3M™ cream hardener mixes with two-part fillers, putties and glazes to create high quality, long-lasting repairs. When filler and hardener are mixed, a chemical reaction occurs to create a mixture that will deliver a strong, lasting repair. Our hardener is smooth and easy to mix in. 3M™ cream hardener is a hardening agent designed to work with our two-part 3M™ Dynatron™ and Bondo™ fillers, putties and glazes. The creamy consistency mixes easily and quickly. Our hardener combines the best of ease of use and quality final results. The hardeners should not be used by themselves.