So I'm putting together a pressure pot for resin casting. The idea is you use air pressure to 'crush' bubbles out of resin and silicon to make more details molds and casts. As I had previously mentioned, resin is a thick material even when it is in it's liquid form it's still quit thick and thus the resin itself can support some weight. When it comes to casting parts, this gives rise to the 'bubble trouble', ie bubbles in the resin ruining the details in the cast part. So by crushing the bubbles out of the resin, and the mold rubber when making a mold, I can in theory correct that problem.
So I did my research, found a good pressure chamber that rated for about 90 PSI, for about $125. Had to buy a coupler for for about $3. Bought a compressor for $190. Needed to add a sealed cap to the chamber. That cost about $2. a $5 roll of Teflon tape to seal up the connections and it looked like I was ready to go. I hooked up the compressor, sealed the chamber and made a test run. I watch the regulator gauge slowly rise. 5 PSI. 7 PSI. 9 PSI. 11 PSI... Suddenly the safety valve pops. I look at the valve and think it might have been caught on the compressor hose. So I empty the chamber, open it, reapply some petro-jelly, seal the chamber, and start the compressor. 2psi. 4psi. 6 psi. 8 psi. 10 psi. 12psi... POP goes the safty valve. Yep, the saftey valve is bad. on a bot that is designed and intended to withstand up to 90 pounds of pressure per square inch... the valve pops at about 12 psi.