When I bought my car it had had an engine fire, I stripped the entire engine bay and por15'd it and then applied new stone chip for a close to oe look. In the fire the left hand wheel arch had also been badly burnt taking off most off the under seal up untill now I havnt done anything with this because I carnt make my mind up how to proceed. The problem is with the engine bay everything was easy to get to with a wire wheel on a grinder so clening up the metal was easy, however under the top of the wheel arch theres an area of panel that dissapers under bump from inside the engine bay where the wing seam's to the inner wing. The underseal in this area is badly burnt and the steel is rusting I could just prep the parts I can see and get to however im worried that if I dont tackle this corrosion I will end up needing an new inner and outer wing down the line.
Heres some pictures of what im talking about.
What do you think the best option is to preserve these panels, would it be best to cut a section of the rear 1/4 out to get to this rust?
or
In the next year or so I intend to have this shell stripped to bare metal by having it sandblasted then acid etch primed, would it be best just to paint what I can get to with por15 to preserve it for now then tackle it better when I have it bare metal'd?
Which I think could still involve cutting a section of panel out as I carnt see any realistic way of getting to the section of seam above the bump. Possibly be better to tackle it by cutting through the inner wing from inside the engine bay so as not to distort the outer 1/4?
Any advice appreciated Steve