What type of tooling gel coat should be used for mold construction?

Tooling gel coat selection directly impacts mold surface quality, durability, and heat resistance. Isophthalic polyester tooling gel coats provide the highest natural gloss and smoothness but offer moderate strength and heat distortion temperature (HDT).

Vinyl ester tooling gel coats provide superior strength and higher HDT but slightly reduced gloss. A common best practice is to use an isophthalic gel coat for surface cosmetics, followed by a vinyl ester barrier coat to reinforce strength and surface stability.