Topcoat, also known as flowcoat is a thick gelcoat based coating mainly used for finishing fibreglass flat roofs and the reverse (fibre) side of fibreglass mouldings. A high quality isophthalic, Lloyds Approved topcoat it has excellent physical properties, water resistance and UV light stability. Pigmentable with polyester pigment paste at 10-15% depending on colour. Not suitable for spray application. Supplied with free catalyst.