Fiberglass Molding

Fiberglass molded parts are strong, long lasting and cost effective. Whether you need open or closed molding, chopped or hand laid, we help you make the right decision for your product application. For boat applications, hand laid fiberglass molding is often the process of choice. Parts can be produced with a high end, class-A automotive finish straight out of the mold or made for a paintable surface. Forte has the experience and knowledge of the custom fiberglass molding process to create the part or product for your unique requirements.

Fiberglass & Polyester Resin Molding Materials

Fiberglass molding materials include: Vinyl Ester Resin, Polyester Resin, Fiberglass Roving, Fiberglass Mat, and Gel Coat. Each fiberglass molding material has different advantages. Polyester resin is the most commonly used material for fiberglass molding, but vinyl ester resin has a number of superior qualities such as heat and water resistance.

○ Vinyl Ester Resin ○

    Vinyl Ester Resins typically exhibit excellent heat resistance, great water resistance, and extreme toughness. This resin is widely used in automotive, aircraft, heavy construction, and tooling applications.

    Polyester Resins are the most widely used; particularly in the marine industry. The majority of dinghies, yachts, recreational boats, and jet skis use of this resin.

    Fiberglass Roving is used as the main strength in reinforcing parts. The roving is fed through a “chop gun” which cuts the roving into strands typically 1” to 2” inches in length. The strands are sprayed in conjunction with the fiberglass resin in a crisscross pattern to ensure proper overlapping of the strands for strengthening purposes.

    Fiberglass Mat is used in the hand lay-up process. This process consists of using layers of resin soaked fiberglass matting. Hand-laid parts are very strong and provide consistent wall thickness throughout the part

    Gel coat is the material used to provide a high-quality finish on the visible surface of a fiberglass reinforced composite product. It has the ability to be as shiny as paint on a new car with a class A finish. This material comes in any color and is used for boats, engine cowlings, and heavy construction products.

Open Mold Fiberglass Process

Open mold methods allow for a rapid product development cycle because the tooling fabrication process is simple and relatively low cost. The open mold process involves spray painting a gel coat or hand laid fiberglass roving onto a mold. After the gel coat and resin are applied, all entrapped air must be removed between the layers to avoid weak spots and solidify the composite. Once the air is removed the part is left to cure, then de-molded and trimmed into a finished product. Additional layers of mat or woven roving and resin can be added for thickness.

Closed Mold Fiberglass Process

Closed molding processes are ideal for efficient fabrication of consistent, quality parts at medium and high volume, with little waste and harmful emissions. Closed molding uses a predetermined amount of resin that is introduced into the closed cavity using a vacuum. Once the laminate is cured, the mold is opened and the part is removed. This method produces parts with a better cosmetic surface and it requires less secondary work.

Applications for Fiberglass Molding

Fiberglass molding has countless applications, a few common uses are below:
• Boat hulls and decks
• Engine cowlings
• Lawn and garden products
• Heavy construction components
• Radiators
• Bridges
• Furniture
• Auto parts

Benefits of Fiberglass Molding

Strong & long lasting Design Freedom 
Alluring visual appearance Very low thermal conductivity
Resistant to environmental changes and damaging conditions
○ Impact resistant

Paddle Boat

Fan Shrouds

  Duct Cover

Heavy Equipment Cover