View Full Version : Why the penny?
pgustaf249
08-13-2010, 15:03
I'm new to the hiking crowd. I'm learning about trekking poles, tents, hammocks, cooking, etc. and have a question about the alcohol stoves I see people building on Youtube. I notice that some folks place a penny in the center of their alcohol stove built from a couple of aluminum cans. What is the significance of placing the penny in the center?
I think its to extinguish the flame.
Nevermind, I that is not why they use the penny.
ky chris
08-13-2010, 15:30
the penny seals the filling hole causing the stove to pressurize and form jets of flame around the sides.
The jets of flame will boil water faster but not necessarily more efficiently. They also look cool.
...... and remember- Always place the penny heads-up for good luck.
...... and remember- Always place the penny heads-up for good luck.
wow. that explains why sometimes i can't light the darn thing. got to remember that.
RedneckRye
08-14-2010, 01:38
Wouldn't a dime be lighter?
Hate those heavy coins..use an aluminum screw in mine.
mateozzz
08-14-2010, 13:56
I think the penny is about the correct weight to be heavy enough to seal and prevent the alcohol from running under until enough suction is created in the space underneath. <science>The burning alcohol on top causes the air underneath to heat up, expand, and escape out the holes. This causes a drop in pressure under the penny and when it gets low enough, the alcohol gets sucked under the penny and (hopefully) starts boiling. The alcohol vapors then flow out the holes and make nice jets.</science> Its a good weekend project, I've build a couple of variations but the penny works pretty good. Its also a good conversation starter at shelters!
crazyonelost
08-14-2010, 15:47
I had a penny stove go up on me. So I have avoid any alcohol stoves at this time. Until I figured out what went wrong. I seen other hikers use them and they never had the trouble.
Wouldn't a dime be lighter?
I think pennies are lighter.
Danielsen
08-14-2010, 17:34
Dimes are lighter for sure, but that's not necessarily a good thing for the proper function of the penny stove. And I mean... a couple micrograms, probably. Seriously worried about that? :p
SKessler
08-17-2010, 23:39
I started using a dime because it was the only coin I had on a trip. It is now the only coin I use. Slightly lighter and works just as well as the penny I tested with did. Now I just use the really old gnarly looking dime. "it's just money."
Anumber1
08-18-2010, 00:51
The penny is heavier but costs 10 times less than the dime, so if you're on a budget just use the penny.
The penny is heavier but costs 10 times less than the dime, so if you're on a budget just use the penny.
Coffee just shot out of my nose!!!!! Too funny ;-))
Uncle Cranky
08-18-2010, 08:56
I usually make a wish just before lighting up.
cutman11
08-18-2010, 11:25
I have the penny stove, and can heat 350 ml of water to boiling with 3/4ths of an ounce of alcohol in 2.5 minutes, reliably if temp is more than 35degrees. It is the most efficient alcohol stove I have seen. There is a website showing how to make it. Weighs very little. It is safer than a truly pressurized stove (bolt sealing the fill hole) which could explode, and more efficient than non pressurized stoves.
Different Socks
09-08-2010, 12:26
Sorry guys and gals, but I hate to disagree with you. I was given an alky stove last year as a B-day present and also I was fascinated by the demo my friend gave me. Unfortunately, I noticed 2 things: 1)I could never get the right amt of fuel in the stove even when I used a small measuring cup(about the size of the cup on a Nyquil bottle) that I got from the lab at the hospital. 2) The stove never seemed to burn regularly, and you can forget about a steady flame when there is the slightest breeze(yes I used a wind screen).
I attempted to use the alky stove several times on day and overnight hikes and was not satisfied with the performance. So I'm sticking with my MSR Whisperlite.
JMHO