GEL COATING VS. POLYURETHANE FINISHES – WHAT’S THE DIFFERENCE?

  1. Most manufacturers of all-fiberglass industrial doors use gel coat as the surface finish provided on their exterior door and frame products. Regardless what these door makers may say about the performance or appearance of this surface finish, its use is driven by manufacturing considerations, not aesthetic or product performance advantages. Gel Coat is a pigmented polyester resin used in open molding, bag molding, and resin transfer molding processes. It serves as a release agent to prevent the piece part from sticking to the mold in which it is being made. Before adding the liquid resin, a wax is applied to the mold. Without gel coat, the liquid resin would eat through the wax applied to the surface of the mold and would bond to the mold itself. Gel coat cures too quickly to attack the wax layer so the finished molded door will not adhere in the mold.

    At Special-Lite, we use an Aliphatic Polyurethane Coatings on our Pultruded, All-Fiberglass products because they are the highest quality industrial finish available on the market today.This finish is used worldwide for the toughest applications, from off-shore oil rigs to amusement parks to industrial plants. Polyurethane finishes have superior UV protection and resistance to airborne corrosive agents, and are not susceptible to chalking, discoloration, or leaching. They maintain a high gloss appearance and flexibility for many years, even in full sun exposure and corrosive environments.

    Repair of surface damage is easy with Special-Lite’s All-Fiberglass products. Any body filler suitable for use on fiberglass can be used to repair damaged areas, and polyurethane can be applied using conventional
    methods to repair the finish. The finish on these products is applied to a thickness of 5 mils. We offer 10 standard colors, and can match custom colors, or provide a primed finish only.

    Contact us for more information or to discuss your project!

    AF Series Standard Colors