Master Bond polymer system X21 is a specially formulated one component acrylic polymer based resin system for high performance coating, bonding, sealing and impregnation. It contains 50% solvent which readily evaporated upon exposure to air especially at elevated at temperatures. Master Bond polymer system X21 is a very clear solution which air dries extremely fast to form hard colorless films with superior hardness, good abrasion resistance, excellent clarity and color retention even upon prolonged outdoor exposures. This polymer system bonds well in both peel and shear to many similar and dissimilar surfaces including metals, wood, most plastics, ceramics, glass, rubber, paper, leather, wallboard and other insulation products as well as to plastic foams etc. An initial set takes place as soon as a significant amount of the solvent has been removed. Master Bond polymer system X21 does not carbonize upon heating to high temperatures.

All surfaces should be carefully cleaned and dried prior to application. They should be free of grease, oil, dirt and other contaminants for optimal results. Conventional cleaning methods such as solvent washing, vapor degreasing, etching etc are applicable. A convenient way of determining thorough cleaning is to place a few drops of cold water on a "cleaned" surface. If the water forms a continuous film, cleaning is satisfactory.

Master Bond polymer system X21 is readily is a flowable liquid. It can be further reduced in viscosity by adding solvents such as acetone, MEK, toluene etc. so as to best meet specific application needs. Master Bond X21 has excellent water resistance and is a superior electrical insulator.