I know this is an old thread, but I thought I’d share my experience with a DYI dry ice
fog machine.
We are in the middle of a production of Frozen Jr., and was asked to produce
fog. We built 2-55 gallon
barrel machines, from info we gathered here and elsewhere on the web. Our first
barrel was a 55 gallon metal with 2-4” outlets, fan, and 240v water heater
element. When we tried that, it wasn’t enough, so we built another 55 gallon plastic
barrel, with 2-6” outlets, and a 120v water heater
element (no fan). With these two machines, we can
cover a 30’ x 100’
stage for the 3 minute song, with 25 lbs of dry ice.
We also found out that the fan is really not needed, or helps as all, and if there is too much airflow it just causes the
fog to dissipate. The
fog will come out fine on its own, as long as you have a reasonable seal on the
barrel and the
outlet of the pipes are lower than the water
level. We really can’t tell a difference in the 4” hoses vs 6” hoses.
Our first one was the metal
barrel. Everywhere I read said you must use a metal
barrel. We had a plastic
barrel lying around so we just used it for the second one. I’ll have to say, plastic is the way to go. Much easier to work with and won’t rust. The metal one, after just a couple of practice runs, is already rusting quite a
bit. I don’t suspect it will hold up very well long term. The plastic also seems to hold the heat in better.
As far as warmup times, it takes the 240v
element about 1 hr to get the water to 140 deg (seems like a decent temperature), and the 120v about 1.5 hr to get to the same temp. We have both barrels filled to the first rung, I’d say around 15 gallons.