I have a bottle of Powerlock that's just 3 years old. I used it about a month ago and it worked fine. I tried to use it again a few days ago and it won't dry, it stays wet for a long time, like over 2 hours. The weather is in the sixties but I've tried it in the house and it won't dry there either. What could be wrong? Do sealants that get old have this kind of thing happen? I'm baffled. Thanks in advance!