Gelcoat won't cure properly on its own because it needs help to overcome air exposure. You'll need either wax or a catalyst (MEKP) to ensure it hardens. Wax creates a surface barrier for open mold repairs, while MEKP chemically cures the gelcoat for closed molds or thicker layers.

Easiest Option: Topcoat Additive

• Smooth, nearly "walk-away" finish
• No need for PVA or wax

Classic Approach: Surfacing Agent (Wax)

• Add at 4% ratio
• Forms a barrier, allowing gelcoat to cure

What's the Difference?

• Surfacing Agent: Traditional wax additive requiring more finishing steps
• Topcoat Additive: Advanced additive for faster, cleaner finish

How to Choose

Consider project size, shape of mold, and always follow the manufacturer's catalyst and wax recommendations. Reminder: Catalyst is always needed.