by hpmer » Mon Jan 06, 2014 12:11 am
Cool.
I built one this weekend as well. I find that the ratio of bottom air to top air works best at 4:1 or even 5:1. On my prototype I used 16, 1/4" holes up top on the inner can, and 20, 1/2" holes at the bottom of both cans.
What a mess. Either my skills at drilling holes in metal needs more practice, or my tools are inferior. I'm going with the latter.
So once I worked out the ratios, I built another with the same 1/4" holes at top of the inner can, but this time went with slots cut out with tin snips for the bottom holes. Much cleaner presentation, and works just as well.
These things are kind of fun to play with, in a pyromaniac sort of way. Next I'm going to try 3/8" holes up top to see what kind of difference, if any, it makes.
BTW, I used a 1 quart empty paint container for the outer, and a Progressive Soup can for the inner. Cut out the bottom of the paint can and the soup can is 'press fit' up into the underneath ridges of the lid. Pretty easy build.