Transtar Signature Series Hydrobase DTM Primer is a gray, premium grade, 1K waterborne primer surfacer that performs like a 2K product. Transtar Hydrobase provides exceptional flow and leveling along with superior film build and sanding characteristics. This unique, ready to spray formula is fast drying and may also be used as a sealer. Transtar Hydrobase DTM Primer offers excellent adhesion to a wide variety of substrates and can be directly topcoated with: solvent and waterborne basecoats and clearcoats, single stage urethanes, polyurethane enamels, acrylic enamels, synthetic enamels and acrylic lacquers.