Davis FSR Fiberglass Stain Remover, 16 oz. Davis FSR Fiberglass Stain Remover, 16 oz. Ideal for removing oil, rust, exhaust, waterline and transom stains. Also for shower stalls and furniture made of fiberglass. Removes road soil from trailered boats and RV's. Non-abrasive. Safe on white painted surfaces as well as gel coat. Requires no sanding or compounding. Just apply, wait a few minutes and rinse.