On this page, you will find our complete selection of polyester resins. Polyester resin is a versatile material widely used in the composites industry, including in the manufacture of boats and tanks. When combined with a reinforcement such as fiberglass, it forms a strong and durable composite structure. Polyester resin cures at room temperature with a peroxide catalyst. The curing process takes place in three stages: gelation, curing, and post-curing. Heat treatment improves the material’s final properties.