Use Pentra-Hard Densifier to harden and dustproof new and existing concrete. When sprayed, the water-based solution penetrates into the concrete and reacts with free calcium to form insoluble calcium silica hydrate. This makes the concrete more resistant to water, stains, and abrasions, and provides for easier maintenance over the life of the surface. The product also can be used for concrete polishing. Dayton Superior. 800-745-3700.