What is everyone using as a tooling paste these days? I am trying to make some molds with my machine by under cutting extruded polystyrene coating it with an epoxy paste and then doing a final machine pass on it to get it ready for sanding and polishing. Most of the pastes I have found are either only available overseas at a very high shipping cost (easy composites), polyester based and will melt the foam (bondo), or seem to be only sold to large volume folks (pretty much every decent looking one I have seen in my Google searches). I did find the Fasco Fasfair and the West Systems 105 system. Neither say that they are machinable, but I am guessing if they are sandable, they should also be machinable, right? I am not a fan of the very slow cure time of the west system. Seems like I would have to let the pieces sit to cure over night before being able to machine them. It does allow me to play with the thickness of the epoxy so I can do more of a pour and brush on deal for flatter surfaces. Does anyone have any other recommendations out there?

Thanks!