WELDCRETE BONDING AGENT 1-GAL. Weld-Crete is a unique chemical bonding agent that incorporates a proprietary polyvinyl acetate homopolymer formulation. Its main function is to join internal and external concrete, walls, floors, ramps, beams, steps and structurally solid columns. Furthermore, it is very effective for gluing stucco, mosaic and laying layers on all internal and external surfaces, as long as they are solid.