Fire - Quicker, more durable ethanol stove

A while back I made a pretty convincing ethanol camp stove out of a coke can.

It worked well and looked like this when it was running.

I've used it a bit since then and it's definitely a practical addition to any backpack.

The problem is it's starting to show signs of aging. The can expands and contracts, and there is now a crease where extra gas flows giving an uneven flame.




In my model (also not my design) I used an inner sleeve with holes at the top to let the gas out. The result is that the trapped ethanol (spirit/alcohol/methanol) between the outside wall, and the inner wall boils the spirit, and creates a gas jet that looks a lot like a normal BBQ burner.

One of the problems was trying to get the top of a coke can to fit into the bottom of a coke can. It's tricky because (of course) they are the same size. It can be done, but involves gently stretching the outside one and it takes a lot of messing about.

Now I'm being pretty fussy here. The little burner works really well, but it did tend to leak fuel around creases that formed in the join between the top and the bottom sections.

Someone on a Stirling engine forum pointed me towards a different method of making one. This method involves no holes, but it just encourages those creases that mine developed by itself, and I think it might be a winner.

Their's also used a drink can, but I think it might make a more robust version if I used a tinned food can.

So, to start with, I peeled a normal, every day food tin.











The first step was to trim it to size.

I needed the top to fit into the bottom, so the first thing to do was punch a hole in it to enable a cutting tool to get in there.

I used that mystery tool that pocket knives have.

Probably a leather working tool or something.

Who knows, just punch a hole in the can.


Next jam in some tin snips or something to make a nice cut to separate top from bottom.

My tin snips are stupid, so I ended up using scissors.

This isn't the best way to use scissors, so don't do this at home unless you actually own the scissors.





One very good method of cutting a tin can, is to just tear it by grabbing a ragged tail of tin with a pair of pliers and twist. If there's a groove to follow, it actually makes a pretty straight cut.









As I said, I ended up using scissors to trip everything to it was nice and neat.

I made the inside sleeve (the one on the left), slightly taller than the other so the pot could sit on the rim and let the gas escape from the gap between the outside sleeve.






I bent a series of grooves in the base of the inner sleeve so that they would allow the flow of gas, and also allow the inside sleeve to fit inside the outside sleeve.

This was simply a case of grasping with pliers, and twisting them to the left, and slightly down toward the centre.





Next I inverted the inside sleeve and carefully positioned the outside sleeve over it so that I might press the two together by stamping down with my foot.









Which failed completely.

2 comments:

  1. I absolutely LOVE the end of this post! This is what makes your site one of my favorites.

    ReplyDelete

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