</p>
<p>I really like your stove. I'm working on one now. I don't like to put a hot lid on the ground so I am putting a hook on the underside of the lid so I'm able to hang the lid from the side of the stove. For getting rid of the ash, I'm thinking a one inch hole in the side of the bottom of the stove pipe. Just pour water down the stove and let it wash out, or just use a leaf blower to get rid of the dry ash. For a diffuser plate, I cut one inch tabs around the edge of a piece of round sheet metal and bent them like small fan blades. As the heat rises, it spreads and starts a whirlwind inside the stove body. Thank you for a great post. </p>
<p>Not to be off topic or anything, but just for a second there, it sort of reminded me of a piss tube in Nam, they were placed every once in awhile on most bases. Many had a sort of built up shield so you were given just a bit of privacy, however some were right out there in the open. I usually waited for one with some sort of shield. Modesty I guess.</p>
<p>Amazing. I've seen done for heat sources and the like but never a grill. I was looking at the heat output and that cherry red glow. It got me to thinking how this could be applied to the furnace design for a smithy forge. No bellows nor powered air supply needed - a smoke free rocket forge!</p>
<p>Very cool grill, I'm busy making a &quot;Franken-webber&quot; pizza oven and thought a rocket stove beneath would heat up the oven in no time. I made the rocket portion this morning and fired it up, got it sounding like a rocket in no time. </p>
Nice job.. I've built small rocket stoves but never thought of doing one this size. I'm glad I saw this because I have lots of stainless pipe in all sizes and I'm gonna start on one this weekend. I'll post pics and I have a few ideas on making it easier to clean. Also I have a great idea on the diffuser..pics coming soon..great job man..thanks for the instructable
<p>Damn, you're lucky, I wish I had some stainless steel lying around. I made mine out of scraps of steel I had lying around, looks a bit like Frankenstein's monster. Works like a beast though. </p>
If you have the material and welding ability to work with stainless steel, your project should turn out GORGEOUS. Many of my projects are either &quot;rat-rod&quot; or &quot;steam-punk&quot;, but it's great to see what people can do with different materials and skill levels!
<p>Have you considered cutting and sleeving the vertical tube near the base to ease ash removal? You could leave it as a lift off or put some set screws to secure it, like a Christmas tree base.</p><p>Great project!</p>
I like your grill a lot i'm going to make one but I'm going to use high temperature grill <br>paint just make it look better
<p>Let me know how the grill paint works out for you. Please share a photo when you finish!</p>
<p>I built one a few years back. I've never been able to get it to work though. My buddy who did most of the welding said he had it working but that was before adding the tank to the top. My pipe is a bit smaller and I actually used an old charcoal grill on top. Recently messing with it has come to mind as it's time to make it work or take it to the scrap yard.........</p>
<p>I love It! A steam-punk grill!!</p><p>Great job.</p>
<p>Just welded mine together. Still need to finish the lid</p>
<p>I like the base!</p>
<p>It is sweet, very heavy. it won't fall over but makes it a bit of a pain to move. gotta love trash reclaimed from work. This was all made from things that were either being thrown away, or recycled. didn't buy a thing, just cost me some labor and my grandpa made all the welds pretty for me.</p>
Neat. Not sure I understand the process of burning completely. Is wood fed from the top (is there a hole on the inside), or just through the feeder tube? <br> <br>Does the grill draught through the hole in the bottom (implement disk) &amp; out the feeder tube, or are other vents involved?
<p>Both wood AND air come in through the side tube. It is divided in half with a plate. The wood goes inside the side tube on TOP of the divider and air is drafted in through the same tube on the BOTTOM of the divider. The divider has air holes in the end of it for the air to get up through the wood (and the fire.)</p>
<p>Like the BBQ .Just a thought about Ash Clean up. Attached is something I made to clean out pipe going to my furnace. It is basically just PVC pipe reducers and then a valve with a quick connect to attach to an air line from your compressor. It is attached to the pipe with a coupler with 2 worm drive bands. I am not saying the person cleaning the ash is not going to get dirty but it still would be easier than trying to scoop out ash down that long pipe. </p>
Great JOB !!!! <br>I will make one soon <br>Thanks
That's really cool! Excellent the idea of grilling over wood, <br> <br>Could you just make some holes in the bottom and make the whole input pipe into a fuel holder ? So you could remove the ashes through the air holes, and more fuel would fit in.
The only thing that I could think of for why NOT to do that is that air-holes through the bottom might be a good place for hot coals to escape through or that perhaps they could easily get clogged with coals or ash.<br><br>So far, the divider plate is simple and works well. If anyone makes a variation of this project with the suggestion made by yummyribs, please post a photo and let us all know how it turned out!
can you up load video of you grill in action some ware please
