Penny Stove

Stuck inside on a cold and rainy day, our 6 week old sound asleep, my nine year old chicken pox inflicted Cub Scout and I decided that today was the day to make a penny stove.

We used 2 empty cans of Molson Canadian, 1 full one, on exacto knife and a bit kit to give us an even edge.

So far, we haven't used any jb weld and we haven't tired it out yet. But, my husband is on his way home with a yellow bottle of Heet so we can give it a go!

Better make them now, no more pennies in Canada.



Coke can works too, I made two with them since I don't have any beer can either.

LOL@jzmtl!

I never gave much thought to what brand of can we used but now my son is on the hunt for something in a gold can so he can make a gold stove. I suppose, though, that different companies might use different grades of aluminum in their cans. A thicker one would last longer, I suppose, and probably have different heat exchange qualities?

We're going to keep working on this and try to improve it. We didn't sand any edges or seal the seam on this this one. There are also different designs that we'd like to try.

I've never used one of these before so am a little unsure about how best to light it. I've seen people use a warming plate/cup and others just light it at the filling holes. Any suggestions?

I believe the warming plate or priming cup helps ignition in low temperatures. In balmy climes just get the match near the holes and away she goes....

Thanks hikermor! It's good to know what the differences are. This is more than just a 'make camping stuff on the cheap" process for us. It's also a science experiment so we're going to try it both ways.

I'm currently on the hunt for a good website for kids to help explain some of the science, so we'll have a better understanding of our own observations. If anyone knows of such a site, I'd be grateful for the guidance.

LOL! I actually bought this beer specifically for this project. Not sure which ends up being better for the environment in the long wrong, but I like the taste out of a glass bottle better than out of a can.

Jacqui... once your Scout sees the value of an alcohol stove, a Trangia is a nice birthday present..a lot more durable, doesn't need to be pre heated (at least down here) and the simmer ring allows you to control the heat...

two sites for alcohol stoves, Second site goes into design and science more than the first.
http://wings.interfree.it/html/
http://zenstoves.net/Stoves.html
regards

Oh, dear, playing with stoves. Tsk, tsk. Nothing good will come of it. Just look at me.

The principal of the penny stove is fairly simple. You fill in the center hole with methyl (HEET) or ethyl (drinking) alcohol or a combination of the two ("denatured" alcohol). You put the penny on the fill hole so nothing comes out.

Then you "prime" the stove by putting it in a shallow "priming pan" (I use the lid from a tea tin), pouring a little alcohol into the priming pan, and igniting the priming alcohol.

Now, here's the science: The priming alcohol heats up the alcohol inside the stove. The hotter the internal alcohol, the more vapor it emits. That vapor needs somewhere to go, but there's a penny blocking the fill hole. The only way out is through the small jets around the rim of the penny stove. The vapor is the only thing that will burn. Liquid alcohol will not burn as is. As the vapor rushing out the jets burns, there's a thermal feedback loop that occurs: heat from the jets warms the stove which warms the alcohol which emits yet more vapor which rushes out the jets where it is burned heating the stove... and so on. It's pretty cool.

So, where are the flame shots?

HJ

Thank so much, Jim! the science experiment continues today when we light it. Stay tuned for those flame shots.

K--

little confusion- with a penny stove- why would you need a separate priming pan?

after you fill it, just add a teaspoon ON TOP of the penny-

the alcohol on top both heats the alcohol underneath AND ignites the jets once vapor come out.

I know this works on the shorter ones I built....

Heat rises.

In colder wx, I've had trouble with top priming.

HJ

the Trangia has a brass inner wall in the central chamber that conducts heat to the vaporization chamber... I know that it's fun to make the penny stoves, but it's nice to be able to extinguish the flame to preserve fuel...

In cold weather the fuel on top would burn out before vapor starts coming.



Just use something to snuff the flame and pour out the remaining fuel.

Those Trangia's look very nice, Les. I've got one on my wish list.

In the meanwhile, we made a snuffer out if the bottom of a third can. It fits perfectly over the top of the penny stove, covering all the jet holes.

I hope you are looking at the various types of Trangia cooksets; the stove really works best in an integrated system. My favorite is the Mini-Trangia (T-28). It is perfect for one or two people. It also works well with canister stoves.

You know, I'm not much of a shopper, except when it comes to outdoor gear. I've been trying to ignore to cook sets but I guess if the burners work better with them... :-)

Thanks hikermor!

Just wanted to follow up to confirm that we did have a fire extinguisher on-hand when we did this experiment.

Here's a picture of the snuffer we made out of another can. SO simple!

BPJ,
Talking of home-made alcohol stoves. I found a few years ago I could quickly drill the outgas holes in the top of the stove by chucking an ordinary straight pin in an electric drill.
Re: cook kits. I have used an aluminum pot-pie pan to cook small muffins in the smaller of two cooking pans, suspending the pie pan above the inner surface of the cook pan with a small spiral of aluminum foil.
A hiker named "Risk" did a nice write-up of trail baking on his website. www.imrisk.com

My son and I have made more progress on our penny stove project and turned it into a cook set project! The plan is to make a compact kit on the cheap that we can use to boil water and heat up food. It's also includes a small backup fire kit.

We're still working on it but here's how it sits this afternoon:

COOK SET PACKED (packed in really big mug along with a spoon)


COOK POT PACKED


CONTENTS OF KIT


COOK POT CONTENTS:
-penny stove/snuffer/penny
-hobo stove/pot stand/wind screen *repurposed can of corn
-lighter
-SA matches/cotton balls/pine pitch *in repurposed film
-canister
-alcohol (HEET)
-cook pot with lid/frying pan *repurposed SS sugar canister
-bandana
-aluminum foil

TO DO:
-need small bottle for fuel
-add some iodine or microPUR tabs
-add more air holes and rack in hobo stove
-make wind screen for hobo stove
-make pot cozy for cook pot
-upgrade lighter to butane

We fired up our penny stove today. First, we tried unsuccessfully to light it at the fill hole. Then we used our cook pot lid/frying pan as a warming pan, and that did the trick.

Next step is to take it for a walk and try to boil water on it.

I can totally see how easily this stove will become part of my kit. I can't wait to get out and field test it.

I know that learning about how much fuel I need is going to be trial and error but I have a question about fuel. How do I transport it? Right now, I have a yellow bottle of Heet dedicated to this stove. Do I have to keep it in the original package or can I use something smaller?

Any tips or suggestions would be greatly appreciated!

Thanks Izzy. I've seen guys do that with their denatured alcohol, I just wasn't sure if Heet was more corrosive. Thanks!

LOL@8oz not being enough alcohol. I like the way you think!

Try this design, it's what I followed and works well. It's self priming so no extra pan needed in pretty much any above freezing conditions.

http://www.jureystudio.com/pennystove/

Thanks jzmtl! I'll check it out.

Thanks so much, Izzy! ...she says eyeing her little Nalgene shampoo bottles. MUCH appreciated!

Nalgene shampoo bottle filled with Heet and added to stuff sack, along with the kit. Thanks Izzy!

MicroPUR tabs added too!

I also swapped the film canister for a one of those $1 plastic match keepers with a tiny ferro rod on the bottom. It seems a little more durable that the film canister. It holds fewer cotton balls but I can keep the SA matches full length, which makes more sense to me since this is not my primary fire kit.