The Krylon Fusion looks like a good idea for next time, but I've already done the spray painting. As far as the potential cracking, I've only spray painted the barrel and not the chamber. The barrel shouldn't expand and contract right? so poly would be ok then? maybe? Also, should I use I brush on t...

I just recently spray painted a design on one of my pvc-made potato guns. I wanted to protect the spray paint and design because it easily scratches off when bumped or dropped on the driveway. I was wondering if i could polyurethane of the spray paint to protect the design? Any other ways to protect...

i have looked through. I've seen things like .8:1 or something like 1.25:1 but some people agree and others don't. I've tried interpreting those numbers as lengths, and as cubic inches, but when I try and plug it into the HHGT (again I forget the abbrev.) and change the numbers that I do understand,...

ok so im fairly new at this, just built my first combustion cannon last week, now i want to build a pneumatic one. All im looking for is best lengths for a 3" chamber and a 2" barrel, using a 1" inline sprinkler valve. I've searched through the forums and I've tried the different HHGT's (or whatever...