04-21-2010, 11:40 AM
Train nut, is there a date stamped on the can? Most of the spray foam is polyurethane, and I think it has a "life expectancy" where it is still good. If it gets too old, it may have problems. It will probably eventually harden, but it should have a chemical reaction and harden within minutes of spraying. If the store sold you an old can that is beyond the expiration date, you might complain to them and at least get a refund or a replacement can of fresh stuff.