We just purchased a vacuum forming machine and we've tried a couple of different mold with it and still cant get a decent part that demolds easily. I machined a couple of molds from MDF but it clogs the vacuum when I place the mold over the vacuum hole. Is there a certain type of MDF, or another material, that is porous enough that the air leaks through it? So far we have only tried 1/8" ABS but we'd like to find some less expensive materials to use as well. I'm curious to know what other materials you are using and what temperatures you use for them. Thanks!
-David