A Bismuth/zinc carboxylate has previously been reported to be good delayed-action catalysts in two-component urethane systems. In this paper, a bismuth/zinc carboxylate in conjunction with mercaptans as a room temperature curing delayed-action catalyst system will be described. Unlike the organomercury catalysts that have a set delay, it was found that use of the mercaptans in conjunction with the bismuth/zinc carboxylate results in a much greater induction period than the use of the bismuth/zinc carboxylate alone. Increasing the concentration of mercaptan in the presence of the bismuth/zinc carboxylate resulted in a corresponding delay in the onset of gelation, giving the user the benefit of setting the length of the induction period.