The cure of polymeric diphenylmethane diisocyanate (pMDI)/wood bondline in a controlled saturated steam environment was monitored using micro-dielectric analysis (mu DEA). Saturated steam environments were produced between 110 degrees and 140 degreesC. The degree of cure calculated from mu DEA was a basis for further spectroscopic, calorimetric, and mechanical evaluation. Interpretation of calorimetric and spectroscopic analysis revealed large consumption of isocyanate early in cure. However, mechanical strength, as revealed by lap-shear tests, did not develop until late in cure. Low lap-shear strengths and a plateau in conversion rates were detected for samples pressed at 110 degrees and 120 degreesC. Several components of the analysis suggest that low temperature cure may result in crystal formation, leading to diffusion controlled cure.