Need to know which printed material might be able to be sanded/finished smooth with release agent for pulling fiberglass mold off of and or a material that might have release properties with fiberglass.
I'd also like to know a recommended material for patterns for making hard fiberglass molds. Ideally, it should be watertight or sealable with paint, and stable at temperatures up to 160 degrees F. Thanks for the suggestions!
For mold release, Silicone Cooking Spray will to the trick for the DIY project. For a production type situation, contact Zyvax and look at their product line.
That all kinda depends on the nature of the model, level of detail, etc. Strong & Flexible and Alumide are porous and would require sealing. Stainless and unpolished versions of brass and silver have significant surface texture for moulding. I highly recommend browsing through the "Shop" tab, taking special note of the materials' finishes, as well as the "Material Portfolio" for design limitations.