Gelcoat is a 2 part polyester resin primarily used to finish the fiberglass surfaces of boats, aircraft and swimming pools. It is available in a liquid resin as well as a paste form and provides a slick, shiny finish to protect the fiberglass from damage by ultraviolet light, water or abrasions. If you are filling in scratches or cracks, it is a fairly simple but labor intensive job that can be performed by using a paint brush to apply gelcoat. However, if you are planning on applying gelcoat to a large motorboat or airplane, be aware that it is meticulous, exacting work requiring the application of 4 layers of gelcoat as well as multiple sanding operations.
