Gas Bottle Furnace

After making a Bowie Knife using the Instructable by Basta, who makes far better knives than I do, I decided that it would be useful to make a furnace, due to the fact that I melted our Kettle BBQ making the said Bowie Knife!

So, take one damaged, dropped off the back of a forklift, Gas Bottle and re-purpose it as a Furnace.

I told Basta, that if I did make a Furnace, I would post it on his "Instructable" but you know how it is, life gets in the way! So, while I'm sitting here in Spain, stuck due to the Corona Virus and won't get back to England until who knows when, I came across Basta's Knife instruction again and thought "I'm not so busy at the moment, other than washing my hands every ten minutes, as per Spanish and English Governmental instructions, I'll upload those photo's".

Supplies

Take one Broken Gas Bottle, buy one Mig Welder, look up on t'interweb on how to weld, re-locate the excess exhaust pipe never used on the Mazda MPV, one of those "it's here somewhere" items, I also knew that I had a set of Hole Cutters, came in handy, find anything else that can be re-used to help the project.

There were no plans, certainly no idea, just a desire to get it done!

Step 1: Cut Door Opening and a Little Bit of Health and Safety

Before you start to cut the Gas Bottle open you will have to fill the bottle with water and let it soak over night to expel all the gas that is in the bottle and has permeated the metal. This means releasing the gas and taking the valve off the top. Empty the water out the next day and proceed. Yes, I know people will tell you that they have drilled and cut a Gas Bottle and nothing happened, it didn't go Boom but why take the chance?

Luckily, i didn't need to do this because the valve on my bottle was cracked and bent to a 30 degree angle,

Decide how big an opening you are going to want and where it will be located on the Gas Bottle and mark it up, I used masking tape, now set to with the angle grinder.

As I was making the last cut, I realised that I should have made the hinge-side incision first and then made and welded the hinges in place, negating the need to line up the door, then make the other three cuts!

Step 2: Make Hinges, Locate and Weld

I made the hinges out of a piece of right angle that was originally anchor plates in a printing machine packing crate. I used threaded bar and nuts to space out the hinges before welding. Place the door in-situ and weld.

Not forgetting that I had only just bought the welder and was reading up, t'interweb again, and practising daily before embarking on this project.

Step 3: Door Handle and Heat Sink

A handle placed on the outer wall seemed like a good idea, just to keep the door shut and of a way to open it. So scrap metal was again cut and filed to shape and a heat sink, two different sized washers, was added, to be honest I should have taken more time over this and handled it better.

Step 4: Inlet and Exhaust Holes

A rear Exhaust and a right hand side Air Inlet seemed to be the way to go

Find the centre of the back, mark, centre punch, hole cutter to size of pipe.

Actually made this hole further down, not on top, so that the gases would would recirculate and be a cleaner burn.

Repeat on the right hand side for the Air Inlet.

Placed this as low as possible to force air in under the fire, this of course will be aided by the wife's hairdryer!

Step 5: Inlet and Exhaust Pipework

Mark up the centre line of both the front and back of your pipe.

This is important for when lining the pipes back up after cutting your 45 degree, right hand bend.

You might note that no Hi-Tec equipment was used here....

Step 6: Dampers

Dampers are important for getting a fire to perform as a low rolling heat or a raging inferno, coupled with Air or Forced Air.

These are sprung loaded and old keys are welded to the shafts to enable the desired flame and temperature.

Step 7: Lining Up and Fitting Pipework

Use the lines that you drew on the pipework, to line up the pipes and holes centrally and weld. You did draw the lines, didn't you?

Step 8: Up-pipe Clamp

The gas ran out whilst welding and the bottle was a perfect fit to make the clamp for the Up-pipe connection.

Cut a slice of the bottle off and split this length ways. Weld a nut to one side and a loose fitting off-cut of small pipe to the other, add a bolt through the pipe and use it as a draw bolt to close the gap and grip the Up-pipe.

Step 9: Fire Grate to Finish

This grate was from a council dump, a bit too big but with an angle grinder it was persuaded to fit.

Four bolt holes drilled through the body, of the Gas Bottle, nuts and bolts to fit, lay the grate on the bolts and push the Up-pipe down into the Exhaust outlet and you are ready to do a test burn and then spray with high temperature paint to complete.