Pop Can Stove

[caliban]

At last! A working pop can stove. I know that this is old news, but I've made three of these before and all of them looked the part, and all of them ignited and jetted and generally looked the bizz, but none of them actually managed anything more than a low simmer. I made this one a wee bit bigger and put the jet holes in the raised ring of the can bottom instead of at the side of them (outside rim but still on the top). Don't know if this made any difference, but I'm getting a good proper boil for one full cup of cold water in about 10 miniutes, on a cold day. I'm well chuffed. Most enjoyable cup of instant I've had.

 

[Everything Mac]

looks good mate - i like the little guard you have made.

andy

 

[leon-1]

That design is a good one, look out online for the Don Johnson Photon Stove, they work very well if configured properly. They can and do get boiling times down to 3 - 4 minutes with them and their sister designs.

What did you use for the wind shield??

A foil barbecue tray???

 

[widu13]

I made mine double walled to increase the pressure. I can boil 500 ml of cold water in 4- 4 1/2 mins. It's not very big those so will only do one cup and I've over jetted it (too many jets) but all of mine are in the apex of the raised ring.

I've a tin foil platter tray as a wind shield as well!

ATB

 

[caliban]

3-4 mis is excellent, well done. Yeah it's a barbecue tray, put holes around the bottom with a leather punch, shield makes a difference too. What do you mean "double walled" Widu ? I'm thinking of wrapping a wick around it to catch some meths to make it easier to light, I saw one thta Tinny did like that.

 

[tommy the cat]

Try the cat stove too....easy to make 2 tablespoons of meths 8min burn 500ml in 5 mins (ideal conditions.)
dave

Sorry its a big pic though I had re sized it

 

[conall]

I've had loads of fun making stoves.......in fact everytime I go shopping the wife accuses me of planning my next stove project
this was the last beer can stove I made and the only one I kept as it's so flippin quick at boiling up water

 

[caliban]

Conall, that's a cool wee stove. I'm thinking that, besides being pressurized with the screw in fill hole, the reason you might be getting quick burn times is that your jets are directed inward localising the heat at a small diameter. Whenever I've made a coke can stove I've copied what most people seem to do and put the jets on the top outside perimeter of the can. This works great and when the can takes off it looks just like a trangia in terms of flame pattern. The difference is, I'm thinking, that a trangia is designed to heat up pans that are bowl shaped with a big top diameter. Can stoves are mostly used to heat billy cans which are straight up and down tubes. The flames on a can stove where the jets are in the outside position will mostly be hitting the outside edge of the billy can, where the metal is thickest and the flames lick up the side where they do heat the billy, but where they shed most of their heat outwards into the fresh air. I'm going to knock up another one with the jets inside like yours. I'm looking for about six minutes, now where's them two cans of cider?

That cat stove look great as well BTW.

 

[caliban]

Bingo....

Changed the configuration of the jet holes. Moving the jets to the inside of the depressed rim creates a column of flame that hits the center of the billy. Five and a half minutes for one mug of cold water to a good rolling boil, came to the boil in five minutes though. Easily boiled another mug and a bit that I chucked in (after I'd made a coffee) whilst I was waiting for the stove to die (16 mins). Sorry if this is a bit boring, but I've found it easy to make a burner that burns fuel, but it's been tricky to get one to actually boil water. I'm thinking that this might help someone in the same position. Tune the jets to type of vessel you're using, for a billy can that's about four to five inches in diameter that means jets closer to the fill hole.

 

[scrogger]

Do any flames vent under the coin Caliban?

 

[caliban]

In a word mate..no! I've had no problems with that at all. I let the centre hole burn until the wee holes ignite and then just flip the coin on, I think a ball bearing might be better than a coin though 'cos it would just roll into the right spot, not tried that yet though.

 

[gregorach]

I put the coin on before lighting, then fill the resulting well with fuel for priming. That way, you don't have to wait for the burner to ignite properly to get your billy on - although you do need to keep an eye on it to make sure it goes properly. It's worth experimenting a bit with different approaches.

 

[widu13]

3-4 mis is excellent, well done. Yeah it's a barbecue tray, put holes around the bottom with a leather punch, shield makes a difference too. What do you mean "double walled" Widu ? I'm thinking of wrapping a wick around it to catch some meths to make it easier to light, I saw one thta Tinny did like that.

Double walled- in the raised recesses fit a circular section of a red bull can or similar with 3 notches cut out to allow the fuel in-between the skins. This pressurises the fuel more giving a better jet.

 

[caliban]

Cheers Dunc, I've been finding lighting up a bit tricky, definately give that a try. Good idea.

 

[gregorach]

If it's reasonably warm, I find the easiest way to light these stoves is with a firesteel - lighting them with a ciggie lighter is asking for burned fingers. However, the firesteel doesn't work so well if it's too cold for the fuel to vaporise easily.

 

[scrogger]

Ok Geeky question time.

I once read a blogg on an American guy who did a comprehensive review of the MSR pocket rocket with burn times etc etc.

Caliban you mention 16 mins burning time how much fuel was that for that burn time as that would probably be enough to sort out a bit of scran and a brew?

 

[caliban]

Scrogger, I'm more of a see what works kind of person, so what I do is to just pour the fuel into the depression in the stove/can bottom until it reaches the rim, wait for it to drain in and repeat twice, so that makes three fills. I also sloshed a wee bit about to help ignition. I'd only do two fills and a slosh (ahh! the science...) if I was just making a brew now that I know. I punched a 3ml hole in the centre with a brad and the can is loosely stuffed with pink fluffy loft insulation so I suppose you'd have to take into account how fast you can expect the fuel to flow into the stove, and how much is going straight in when you fill the dimple. My stove is one and a half inches tall, I suppose that you could make it bigger to burn longer if you wanted. If you haven't made one of these before, the best way to cut it is with paper tape as a guide and scissors. Burst a hole in the middle hack the can in half with the scissors and then cut carefully along the tape line. Crimp the top end with pinch nosed pliers to help the two sides slot together (tricky bit). If you've got metal foil duct tape handy wrap it in that. It will work without it though. I'm not an expert by any means, these are just the things that I found out the hard way.

 

[gregorach]

In my experience, the best way to cut cans for this is to use a sharp knife (a stanley blade does fine) and a spacer block of the right height, on a firm level surface. Hold the blade firmly on top of the spacer, bring the can up next to it, and rotate the can - it'll take a couple of times round to actually cut all the way through. This gives you a nice clean cut with little risk of cutting your fingers on ragged edges.

 

[scrogger]

Cheers Caliban I have made a few but like you just keep faffing around with different approaches.

Duncan I cut mine the same way I have glued 2 blocks of wood together giving me a cutting height of about 45mm then I have fixed a Stanley blade to this with about a 1/2 inch protruding. I push the can against the blade until it is braced against the wood block and the twizzle the whole thing until its ut through. This gives a perfect cut every time at a uniform Height.

I am doing this with the Scouts next week so this thread has been a good read.

Thanks Chaps.

 

[tommy the cat]

Still think you guys should try the cat stove much easier to make and fuel imo.
http://jwbasecamp.com/Articles/SuperCat/index.html