I know this is a really old post but I need to treat the frame rails on a couple of cars and wondering if there's any better ideas/products on the market now to deal with this issue. I have the floor pans removed on my cars so it's easy to get inside the rails except for the front rails inside the engine bay. Also need to treat the inside of the rockers.

There doesn't seem to be a lot of good opinions of POR-15 judging from the earlier posts. I also remember a member on here several years back that was trying to develop a spray rig to get POR-15 inside the frame rails and other inaccessible areas.

So what are you all doing to treat yours?

Jim