Exxen Coatings Fiberglass Filler short strand product. Its lightweight formula can be easily shaped and sanded once cured. Gold color. Non-sagging even on vertical surfaces – spreads, adheres, and finishes like a polyester filler Forms a hard, durable surface that is still smooth and very easy to sand Can be finished with putty or glaze or directly primed Substrates: Fiberglass, steel, plastics