Fiberglass Gel Coat Replacement Powders

Question:

We currently manufacture fiberglass products with a gel coat finishing system and are looking at alternatives to this gel coat system. Are there any low-temperature powder coating products that would be suitable for fiberglass? Maximum substrate temperature would need to be relatively low (e.g. < 250°F) and I understand there are IR or UV options to achieve this. The product is industrial and therefore the standard of finish is not critical. A. R.

Answer:

The process you are describing is called “in-mold powder coating.” This process was pioneered by Ferro Corporation (now Akzo Nobel) as a replacement for gel coat. The process was used in SMC (sheet molded compounds) fiberglass operations where fiberglass parts are made in steel molds under high pressure and temperature. The powder coating was sprayed into the mold first and then the fiberglass/resin bats were added before the mold was closed (male and female molds) and was heated above 200°F under hydraulic pressure. The part was ejected from the mold completely formed, coated and cured. This is the only gel coat replacement technology that uses powder coatings that I am aware of.

However, powder coatings have been applied over gel coated fiberglass parts. This process uses low-cure powder coatings and IR or UV cure systems (ovens). The powder is spray applied onto the product and then cured. This is mainly used as a liquid paint replacement technology and not as a gel coat replacement technology.