3M™ Marine Premium Filler is designed specifically for marine filling and fairing jobs including boat fiberglass repair, as well as minor repairs to recreational vehicles. It features a tough vinyl ester formula that is very resistant to water absorption, excellent for long-term performance above and below the waterline. It spreads smoothly for fast, clean filling of minor holes and gaps in fiberglass, as well as wood, aluminum and steel. The two-part filler cures fast with the included 3M™ Marine Cream Hardener– it becomes sandable in 30 minutes –and easily sands to a smooth finish for efficient fairing and filling, so you can get back out on the water or the road. 3M™ Marine Premium Filler is also great for achieving a smooth, sandable surface over reinforced fillers such as 3M™ Marine High Strength Repair Filler.