Dust on the board will cause pin holes. Before seal coating brush or blow the board off and wipe with denatured alcohol on a clean rag to pick up any remaining dust particles. Make sure to use 3 oz of mixed resin per board foot for proper seal coat thickness. If the seal coat is laid on thick enough it will bury any potential pin holes and fish eyes with it's surface tension.For now just give it a light sand, clean the surface, and you can simply squeegee a small batch of resin over the pin holes to fill them.