1 Gallon Bondo All Purpose Putty, 2 Part, Professional Strength. Bondo All-Purpose Putty is a professional strength, versatile filler for repairing interior and exterior surfaces around the home. The secret to a fast, permanent repair is in the two-part technology. By mixing the filler with the cream hardener, you can sand the putty in 15 minutes and paint it in only 45 minutes. This fast curing 2-part filler allows you to make high-quality, long-lasting repairs to metal, masonry, concrete, painted wood, plastic, drywall and more. Bondo All-Purpose Putty is slightly thicker than other 2-part fillers, making it ideal for repairing vertical surfaces such as doors, walls and siding. The product is formulated to be non-shrinking, water resistant, permanent and light gray in color once cured. Not only can you fill in small damage, but the strength of this 2-part filler can be used to rebuild rotted or missing pieces of the original surface.