In case anyone is interested in doing this or just finding out about POR-15...
The POR-15 comes from a place called Restomotive Laboratories/POR-15, Inc., P.O. Box 1235, Morristown, N.J. 07962-1235. Telephone orders at 1-800-457-6715 (M-F 9 to 5 EST) Website:
http://www.por15.Com
I bought the floorpan kit for $138.50 plus $15.75 shipping. Expensive! I was very intrigued by the promise of no more rust and permanent repair. The kit comes with a bunch of stuff and clear instructions. The website has the instructions in PDF format. It is important to follow the instructions in the right order and the stuff really works! First, there's a degreaser, then a rust neutralizer, followed by a silver rust-preventative paint, and then not one, but two separate topcoats. It takes a schedule of following the procedure in proper order, and the results were a hard black shell that was very gratifying to see in place of the hole that once was. I used the masks that came with the kit, also set up a fan to create ventilation while applying the paint, and heated the area to accelerate the drying process.
They have a very nice full-color catalog that you will get with your order. You might try calling first to ask for a catalog.