Tuesday, December 16, 2014

The YACC Stove Original Directions

Ray Garlington who is the author of this post has given permission to grab it and his photos from the wayback machine and post it here.  I think this is the easiest pop can stove one can make and this post is what really got me started with making my own stoves.  I like this stove because it is easy to make and it saves extra weight because it serves as a pot stand.  This is also a very efficient stove.

When I first starting trying to make a pop can stove all the directions I found were too complicated and I almost gave up and then I found this page that changed everything for me.  I still make my own stoves and I only make simple ones like this.

Thanks Ray!


The Garlington YACC Stove
4/6/2004



Yet Another Coke Can (YACC) Stove

Got 5 minutes, a coke can, and a pair of scissors? If so give this little stove a try. It is easy to make, and uses only one can. Also, the pot sits right on top, so it doesn't need a  pot stand. Just add a piece of aluminum foil for the wind screen & you are good to go. The YACC stove can raise a pint of 65*F water to 135*F using 1/4 oz of alcohol when air temperature is around 65*F. I have found this sufficient for my lightweight 'cooking' needs. A 4oz supply of alcohol lasts me for 16 stove firings, which equates to 4 gallons of 'hot' water. Of course, if you need more heat, you can add more fuel.

The stove was inspired by the Antigravity Gear stove (uses two cans) and "The One Can K.I.S.S. Soda Can Stove" by DeoreDX on the TLB Forum. I liked the idea of using just one can, and wanted construction to be as easy as possible. The YACC stove can be made quickly with just a pair of scissors.



Here's how to make it

Obtain an aluminum soda can.

Remove the opening tab from the top, and tear the top out with a pair of pliers.


Mark the side of the can 3/4" up from the bottom. Flip the can over and mark the side of the can 1 1/2" from the top.

Using a pair of scissors, cut the can in half
Now, carefully cut along the marked lines. If your marked lines are on the 'thick' side, cut the bottom along the outside of the line (thus making the bottom slightly larger).
Take the top section and cut slits every 1/2" from the cut edge to just below the shoulder of the can top.
Push the tabs slightly toward the center and slide the top section into the bottom section. Push the top (carefully) all the way down into the bottom. The tabs of the top will follow the can bottom until they jam up against the domed part of the bottom. As the shoulder of the top starts to go under the cut edge of the bottom, look for bulges that might tear the bottom and push them inward with the flat side of the scissor's blade. When fully seated, the top's shoulder should be slightly under the bottom lip. None of your slits should be visible from the top. (If they are, you will need to cut another top.) Hold the can together and roll the cut edge of the bottom slightly inward over the top's shoulder to hold the stove together.
If the details above sound too tedious, just push your two stove halves together. At first, your stove will spring up so that the top slits are exposed. Don't worry, because after you light the stove, you put the pot on, which will compress the stove anyhow. After using the stove a few times it will stay compressed (particularly if there was a little soda left in the bottom).

Theory of Operation

OK. Now that you see how it goes together, how does it work without any gas jets? Well actually, the jets are there, but hidden under the cut-edge of the stove bottom. All those cuts in the top allow gas to pass through which find their way out the small gap between the can top and bottom. So, in the end you have a two wall (well sort of) stove that is pressurized (again, sort of).

Operating Instructions

This stove requires preheating to the point where flame comes out the seam. Details:
  1. Pour the fuel into the stove body. Denatured alcohol, Heet, everclear, and similar products are good fuels. 1/4 oz of fuel will burn for about 3 minutes.  Note: It has been reported that the stove will not burn on rubbing alcohol.
  2. Position the wind screen and light the stove by holding a flame above the large hole.  Watch out because the stove lights easily and the flames are nearly invisible at first.
  3. Hold your pot about an inch above the stove until flames exit the side of the stove (about 15 seconds). When that happens, immediately position the pot on the stove.

Adjustments

Variations in building technique may cause you to end up with a stove that has problems.

Stove burns too fast

If you think your stove is burning too fast, you can extend the burn time by making the stove a little tighter. Separate the stove halves and flatten all the slits as much as possible. When you reassemble the stove, make sure that none of the slits are visible (i.e. make sure they are hidden in the bottom of the stove). If the slits are showing, even though the top is pushed as far into the bottom as possible, remove the top and cut off a little from each of the tabs. When you reassemble the stove, the top will go further into the bottom, hiding the slits. A tighter stove makes it harder for the vaporized alcohol to get out, so that burn speed will be reduced. The slowest I have been able to make the stove burn is for 11 minutes on 1/2oz of fuel.
Stove burns too slow
It your stove burns to slow, or fails to ignite on denatured alcohol, you need to loosen the gap between the top and bottom halves. Push a needle into the seam between the two halves in about 5 spots spread evenly around the can.

Burping Stove

The most troublesome problem reported seems to happen when a relatively large fuel load is added and the stove gets too hot.  If this happens, liquid alcohol is forced out of the stove onto the supporting surface where it will ignite.

Burping stove repair #1 (Posted by Parkinson1963 of the Lightweight Backpacker

"I figured out the burp is cause by a build up of pressure in the stove between the the two walls. The solution is to bend about four of the fingers into the open part of the can slightly, making these slits slightly wider. This allows the presure between the walls to be less, and less likely to burp. After six consective burns with one ounce of fuel each time, no burps.
This is the best stove so far two cups to full boil on 3/4 ounce of fuel, no pot stand only need aluminum foil to make a windscreen. Fantastic!!!"

