PT2050 is a medium viscosity, unfilled, light amber laminating resin that is designed for structural production applications. When used with the four hardeners listed here, the combinations provide excellent wet-out of fiberglass, carbon and aramid fibers. Special additives have been incorporated into these products to promote chemical adhesion to fabrics made with these fibers. Typical applications include aircraft and sail plane skins and structural components, auto bodies, radomes and prototype parts. Hardeners PT2050-B1 and PT2050-B2 are the standard production hardeners for fabricating composite parts. PT2050-B1 has a one hour working time, and PT2050- B2 has been developed to provide a longer working time for larger and/or more complicated laminates when needed. Both of these hardeners will cure completely at room temperature without additional heat. PT2050-B is a faster setting hardener that can be used for patching and repairs, and smaller laminates. PT2050-B has a similar viscosity to PT2050-B1 and PT2050-B2, so handling will be similar, except for the faster cure. PT2050-B3 is a newer addition to our Tooling line that offers some unique characteristics for certain uses. The mixed viscosity of the system when using PT2050- B3 is considerably lower than other laminating hardeners. This allows easy penetration of thicker fabrics during hand lay-up, and provides a good system for the infusion process. Also, even though it has a working time 50% longer than PT2050 Part B1, it cures to a harder state overnight than when using the B1 Hardener. Cured properties with the PT2050-B3 are very similar to the high values obtained with the other Parts B of the PT2050 system. These products can be considered low toxicity materials that have minimum hazard potential when used properly and in a clean and responsible manner. PT2050 does not contain any hazardous diluents or extenders. Hardeners PT2050-B, PT2050-B1, PT2050-B2 and PT2050-B3 do not contain methylene dianiline ( MDA), or other potentially harmful aniline derivatives. Neither the resin or the hardeners will crystallize in normal shipping and storage conditions. Both components have excellent moisture resistance, for minimal problems in high humidity environments.