I got a tour of a manufacturing facility making fiberglass fan stacks for industrial cooling towers. These were panels that when bolted together would form a cone about 30' in diameter and about 10' high IIRC. The procedure was spraying the molds with gelcoat and then spraying on the fiberglass using a chopper gun that mixed resin and fiberglass chopped from rolls of fiberglass strip. What a filthy mess. The stench from the resin was unbelievable. There were fiberglass fibers floating around everywhere. Unbelievable. Right then and there I got a whole new appreciation for any firm that produces large scale fiberglass components.