Excellent work! I am inspired. <br> <br>I was curious...what did you do with the rest of the water tank? I thought it would make a good insulated base (fill it with vermiculite) between the grill and the disk. Of course, that would make the thing quite a bit heavier. <br> <br>Another idea for emptying the ashes would be to use a shop vac...if you have one. Of course, make sure the ashes are cold first! <br> <br>I am going to start looking for a used water tank.
this is fantastic. thank you for the inspiration! <br>
This is just too awesome!!!!!!! <br>Before reading this, I had never heard of a rocket stove.... <br>This is something that I would like to learn(welding/metal work) so that I could make a similar project. <br> <br>TY for sharing Sir!! 8)
bennelson!<br>Thank you very much for your ideas and your taste in expressing yourself through your words and your creations.<br>Enjoy your cobs!
Fantastic! Love the simplicity and effectiveness.
Where might I source the thick-walled pipe you used? I've been looking all over but just can't seem to locate 4-5 inch pipe with a thick enough wall. I'd like to build a very-long-life stove for our conservatory.
This was salvaged metal that was at a friend's house. I believe it was well casing.<br>Try looking at a metal salvage yard sometime, they are fun places to visit.<br><br>Since this project doesn't require new materials, the costs to build can be kept low.
Hmm i have always wanted to weld<br><br>for grilling certain woods are better than others for southern or mexican if possible use mesquite wood for grilling mm<br>although it might not work because there is little to no smoke to smoke da steak
What causes the &quot;rocket sound&quot; you referred to? Is that from the air drawn in from the bottom? If so, that could probably be mitigated by the airflow design.<br><br>A note of caution: I have seen many older water tanks of this type that are galvanized, which will emit toxic gases when heated, so try and make sure your materials are not plated; the galvanizing can be removed safely using different methods, but the effort is hardly worth it, since grinding it away also produces toxic airborne particles and acid treatments are hazardous in their own right.<br><br>Alternates to water tanks are decommissioned welding gas tanks, which come in either short, wide tanks or the more common thin style (making a smaller grill for a really compact outfit).<br>
So, I would feel more comfortable if someone confirmed this, but I'm pretty sure galvanized steal will have the galvanized part burn off after the first hot temperature. That's why I tend not to worry about the fact things do release toxic gases, because the first time I have a coffee can stove, grocery cart (galvanized steel), etc, I just burn it off in a very hot fire that I shortly step away from after starting up.
Even welding galvanized steel is problematic. It needs to be done in a well ventilated area, with a fan set up to carry welding fumes away from the operator. I'd certainly not use this grill for cooking food until all the the zinc has been burned away.
Yes. It burns off, or is reduced to oxide VERY quickly once heated. Stand well away, &quot;zinc fume fever&quot; is a work-related illness and is reportable !<br><br>Steve
The risks are mixed, but the simple answer is to not use galvanized material; if you wish to have a comprehensive view of the subject, I just found the following PDF available from a quick Google search for welding galvanized metal:<br><br>http://www.sperkoengineering.com/html/articles/WeldingGalvanized.pdf
There were not galvanized metals here. It was all bare steel, other than the water pressure tank, which was only painted.<br><br>The stove makes a pretty cool sound when it's really running full tilt. It's because of how much are naturally drafts through it. I wouldn't change that at all. I really like the way it sounds and how the air and fire travel through it.
Great instructable. This is a really great idea, kills two birds with one stone. I think I will have to make one of my own here soon. Thanks.
A great grill. How easy is it too get the ash out of the bottom, and what do you do with the ash once you get it out? <br> <br>It really is a major rocket stove. LOL
Originally, the base-plate had a hole it in.<br><br>When I would lift up the grill, the ash would fall right out the bottom. It also left nice little burned holes in my lawn! So, I welded that spot shut.<br><br>As it is right now, I just turn the grill upside down. It is lighter than it looks (without the side tables and lid) and I just dump it out into a steel bucket.<br><br>It doesn't make that much ash. One advantage of using fuel more efficiently is that there's less waste in the end.<br><br>I put some of the ash in my compost pile and the rest spread out in my brush pile.<br><br>I've played around with the idea of cutting a &quot;door into the bottom-back of the grill base, and hinging it as a place for ash-removal, but really, it's just so easy to tip the grill over to dump it out when I need to.<br><br>An ash clean-out would be a nice feature for a larger or more permanently mounted version of this project.
I don't know about the original one, but mine you just lift the stove off the little pile left after the burn. The ash makes a good fertiliser

About This Instructable

130,090views

702favorites

License:

Bio: Ordinary guy with no special skills, just trying to change the world one backyard invention at a time. See more at: http://300mpg.org/ On ... More »
More by bennelson:Medieval Coloring Book Princess Castle Bunk-Bed Wet & Underwater Product Photography 
Add instructable to: