Definition - What does Gelcoat mean?
A gelcoat is a surface layer of polyester located within the structure of fiberglass. Gelcoats are applied by spraying or brushing to provide a hardened protective surface and aid corrosion or degradation occurrence.
Corrosionpedia explains Gelcoat
Gelcoats are used in a variety of construction and corrosion prevention applications, most notably in the production of boats in which the gelcoat surface applied must be fully cured. Coat surfaces are typically between 0.25 and 0.50 mm.