Join Date: Dec 2001
Location: Belleville, Illinois
Thanked 22 Times in 17 Posts
Re: por-15 for frame a good or a bad idea?
I've never used POR, but I just finished a frame restoration. I would be worried about the places where two pieces of steel were overlapped and welded. I doubt that any coating applied over the top will completely seal the joint and stop the rust.
Places in question are where the front and rear sections of the inner frame rails are joined near the rear wheel; where the rear crossmembers are laid over the top of the frame tubes and welded on one edge; where the parking brake and muffler bracket is laid over the top of the frame rail and welded on one edge.
There are several more, but you get the idea. Rust in those places takes place between the two lapped pieces of steel. Unless you can bar all air and moisture entry to the area, rust will continue. And doing that will be impossible in most cases. Especially the frame rails where you would have to get inside the frame tubes.
On the inside frame rails, I cut out the lapped places and butt-fit new steel into the opening. In the other places, the rust on the frame rail wasn't as bad, so I cut the overlap off and made a 'T' joint. The rear crossmember took a complete rebuild, so I made all of the joints butt.
After the repairs I had it galvanized. Nothing is forever, but I reckon the frame will outlast me.
If you can't do all of that, use the POR, and do the very best job of surface prep that you can, giving special attention to the overlap areas. It will at least be a lot better than stock.