Can I Use Silmar 249A or 249-B Polyester Resin to Repair an Epoxy Surfboard?

Can I Use Silmar 249A or 249-B Polyester Resin to Repair an Epoxy Surfboard?

It is generally not recommended to use polyester resin on an epoxy surfboard. Polyester resin does not chemically bond well to cured epoxy laminations, which can lead to poor adhesion, delamination, and a shorter-lasting repair.

Why Polyester Won’t Bond Well to Epoxy

• Chemical incompatibility: Polyester resin relies on styrene crosslinking, which does not react effectively with cured epoxy.
• Surface issues: Even with sanding, the mechanical bond is weaker than epoxy-to-epoxy repairs.
• Durability concerns: Repairs may crack or lift over time under stress or water exposure.

Best Practice for Epoxy Surfboard Repairs

• Use a compatible epoxy surfboard resin for repairs.
• If unsure of your board’s construction, test a small area or contact the manufacturer.
• For polyester boards, Silmar 249A or 249-B is ideal for both laminations and hot coats.