Resin

Composites

Resin

Resin (in composites) is a polymer liquid that binds reinforcement fibers (glass, carbon, aramid) into a solid composite when it cures. Resins penetrate and wet the fibers, then harden—usually by a chemical reaction or heat—producing a stiff, durable, load‑carrying matrix.

Resin Types

Polyester

Overview: Polyester resin is the industry’s most common, cost effective composite resin. It cures with MEKP and provides quick, reliable laminating for general-purpose composite work.
Characteristics: Polyester resin cures quickly and provides good dimensional stability; it is available as ortho (general) and ISO (higher‑grade, stiffer, more corrosion‑resistant) types, produces a tacky surface unless a surfacing agent or finishing resin is used, and is easy to work with for hand lay‑up and spray‑up processes.

Epoxy

Overview: Epoxy resin is a high‑performance, two‑part resin (resin A + hardener B) used for lightweight, high‑strength composite parts. It offers excellent adhesion, water resistance and superior mechanical properties compared with polyester.
Characteristics: It offers excellent bond strength, low shrinkage and fast wet-out of reinforcements, and it fully cures to a hard surface. Epoxy is not compatible with chopped strand mat (CSM), but it works well with carbon fiber, Kevlar and fiberglass cloth.

How It's Used

Usage and Applications

Polyester laminating resin is Fibre Tech’s most widely used resin for general-purpose composite work. Affordable and easy to work with, it cures quickly to add dimensional stability and is ideal for applications such as boat hulls, automotive body panels, kayaks, surfboards, patio decks and many molded parts. Polyester resin is compatible with fiberglass reinforcements and is catalyzed with MEKP hardener.

Usage / Applications

Boat construction and repair
Fiberglass molding, fabrication and repair
Spray-up and hand lay-up
Base for fairing putties and structural compounds

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