PVA vs Gelcoat Understanding the Differences

When working with polyester resin, PVA (Polyvinyl Alcohol) and gelcoat serve distinct purposes, even though both can be used in similar composite projects. Here’s how they differ: 1. Purpose and Function: PVA (Polyvinyl Alcohol): PVA is primarily used as a mold release agent. It creates a barrier between the mold surface and the resin or gelcoat, preventing the polyester from sticking to the mold. It is a water-soluble film that can be sprayed or brushed on top of molds. PVA is not structural; it does not contribute to the appearance or strength of the final product. Gelcoat: Gelcoat is a finishing material used to provide a smooth, durable, and aesthetically pleasing outer layer for fiberglass or composite parts. It is pigmented and is designed to be the visible, outer surface of the part. Gelcoat provides protection against environmental elements, UV light, and wear. 2. Application: PVA: Applied to molds before casting to ensure easy demolding. It can be easily was