Floor Pans- Rust prevention and Tunnel treatement, advice needed Options

[highways]

Hi all,

I'm working on my floor pans... I have them wire brushed down to bare metal. They are in overall decent shape though there is some rust around the perimeter where they meet the longitudinals. These corners seem innaccesable to all but a small wire brush (toothbrush size). Question is:

1. Should I apply POR 15 Surface Prep, then POR 15 to get in cracks, then Seam Sealer, then maybe another coat of POR 15 over Seam Sealer?

2. Or, should i just do Seam Sealer first over bare metal, partial rust areas around the perimeter? Then follow with POR 15?

Second question... the smaller 'cross tunnel'.. the one where the front seat adjustment bracket mounts, is in poor shape. Rust inside it looks bad... some of the lower edges are gone but it's still largely inaccesable to any tools or painting. I think my options are:

A. Drill some holes in top, blow it out, and spray as much paint in there as I can and call it a day.

B. Cut it out and weld in replacement. But is this part even available? And still how do you paint the bare metal inside after you've welded a new piece in?

Any advice would be appreciated.

[Gudhjem]

Great info in this thread. I am staring to close up my longs, firewall bulkhead and some other cavities, so was reviewing all this info.

The rinse-with-water-and-let-dry part of the process scares me. I wouldn't have considered it, except that at least three guys in this thread with 100x more experience than me are doing it. Running a water hose through my longs (IMG:style_emoticons/default/unsure.gif). Guess I'll be doing that as well.

For Scotty B., I thought I read that in your opinion rust encapsulators (not converters) are snakeoil, don't bother, but here you say that's how you finish off the process. Is that true just for cavities, where other options are limited? Or maybe what you are saying is that they are okay if you get rid off all the rust first, just don't use them to actually encapsulate rust?