Fiberglass Molding
Why Forté Products for Custom Fiberglass Molding?
Primarily, our customers appreciate our flat organizational hierarchy that promotes direct communication and unparalleled responsiveness. In addition, we represent a turn-key supplier resource in that our 50k sq ft manufacturing plant features both open and closed (LRTM) custom fiberglass molding as well as mold/tooling fabrication. We have particular expertise with applications geared toward engine cowlings, agriculture, and marine. When plastic just isn’t strong enough or pretty enough, fiberglass can be the answer. If you can imagine it, we can mold it for you.
Forté Products Fiberglass Highlights
Open Molding expertise
Closed/LRTM molding
Secondary Assembly Capabilities
In-house mold fabrication
expertise with Marine, Engine Cowlings and Agriculture applications
Class-A Finish capabilities
Engineering “moldability” Assessment
Material expertise with Vinyl Ester Resin, Polyester Resin, Fiberglass Roving, Fiberglass Mat & Gelcoat
Design & Fabrication OF FINISHING FIXTURES
Fiberglass basics
Fiberglass starts as molten glass that’s drawn through tiny holes into filaments. Those filaments are coated (“sized”) for handling and bonding, then formed into rovings, fabrics, or mats used to reinforce resin in composite parts.
• Glass fiber is the reinforcement (strength and stiffness).
• Resin is the matrix (shape, surface, environmental resistance).
• Common reinforcement formats include roving and mat.
Most fiberglass parts are not optically transparent; they can be translucent when made as thin sheets or with clear resin, but fibers scatter light. Fiberglass composites are often RF-transparent, which is why they’re used in radomes.
• Optical transparency (see-through) is uncommon for typical fiberglass parts.
• Translucent panels are a different use-case (light diffusing rather than see-through).
• RF transparency refers to radio/microwave signals, not visible clarity.
Molding processes (open vs closed)
Fiberglass parts are made by placing glass reinforcement into a mold, adding resin to wet-out the fibers (by hand or injection), removing trapped air, curing, then demolding and finishing (trim, drill, bond, paint/gel coat as needed).
• Open molding: the laminate is built on an open mold surface.
• Closed molding (RTM/LRTM): the mold is closed and resin is introduced into the sealed cavity for repeatability and cleaner processing.
• Production readiness usually depends on surface, tolerance, volume and handling constraints.
Mold and tooling (how fiberglass molds are made)
Creating fiberglass molds for production is about repeatability: stable tooling, consistent surfaces, and built-in alignment. Many molds include engineered flanges, locating features, and reinforcement to prevent warping over repeated thermal and mechanical cycles.
• Closed-mold methods (like RTM/LRTM) often require sealing surfaces and controlled resin delivery features.
• Tool stiffness and surface quality drive downstream finishing effort.
• Plan for maintenance: mold release strategy, wear points and surface refurb cycles.