House of Kolor KDA3000.Q01 DTS Hardener is formulated for use with the KD3000 Series DTS Primer Surfacer/Sealer, a hybrid epoxy two-component primer system used as a Direct to Substrate high or medium build surfacer/sealer. Mixed at a 1:4 ratio (hardener to primer), it delivers excellent adhesion, corrosion resistance, productive dry times, and ease of sanding, with very low VOCs and no isocyanates. Compatible with existing OEM finishes, bare steel, aluminum, fiberglass, galvanized surfaces, and various plastics. Available in a 1 quart can.