More info coming soon...
Why am I seeing pinholes in my hot coat? I make sure that all the dust is gone by pressured air and I work with a clean brush. What am I missing?
Most pinholes appear due to the amount of air that is going out from the blank due to change of temperatures from the exothermic reaction. If the EPS is fused cell, like Marko, the pinholes hardly appear on the surface. A good trick is to seal up the blank with epoxy and micro-balloons before glassing, that would make the difference. We also have a surfacing agent for sanding that works for the pinholes and fisheyes.
I want to start making skateboards. What resin system should I be using?
Do you plan on using heat with the mold? If so, you can use SuperSap 305.
Otherwise, if it's at room temperature, you should use the SuperSap CLR/CLS (slow hardener) combination due to the higher density of the system which would come up with less drain out of the press.