Inconsistency of curing Polyurethanes and Moisture Polyurethanes can be effected by atmospheric moisture. Common effects of moisture contamination can appear as excessive 'air bubbles to foaming' during cure. Moisture in polyurethanes will cause foaming.
To reduce the contamination moisture is to decant the polyurethane from container and replace the cap immediately. Ensure that temperature of polyurethane and working environment is as stated on the technical Data Sheet (TDS) do not allow any decanted polyurethane to stand for any length of time.
Polyurethane Weeping After Cure Polyurethanes are a complex blend of chemicals. High and low temperatures and long time storage can cause separation of these chemicals. As cream in milk will migrate to the top so some chemicals in polyurethanes will do the same. The result of chemical separation can cause: a) Sweating after cure b) Reduced phase change (A change from transparent mix to opaque after cure) c) Inconsistency of curing
To solve these problems a thorough shaking or stirring of the polyurethane will re-blend the chemistry together.