Gas downdraft stoves are an interesting backpacking tool. So I thought I’d make one and try it out. It has passed the “driveway tests” with flying colors. The design is derived from plans available from section hiker so I will mostly describe the differences.
The major difference is that I used one large piece of hardware cloth and four #6 bolts with standard washers, lock washers and nuts. Two of the bolts hold the hardware cloth wrapping together and the other pair of bolts stabilizes the alignment between the can and the hardware cloth (keeping it all square). I found that the fancy t-washers were largely a waste of money and didn’t help with either assembly or stability.
This made the manufacturing process easier and makes the stove cooler to handle as the hardware cloth is removed from the side of the can. The total weight after burn in is 101 grams, so this is not a large weight penalty.
To use the stove, fill with short pieces of wood laid sideways (some designs place them up and down, which didn’t work quite as well). The wood should not be much larger than a pencil. I was able to use pine straw and small tinder to start it (pile on top and let it burn down). Once it is going the nearly colorless flames extend quite high.
It is hot, burns for about 10-15 minutes and I think will work. I’m more optimistic about this than ethanol stoves. (it is also approved in the “guide to safe scouting” as it isn’t a home made liquid fuel stove)