We then applied the Metal Ready with one of the supplied brushes to the bare metal and rusted areas and let it sit for approximately 20 minutes making sure that it stayed damp. The Metal Ready will neutralize the rust and etch the metal for better paint adhesion. A water-dampened rag, followed by a clean dry rag, was then used to neutralize the Metal Ready and get the channel ready for paint.
The rusted areas were then painted with the POR-15 paint. Notice that we were repairing minimal rust holes. If you have substantial rust, you might be able to repair it with their Floor Pan and Trunk Resto Kit which includes some fiberglass sheets to cover larger holes.
We allowed the paint to dry overnight and then prepared the putty to fill the holes by cutting off two equal amounts and then thoroughly kneading them together. It's very important that the putty is mixed completely-we added a little bit of water to make it easier.
With the putty sanded smooth, we sanded the entire window channel and painted it all with a coat of the POR-15 paint to make sure that our repair would last. Once the paint dried, the repaired areas were almost undetectable and should last another 30 years.
Once the putty is mixed, it stays workable for about an hour, more than enough time to complete the repair. We simply used our fingers to push the putty into the channel paying particular attention to the areas where the rust holes where.
We let the putty sit overnight to ensure that it had dried thoroughly and then sanded it with some 80-grit sandpaper, followed by some 220-grit. Once we started sanding, the importance of smoothing out the putty while it's still pliable became very apparent. This part is tough.