I am trying to glue my plastic radiator tank using Elmer's
Polyurethane Glue just to see if it'll hold. I've heard that this
worked fine on small pinhole leaks by a few people. The
problem is that when ever the glue dries bubbles or foams
are formed on the glue in about 2 hours. The foam is a bad
thing because it's very brittle. What is the proper way to use
this glue so it won't foam?

Thanks