Well I thought this was going to be easy….

Just wipe down the existing oversprayed yellow areas in the rear under quarters, and recoat with some undercoating.  Alas, as I started wiping it down, I saw it flex!  It was no longer attached to the surface underneath.  The old undercoat was no longer sticking.  So went at it with screwdriver, half expecting to find lots of surface rust underneath.

Thats the pile of what I scraped off.  But lo and behold, underneath, NO rust, just lots and lots of ORIGINAL yellow painted steel.  Ziebart might be a lot of ugly things, but it sure does the job.  That steel in the rear wheel wells is 34+ years old, and still has shiny original yellow paint on it!!

Scraped off all the loose stuff.  I sat down inside each wheel well and closely examined the lip edge.  This is where the outside sheet metal is welded to the wheel tub.  Classic rust area.  This is the rust that causes those bubbles in the paint just around the rear wheel well, that you see so often.  Everything looked pretty good, except I found two holes in the wheel tub that were drilled through, from trying to fix the outside steel.  Sigh.  And this little seam opening gem.

So this is from inside the wheel well looking out.  The putty in the left is where I’m fixing one of the drilled holes.  Check out the seam gap here.  Already put some silver POR15 in when photo was taken.  This is CLASSIC spot for water to seep in and start the rot process.  After 2 or 3 coats of POR15 dry in there, I’ll fill it with putty to keep all the water out.  Very lucky I found it.  There were some other minor openings, but filled those with paint alone.

The right side had no seam issues, so was able today to finish that with undercoating.  That was same one all the scrapings photographed came out of.