Hi there,
I live in Singapore and am keen to cast my own figures. I have a vacuum chamber setup that i inherited from a friend who's moved back to the UK, and am trying to cast my own sculptures using it.
However, when I activate it, I can't seem to get the chamber itself to evacuate right down to 30 inHg, which is what I need to get the cavities out of the resin I use (smoothon smoothcast 300). In fact, I can really only get it to get to about 26 inHg. We tried it with 2 different pumps, my quite small one and one massive industrial size, and only about a 40L chamber, so I can't see why the chamber won't reach the required level of vacuum.
Is it something to do with humidity? Can the pump not pull 30 inches in the kind of humidity we have here in singapore? Or maybe is there a defect in my chamber that's stopping it happening?
cheers
zerobmeister