Homemade Solo Style Fire Pit/Stove

I have been tinkering with homemade wood gasifier stoves made out of soup cans for hiking. It has been so successful that I decided to try making a large model in the vein of the Solo backyard fire pits that have been popular online.

I am not an expert on the physics of how these work, but in a nutshell a wood gasifier burns wood and channels superheated air to the ports around the rim. This air ignites the escaping wood gasses that usually drift away as/with smoke. When made and operated correctly these stoves produce no smoke and burn fuel efficiently, and pretty much completely...only powder typically remains if left to self-extinguish.

For this project I had a leftover helium tank from a birthday party to start with.

Supplies

Helium or Propane Tank

Steel Bain Marie Pot (found online or at restaurant/cooking supply stores)

Angle grinder with cutting and flap wheels

Drill and Bits

Step 1: Prepare Outer Container

I took an old empty Helium tank and marked a circle on the bottom that was the diameter of the Bain Marie Pot bottom. Using an angle grinder and cutting wheel I cut out the hole. I had to use a flap wheel to size it so that the entire Bain Marie Pot would slide all the way in with the lip of the pot sealing to the tank.

Step 2: Drill Vent Holes in Tank

Draw a line around the lower edge of the tank. Divide the line for your vent hole centers. I went with 32 holes for the "side rim" and 16 additional holes on the "bottom rim".

Center punch the holes. Drill pilot holes then make the vents with a Step Bit. I drilled the main ring to 1/2" and the bottom ring to 3/4".

Step 3: Drill the Burn Chamber Vents

Now you have to ventilate the bottom of the Bain Marie Pot and drill the gas vents in a ring around the top.

Much like with the Tank...draw your line and divide it for your hole centers. I made 36 gas port holes along the top. The bottom can be vented with any number, size or pattern of holes you desire, just make enough to get a good draft of air up through the bottom. Some people make these with a grate/grill in the bottom vs holes.

Note. These Bain Marie pots are Stainless Steel. Drill at low speed and with oil. It was time consuming (but obviously possible) with a hand drill. A drill press would have been easier.

I used alternating 1/4" and 5/8" bits for the gas ports and assorted (pretty much random) sizes on the bottom.

Step 4: Assemble

Now all you need to do is slide the Bain Marie Pot into the Tank till seated.

Step 5: Use

Fill the inner chamber with thumb sized (or slightly larger) pieces of dry wood up to, but avoid going over, the gas ports.

Light from the top. I use a cotton round dipped in wax or cotton balls smeared in petroleum jelly as starters.

Let it burn till you see the gas ports emitting tongues of flame. Once a bed of coals is established in the bottom it's easier to generate more wood gas by feeing in fresh fuel. Feed the fire gradually to maintain a balance of fresh wood and strong gas port burn. If you overfeed with fresh wood the ports may stop and you may get some smoke. Strong winds may effect performance.

Enjoy!

Comments

[Beemama]

What size/ quart Ban pot did you use?

[buydor]

How stable is it? I've a couple of these helium tanks and was in the process of converting one to a light weight fire pan and the other something similar to this. I've concerns something taller might be a little unstable.

[tgace459]

At the size I have it's very stable on a flat surface. I use a tile block on grass.

[merxth]

Hi, thank you for posting. Did you have to do anything special to make sure that the tank was totally empty? I have always wondered with any Instructables that use propane or helium tanks for projects. Thanks, graet post.

[joe.m.cope]

My grandpa taught me to fill a propane or gasoline tank with water if I needed to cut, grind, or weld on one. No air = no explosion.

[ferball]

I use old propane tanks all the time. Open the valve to relieve any pressure, and with the valve open remove the valve assembly. Then fill the whole thing with water. I usually let it set with the water in it for a day. Then I pour it all out and fill it up again. After I drain it the second time it's ready to be repurposed.

[Yorkshire Lass]

Helium is inert, so not a problem. I have made a woodburning stove from a propane cylinder. I opened the valve fully (I couldn't get it off) and, because I was in a hurry, just shook the cylinder from time to time all day in the open air. When I came to cut the valve off with an angle grinder I was careful not to stand in front of it, but I still ended up with a sooty face from the small explosion as the residual gas ignited. Much better to leave it outside, upside down (propane is a little heavier than air) with the valve open for weeks, or knock the valve off and fill it with water.

[tgace459]

I just opened the valve on the helium tank and left it outside for an hour before doing anything to it.

Propane is far more flammable. I'm no expert on those tanks, but I would guess you would take it out to an open area and open the valve and let it sit for a while. If I was using a propane tank I'd wrench the valve clean off once I thought it was empty then let it air out for a while longer.

[JFC1978]

What size pot insert did you use? This looks like a perfect project for my family's upcoming camping trips.

[ferball]

I just made it with a propane tank and a 4 gallon steel milk bucket. The milk bucket fit perfect.

[tgace459]

I want to say it was an 8 quart. I actually just went to a restaurant supply store with a tape measure and picked one that matched the size of the hole I cut (approx...I had to grind it out to fit).

[seamster]

Very nice. Thanks for sharing how you made this, I might make one sometime!

[tgace459]

Thanks!