Instructables

Step 10: Making the Penny Stove (Final Steps)

The assembly of the stove is by far the most delicate step in the instructable. Be very careful here.

1.) Slide the top into the bottom piece. (Image 1)

2.) Very, very carefully, start pressing the two pieces together evenly, a little bit at a time. When it starts to get tight, you will find that at the top of some of the holes that were punched you will need to use a shim cut from the spare parts of the can (Image 2) to work the two pieces down. Again, do this very, very slowly, a very small amount at a time. Do not use a lot of pressure. If the two parts seem to be too hard to push together, simply wait for a few more seconds. The two cans will slowly stretch ever so slightly allowing you to eventually work them together. I cannot stress enough how delicate you have to be, making sure that all sides evenly go in tiny fractions of an inch at a time. Attempting to force them too quickly will make either one of the cans split, or one end will pop out of the bottom while the other end goes in too deep. Slow and steady here.

3.) Gently, slowly, and evenly press the cans together until the bottom is even with the curve in the top. (Image 3)

Notes:

  • I say again, you do not want to sand the paint off of the top piece. As the paint heats up, it will actually act like "glue" and seal the top to the bottom piece the first time you use it.
  • As said above, you also do not need to use glue to make this.
  • Since this stove will not recieve ANY weight, it does not have to be reinforced, or otherwise made any stronger. (After its initial lighting, the paint on the inner can adhering to the outer can will still make it fairly sturdy.)
  • Note that I did not use any fillers such as cloth, fiberglass, etc.
     
Throw your favorite lucky penny (NOT quarters, dimes, or other ridged coins) in, and you're ready to go. This is as much as needs to be done to make the standard "Penny Stove."
 
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SgtHawk2 years ago
I'm a newbe and find this site and your particular instructions to be nothing short of outstanding. I do seem to recall from one of the hundreds of instuctions and youtube videos I have watched that freezing one can portion and heating the other allows them to go together easier.
Again thanks very much for one of absolute best of the best!!
Where exactly do we put the penny?
do i put it in before i connect the two pieces?
sorry if it's a dumb question
It goes on top of the whole. Watch his video to see it in action. http://www.youtube.com/watch?v=Bj5xZmXOZ8A&feature=related
mwarren_us3 years ago
Heating the bottom (to expand it) and cooling the top (to shrink it) makes this step much easier. Heating the bottom to at least 400°F (in a toaster oven) and cooling the top to 0°F (standard freezer temp) creates a 0.002 inch clearance making it much easier to slide the top into the bottom. You may need to use oven mitts!

While 0.002 in. might seem small, it's enough to greatly simplifiy the assembly. Here are my calculations... http://www.editgrid.com/user/mwarren/Aluminum_can_walls
Speaking of the penny.... I'm working on mine today - it's the first penny stove i've made - I tested the core, and I'm getting flames up around the penny. What did I do wrong? I didn't let it burn long. When I saw the flames around the penny I got worried. Was I just too sloppy filling it?
Javin007 (author)  johnnypanic133 years ago
I'd really have to see pictures to be able to give you an idea. (Sorry for the late answer, I didn't get an E-Mail saying you'd responded.) If the directions are followed, (and I'm not saying you didn't follow them, but maybe that different materials were available to you) then this shouldn't happen. Very, VERY small blue flames from around the penny are possible, but shouldn't really happen. Fortunately, the point of the penny seems to be serving its purpose in that it keeps the stove from detonating. :)
I'm not sure what it was exactly, but the more attempts I made the less and less this occurred. My latest versions don't seem to have this problem at all. I'm still not sure why, too many variables in the mix. I tried different hole sizes in the middle, and different numbers of holes around the edges. I think that when I made that central hold a little smaller I quit getting flames around the edge of the penny (I keep a drill bit set aside just for my penny stoves now).

One other thing I've started doing that might account for it: after pouring fuel into that central hold, and covering it with the penny I wait a little longer before igniting it. That way anything I spilled evaporates off. That might have been the cause too.

I haven't had a detonation yet (fingers-crossed) but I had one tip over. The penny fell off and that central flame ignited. It was on a concrete patio so no harm was done, and it looked pretty cool. One nice long (about 2 foot) flame jet out of the middle that burnt out in 5-10 seconds.

I'll put some pictures up. I gave away my best ones at Christmas, but I'm determined pull together everything I've learned and make one more nice one just for me.

Thanks again, these have provided hours and hours of entertainment.
Christopher
Javin007 (author)  johnnypanic133 years ago
:D It's always awesome to see someone building and enjoying the stove. I quite literally came up with the design one evening when I couldn't sleep. It was one of those, "I wonder if this will work..." things. Since then, I've seen videos of people using it in Brazil, Australia, Germany, and New Zealand. It's just so cool to see other people enjoying it! It makes me wish I was more inventive so I could come up with something else! :D
lounice983 years ago
very very very very slow, lol i split the first one, but second one worked like a charm, used your technique and after every tiny fraction i let it sit a few minutes to stretch out a bit
IMG_0173[1].JPG
tjesker3 years ago
I built the stove and it works great except the top part of the stove sometimes pops off when I light it. The paint on the cans did not act as glue and stick the two halves together as mentioned in the directions. Any suggestions on how I can get the two sides to stick together? I get the impression I should not use the epoxy.
Javin007 (author)  tjesker3 years ago
Wow... I can say I've built literally several dozens of these and never had that problem. Maybe you could take some pics as you're building it? Also, where are you located? Honestly, there could be a different type of paint used in different countries. My suspicion is that there's something odd about where you're punching the holes and cutting the cans maybe? That really shouldn't happen.
Maybe I missed a step. One thing that confused me was in one paragraph it mentions using a hole punch to punch 8 holes and the next paragraph it mentions punching 8 holes with a thumb tack but it sounded to me like maybe the thumb tacks were just to make starter holes?. Anyway, I didn't punch any holes with thumb tacks. Was I supposed to?

I just went to the store and bought two cans of A&W root beer like in the instructions - maybe they will work better. Apparently not all cans are the same as I first tried two energy drinks from Aldi and could not cut them cleanly and then switched to two off brand tropical juice cans from Wal Mart and they cut easily with a razor blade but the the paint didn't glue the cans together. I am in North Carolina BTW to answer your question.
Javin007 (author)  tjesker3 years ago
Woah woah woah....

You need to read the instructions here very carefully.  The holes punched in the cans with the thumb tacks and the holes punched in using the hole punch are very, very different things.  Please read every step of the instructable and make sure you understand it completely before attempting ANY build.  You're clearly reading something wrong that I couldn't possibly make any clearer.

OK I was only looking at the thumbnail of image three on that page. Looking at the big picture I now see the small holes on the bottom part of the stove (I think it's the bottom?) But if I put holes in the bottom won't the fuel leak out?
Do you really throw a penny into the stove?
If so, where do you put it in there?
[This is the first instructable about a Penny Stove that I've read, sooo...I'm not really sure what's goin' on with that part. Sorry. C: ]