DIY wood burner Pot Belly Stove. made from a gas tank

My Goal: To build a wood burning stove to heat my shed so i can still tinker in the cold winter months without freezing to death.

I had priced professionally built wood stoves and found very few under £400 most where about £600, so I decided to build my own stove using nothing but scrap metal I had lying around.

I bought my stove in at approximately £35.  so it is well worth the effort.

This is a job that must be done well to prevent fires or carbon monoxide poisoning etc so a good working knowledge is need or else seek advice from those who have the skills needed.

Its better to be safe than sorry when it comes to building a stove, so take you time and build something safe to use.

Materials needed are as follows.

1 scraped butane tank, i got this from a hardware store i once worked in, it had been a shop sign after it had failed as a gas tank. so this would be its 2nd time recycled.

3   1" x 1" by 1 foot long box section for the legs

1" weld mesh.

15kg fire cement to line the stove

Scrap  1/2" re-bar to make the grate.

about 6-8" of 3" pipe to make the

10mm plate steel for the hot plates (this may be the tricky bit, I was very lucky with this part)

1 3" 90* pipe coupling to make the flue bend.

1 broken brass dart (optional)

1 steel hinge.

3-4 foot of 20 x 6mm flat bar

A METAL handle for the lid, the wooden one in the picture scorched up and fell off.

I would recommend 4" pipe for a flue if possible.

Tools needed are Welder, Angle grinder with cutting, grinding and flap disks. drill plus the usual spanners hammers etc.

This is a project from a few years ago so i don't have ever part of the process photographed.

Thanks for looking.

Step 1: Cutting the gas tank.

I first started but removing the handles and the base ring from the tank and used a flap disk to smooth the welded seam round the middle of the tank.

I marked a line round the gas tank just about where the sides become parallel, I used a thin metal cutting disk in the angle grinder to cut the tank along this line,  this gave me the belly part of the stove and the lid.

A 3" hole was marked on the back of the tank about 2" from the top, The hole was cut out using a thin metal cutting disk to cut out this hole. this is where the flue bend will be welded to.

Comments

[streetrod5]

Dr Qui,
This stove was well-built, great job on the Instructable. I'm going to try this with an old propane tank (they seem to be wider than the butane tanks).

Do you think the stove is top-heavy? Would you recommend attaching it to the wall to prevent tipping? I was just wondering, as the base ring looks a bit small diameter...

[Dr Qui]

Can't believe it, after talking about the flew i went out today and the flew had disconnected, the pie had expanded and pushed the top pipe up in its brackets that are to tight to let it fall back down under its own weight once cooled. Typical of such situations just as i was inside the shed we had a hail storm and rain so i'm just going to have to hope tomorrow is going to be dry so i can fix it. I guess ill have to do that Ible i was talking about and i will bolt the stove down more securely as well.

[Dr Qui]

Thanks, I used the stove today for the first time in ages, one fill kept the shed so warm I had to leave the door slightly open, Im burning hardy any wood now since I insulated the roof of my shed.

Use at least 5" pipe for a flue or you will have a nightmare keeping it clean, don't weld sections of pie together as that will leave snags for crud to grow on and falling flakes to catch on, this is what happened to mine.

I have a new flew in now and should really do an Ible on it, shed in an awful state at the moment i post an Ible once i get it tidied up a bit.

Yeah the stove is top heavy and i have it screwed to the slab with some simple L brackets that are clinched over the bottom ring.  I was just going with the flow when i made this if i did it again i would angle the legs out and add feet that could be bolted down, at the time the ring just seemed obvious to reuse as the base.

What ever you do build don't forget the fire clay it makes so much of a difference, a friend bought a tiny little cast iron pot belly to heat his shed and the thing eats coal like mad needs feeding ever 20 mins and sits glowing red and goes out so fast if you don't set a timer to remind you to stoke it.

[Lowriderpr]

Wow very nice Job I love it!

[Dr Qui]

Thanks, wish it looked as clean and tidy now as it was back when this pic was taken, the red stuff keeps showing through due to use, but it keeps the place warm and that's what matters.

[sbrooke1]

One hundred and eeeeiiiiggggghhhtttttyyyyy!!! Nice one!

[Chief Cook]

(removed by author or community request)

[Dr Qui]

The gas bottle had failed inspection and was made into a sign for Calor Kosangas (the gas company) it was a sign for many years until it got to rusty to be used so it has been recycled twice.

The reject bottles have a hole drilled in them so they cant be used again and to let any remaining gas escape, when the bottle was cut open the inside was seriously pitted with rust.

I originally used the hole to attach a wooden knob, but the heat was to intense and it charred to bits in a few weeks and i replaced it with the metal handle.

[blkhawk]

Simply beautiful! A combination of art and a practical use. Kudos!

