This is the rudder blade with 1 layer of 160gsm glass.
After glassing, they were given 3 coats of Norglass primer (gray), followed by two coats of undercoat (white). They were rubbed down and flatted between coats. This pic shows how the undercoat also helps fair the irregularities in the surface.
The next step is at least 3 coats of Norglass gloss marine enamel.