Isophthalic Gelcoat (White, Marine Grade)

This white isophthalic gelcoat is formulated on an isophthalic unsaturated polyester resin base to deliver superior hydrolytic resistance, weathering durability, and gloss retention compared to orthophthalic grades. Recommended for marine hull construction, deck fittings, and any FRP application that will experience prolonged water immersion or outdoor UV exposure. The isophthalic acid backbone reduces the susceptibility to osmotic blistering that can affect orthophthalic laminates in wet environments, making it the industry standard for recreational boat hulls. Pre-pigmented with high-quality titanium dioxide for a bright, consistent white with excellent opacity and color stability. Cobalt pre-accelerated, the product catalyzes readily with MEKP at 1–2% by weight. Gel time at 20°C and 1.5% MEKP is 25–45 minutes, providing adequate open time for thorough spray or brush application. Post-cure Barcol hardness of 42–50 reflects the higher crosslink density from the isophthalic resin. Gloss retention after outdoor weathering is significantly better than orthophthalic alternatives. The product is compatible with standard polyester and vinyl ester structural laminates applied within the recommended tack window.