[Dr Qui]

Thanks, its still my favorite project to date. 

If building another i would put a door on the side rater than have it top loading as it can be smoky when loading up.

[Kevanf1]

Very nice, well done. I've been looking around the net for wood burning stoves made from discarded gas bottles and I have found a few examples. I shall probably make one with a front opening door taking your comments about it being easier into account. Can you tell me why you lined the inside with fire cement? I have not seen another gas bottle wood burner made like this with fire cement so am intrigued.

Cheers and take care.

Kevan, Staffordshire, UK.

[Dr Qui]

Thanks,

I lined the stove with fire cement for a number of reasons,

It protects the thin wall of the tank from direct contact with the fire (the old pot belly at the primary school i went to would often be glowing red from the heat) this will make the stove last for many many years compared to one that is not lined.  also reduces the risk of severe burns or the shed catching on fire.

It reduces the size of the chamber slightly so it take less to fill the stove.

It also hold the heat so you can light a  fire and let it go out and the stove will radiate heat for over an hour after the fire has gone out.

It took about 15kg of fire cement which accounted for about half the total cost of the build.  It is defiantly worth doing.

[Kevanf1]

Cheers Dr Qui. I wonder if there is an optimal thickness of fire cement to use then? Sort of in between too thin so that it cracks (does it, I haven't used the stuff for decades) or too thick so that it keeps too much heat in?

I'm also wondering about length of flue stack. Could it be angled at something like 45 degrees which would then present more of the stack inside my workshop and thus radiating more heat which would otherwise escape to the outside (wasted).

It might be interesting to coil some 15mm copper pipe around the flue stack too and have an at least 'warm' supply of water. Again, a way of possibly harnessing some of the heat that would other wise be lost.

Take care.

Kevan

[Dr Qui]

I lined mine with a about 3/4" on the sides and a little bit thicker in the base maybe about 1" to 1 1/4"

I welded mesh on the inside of the tank to give the clay a good key, its best worked in in lumps, trying to leave no air pockets, you will get some cracking and flaking but these can be patched up (i still haven't patched mine yet)

I am in the process of putting in a new flue (on hold as the weather is just to bad atm.) Im going up to 4 1/2"

I am thinking of putting sheet metal box around the first few foot of flue and ducting a fan through it to blow some of the excess heat out into the shed. to be honest a vertical flue gives of jst as much heat into the room and is much easier to keep clean.

I actually have a old warming box than belong to my grandmother that if fixed to the wall over the flue and has vents to draw the heat into the box, i hope it will still fit the new pipe. I will do an Ible when i get around to this.

you don't want to suck to much heat away from the flue as it will tend to build up with crud if it is running to cool. a friend had trouble with this on an oil fired burner but they seem to be affected more by this than wood burners.

one good tip is to buy a good quality rain hood for the flue, I got a galvanized one with built in bird cage for about £8.00. stops you shed from stinking of soot and ash after a real downpour of rain. you would be suprised how much rain can come down a 4" pipe

good luck with your build, post some picks when you are finished

[Kevanf1]

Thank you :-) I'll probably make a start on mine around next March or April. I have a couple of bottles ready so I'll use the intervening months to first remove the valves and then let the residual gases drain out. Obviously I'll fill them with water to ensure all the gas has dispersed too.

Good talking to you and yes, I shall do some pic's once it's up and running (and during the build of course).

Take care.

Kevan

[NutandBolt]

You made a realy great wood stove, When I made my stove I did a few mistakes very similar to the ones you mentioned in your ible. Where I didn't grind the old paint properly it came off under the high tempature. And I am still looking for some scrap flue pipe to raplace my current one that is too small. I priced new cast iron pipes in a few of my local hardware shops and I was amazed how expensive they are. Just to give price idea, the 45 degree part cost about 45-55€ so I will keep on searching for a scarp pipe ;-)

[Dr Qui]

Thanks, this is the most pleasing build I have done so far. I was checking out the stove you built you also did a nice job on yours I regret not haveing a front loading door as the top loader can be a bit smokey when you open it.

I will be replacing my flue soon, my bro is giving me some short lengths of 4" steel pipe he picked up as scrap some place he was working. I just need to get him to square the ends for me before I start. 

I'm going to make the flue in sections so it can be taken apart to be cleaned from the ground up

I checked into the price of proper flue pipe it was £35 per meter and I need at least 3mtrs to clear the roof of my shed, you should look into the price of 4" steel pipe or box from a steel fabricator.

Good luck with your flue rebuild,

Andy.

[bongodrummer]

Very nice! Is this what you burn your sawdust and paper logs in?

[Dr Qui]

Thanks, It will be once I get a better flue pipe installed.

Andy.