While we have used POR-15 for rust problems (and very satisfied with the results); we normally use it for an entirely different function.
Very early in the automotive industry, carburetor floats were made of cork, and then coated with orange shellac to seal the cork. Modern fuel will cut orange shellac about like a heated knife will cut butter! We dip the new floats in POR-15, remove the drips, and allow to air dry. So far, have never had a float failure using this stuff.
Just be sure to read the precautions which come with the product. If you allow any to dry on your skin, you will wear it for weeks!
Jon.
