Master Bond X21 is a specially formulated one component system for bonding and priming polyolefinic surfaces. X21 is a very low viscosity(<250 cps) solvent based system that is easy to apply and process. Most often, it is used as a primer to promote adhesion of polyolefinic substrates to other kinds of materials, such as metals, ceramics, composites and other kinds of plastics. When employed as a primer, X21 is applied in a very thin layer on to the polyolefinic piece and the solvent allowed to evaporate. This will take place typically in 2-4 hours and can be greatly accelerated by adding heat (15-30 minutes at 150-200°F). After the surface is primed in this manner, an epoxy or silicone is prepared and applied to the substrates, and then allowed to cure. When used in this fashion, X21 is, in essence, a bonding promoter, allowing adhesion to this low energy type of plastic (polyolefin) in a process that is relatively simple and straightforward.