Burping stove repair #2 (Posted by Parkinson1963 of the Lightweight Backpacker): 

"I discovered another easier way to eliminate the burping problem. Simply make four holes just below the top rim I used the awl on my swiss army knife. A tight very carefully made stove plus the four holes made for a perfect stove with no burping."

Burping stove repair #3 (Ray):

Using a sharp push pin, punch a row of holes around the shoulder of the can. Punch them above the seam between the stove bottom & the top. They vent directly into the center of the stove and keep the internal pressure low. They have the appearance of the gas jets on the usual pepsi stove, but when the stove is operating, it looks like the flames are emanating from the seam.

Enhancements

Here are some other construction ideas you might like to try:  add an interior wall to the stove, cutting the top out cleanly.

Add an interior wall to the stove

If you do this you have, in essense, the anti-gravity design built with one can, but without the careful sealing. It takes a few extra minutes, a stapler and a needle to do this. Here is what you need to do:
  • When you cut the can in half, be a little more careful and cut closer to your 'top' line. Your objective is to leave enough aluminum from the center of the can to cut a strip 1.25" wide for the complete circumference.
  • after cutting the top and bottom pieces, carefully cut a 1.25" wide strip from the center section of the can. Take the time to draw lines and cut carefully.
  • take this strip of aluminum, fashion it into a cylinder and slide it up into the groove inside the top of the can.
  • hold this strip together with your fingers, pull it out of the top, and staple it together about 1/4" down from the top.
  • Take the strip, and use your scissors to cut 1/4" long slits, about every 1/4" around the bottom of the strip (the rim of the cylinder furthest from the staple).
  • Slide the strip into place in the top and assemble the stove. Push the top and bottom of the stove together as tightly as possible, then run the back of your scissors around the seam to make sure it is lying flat and there are no tears in the bottom.
  • Take a sharp pin and punch pinhole jets into the top about every 1/2" around the circumference of the stove, just above the seam.
  • With this modification, the stove burns longer with a more even flame. I get 4+ minutes from 1/4oz of alcohol and higher final water temps.

Cutting the top out cleanly (Posted by Rambler of the Lightweight Backpacker):

For me a can opener does not work well cutting out the top as it did when cutting out the bottom of the original pepsi can stoves. A 2" hole saw fits the can top ridge circle pefectly. Holding the saw cutter by hand rather than attached to a drill and then turning the can and drill in opposite directions by hand soon cuts out the top cleanly. However, it is best to use this method before cutting the can in half, ie. after removing the tab, the next step is to remove the top. A key instruction to a successful stove is to be careful to make the slits 1mm above the shoulder. Using the guiding line is a useful tip. Thanks to rgarling for an easy way to build an effective stove.
Comments from Tony Wong about his first YACC stove:  (sorry about the lost pictures....)

 I was quite pleased with my first attempt. I used a Pepsi can and followed your instructions. Here's a shot of the stove in action burning methyl hydrate (paint thinner grade).

// picture missing//


Some of the things I ran into/discovered.

  It took me some time to figure out how much a "quarter of an ounce" is as it's been a while since I measured volume in imperial units. I managed to find a graduated cylinder in both units and discovered a 1/4 oz is equivalent to about 7 millilitres. 

  In your instructions, I wasn't sure where to light the stove, in the big hole in the top or try and light vapours coming out the side. In the end I just lit the fuel inside the big hole in the top, eventually the stove started to work, so I guess that's the trick. Perhaps a worthwhile addendum to your web site instructions?

  Performance wise, 1/4 oz (7 ml) methyl hydrate heated one cup (250ml) tap water to point too hot to put fingers in. Sorry don't have a thermometer handy. I seem on the short side of max temperatures and burn times reported by others.

  I found a carpenters marking gauge made it easy to measure out and scribe lines around the can. The gauge has an adjustable fence, measurements on a ruler, and a scribing awl.

// Marking gauge picture missing //


  To cleanly cut out the top of the can, I tried a round hole saw, but found I wasn't making any headway in cutting the top off. Instead the teeth were scraping along the vertical surface where the top of the can meets the thicker rim of the can. But I discovered when I used a bent needle nose plier, that the hole saw had thinned the aluminum sufficiently where the can top meets the thicker rim and the metal tore away nice and cleanly. A bit of filing took the sharp edge off. Unexpected, but it worked out nicely.

  Initially, I couldn't get the two parts of the can to stay together. But after the first burn, it seems the paint and varnish on the top part of the stove gets burned off and the surface is less slippery. The increased friction seemed to hold the 2 halves of the stove together nicely without any other physical fastener. I didn't have any luck rolling or squeezing the circumference of the stove bottom to hold the top piece in place. I tried a circumference clamp all around the can, but I couldn't reduce the diameter of the outside can to hold the inside can. But after the first burn, it was no longer an issue.

 To get the slit length correct, I used a scrap strip of aluminum and inserted it into the can bottom and pushed it down until it bottomed out against the bulge in the can bottom, just like a slit in the top would do when the stove was assembled. I marked the strip at the top edge of the can bottom and used that to mark how long the slits needed to be. After assembly, some of my slits extended above the top of the bottom can--I must have cut the bottom can a bit too short. On the next stove, I'll cut the slits first, insert into the bottom can, and mark where I need to cut the bottom can off to ensure the slits are covered.

Thanks,
-Tony
Vancouver, BC Canada

Let me know how your stove works out. Reach me at rgarling AT yahoo DOT com
Thanks
Ray

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