Super Cat Stove

[Steve .]

Although I haven't used it in the field yet it works great in the house. Brings 2 cups of cold tap water to a rolling boil in about 6 minutes (prime: 1 minute; cook 5 minutes) using less than 1oz of SLX Denatured Alcohol. Room temperature: 64F.

I ended up using a Zen Stove template as a pattern for the holes.

Instead of following the pattern exactly, I punched 11 holes for the bottom row – added one extra hole because the template did not cover the entire can. Then I punched 11 holes for the top row.

The holes for the bottom row are 13/16" from the top of the can; holes for the top row are 3/8" from the top of the can (like the template) but positioned half way between the holes on the bottom row. This gives it a nice symmetrical layout.

I also modified a single hole paper punch to make the holes. This gives clean holes without ragged edges that cause turbulence.

Cost: $.27 for the cat food can and $.97 for the hole punch at Wal-Mart.

Circa 1960 aluminum pot holds 5 cups and has a tight fitting lid.

Stove weight: .7 oz
Pot weight: 4.8 oz with lid, handles have been removed.
Pot diameter: 5"

[James Pitts]

…a tried and true design. These "simple" stoves often work best for people. I remember being sceptical that a tea-light tin would work well… it's just a tin with no modifications at all… but it does work very well. The best part about making the cat stove is feeding the cat food (to the dog in my case). :)

[Steve .]

I looked at a tea-light but thought the fuel capacity would be a limiting factor.

Do you use the tea-light with a regular pot or beer/soda can?

Thought I would try the Super Cat with a pot stand to see if a little extra space above the stove would speed things up or require less fuel.

[James Pitts]

I use it with a Fosters can pot, the "Ultralight Outfitters" beer can rig, when I don't use Esbit.

[Adam Kilpatrick]

Ive made a couple of these without the template-just guessed on number size and positioning of holes. Works fine.

I think the best thing about the super cat is that it is so simple-stand and stove in one very robust piece. If it gets bent in your pack just bend it back. Lose it, knock up another in about 10 minutes. Someone you meet on the trail likes the look of it-give it to them-didn't cost you anything and just made their day. Makes life less complicated, even though there may be faster/lighter/more efficient options out there. There is something to be said about that, which is sometimes missed in the pursuit of super-light and fast.

I am glad you enjoy that stove design aswell Steve!

[Jason Klass]

Steve,
The Supercat needs to have the pot on top in order to pressurize it. Using a stand will alter the flame patterns. If there is nothing to seal off the top, the flames will not be forced out of the holes on the side and will just come out the center. Just a heads up.

[Steve .]

Jason, when I lift the pot just a bit (1/8") off the top of the Super Cat it looks like a more intense flame; blue flame in the middle and blue flames still going out the holes.

My thought was that since a larger surface area was being heated water would boil quicker. It also might help at altitude where there is less oxygen.

[Eric Carlsen]

How did you get the hole punch to work? I bought one at Walmart (also the $0.97 model) and tried to adjust it so that it could open wider. I accomplished that, with a lot of work, but then I found the hold punch couldn't punch through the can (I used a canned meat can, maybe it's thicker?). I ended up bending the hole punch. I think part of the problem was that the hole wasn't aligned very well after I modified the punch, but I'm not sure that was the entire problem. Anyway, any tips would be appreciated.

[James Pitts]

… well if you lift the pot off the top of the stove indeed it will change the pressure inside the stove, but combustion requires a fuel + oxygen mixture and in the center of the stove there probably isn't any oxygen. If I were to guess I would think that fuel would go up, out the sides, and combust with the outside air where you see the flames from the burner. It would probably be hotter because you are burning more fuel. It would be another matter as to if this would make the water boil faster since the system might not be able to absorb the extra heat. Good testing should answer these questions and would be easy enough to do.

[Steve .]

Eric,

I used pliers to remove the tab that prevents the hole punch from opening up wide. The photo below shows the area where the tab was originally located.

My hole punch didn't operate very smoothly before or after I removed the tab so I filed down the punch part of the tool a bit. After that it would open and close smoothly.

I also removed the little black thingy where the paper snibbles usually end up.

When punching the holes I put the punch part inside the can then used the hole part to line up with the template on the outside.

It does take a bit of force to punch through the can. I padded my hand with a thick glove to make it easier on myself.

Hope that helps.

[Eric Carlsen]

Great picture, that should help a bunch. Thanks.

[george carr]

I made one of these just two days ago and found that at least under optimal conditions (my kitchen, 70 degrees, etc.) this stove out performed my pepsi stove hands down. I had 8 ounces of cold water at a rolling boil in under 3 minutes. This stove does seem to work better with a wider pot. I look forward to field testing this design soon.

[David Wills]

I made one a few days ago too. It took a little manipulation to stop the pulsing I got from holes that werent big enough, but once it got optimized, I got 12 oz of cold water rolling in 3:30 in my kitchen. It began to sound like a jet plane toward the end of the cook cycle. It outperformed my etowah outfitters stove. I am definatley switching to this stove for 90% of my trips. Awesome design.

[Cameron Reed]

Did you put any fiberglass insulation in the bottom? Or is t just an empty can with holes punched in the sides? Just curious.

[Steve .]

Empty can.

[Robert Blake]

From my hammock camping forum–one Ralph mentioned a hole punch available at harborfreight.com. I could not find the one he mentioned-but, their hand punch is made to put holes in thin steel, aluminum and brass. It seems to have a wide gap. And, it has punches for circular holes of the following diameters: 2, 3, 4, 4.5, 5.5, 6, and 7 millimeters. It costs $20 (plus shipping charges) but would allow for versatile experiments with different hole sizes.

R Blake, Flagstaff, AZ

[Mark Hurd]

If I'm not mistaken a cat food can is made of thin aluminum and a cheap paper punch can do the trick. If you want to punch steel cans or Ti sheet, etc go for the HarborFreight or like models.

-Mark

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