Abstract: This invention relates to an adhesive for use in forming laminates of polyester impregnated fiberglass. This adhesive comprises a reaction mixture of 100 parts of a reactive hydrogen containing polymeric material of about 700 to 4500 molecular weight selected from the class consisting of polyester polyols, polyether polyols and polyester amides, an organic polyisocyanate, at least 5 parts to no more than about 200 parts of an inert powdery filler with the proviso that the filler shall not exceed that amount which renders the resulting mixture unspreadable and sufficient monomeric nitrogen containing polyol having 3 to 6 hydroxyls to be essentially equivalent to the excess polyisocyanate. Catalysts of the tin and amine type may be utilized, if desired. Amounts of 38, 52 and 80 parts of organic polyisocyanate per 100 parts of the polymeric material are some of the levels used in some of the examples.