Rear transition pan metal work, part 1 - Drivers Side pan patches, holes, and cracks

There's lots of work to do in this area, so I'll break it into parts. Overall, from start (here) to finish (primed metal) took two and a half months of working on it every few days for a few hours at a time. I'd be faster if I knew what I was doing.

First, gotta clean up the surfaces and strip them down to bare metal so I can weld on them. Top and bottom surfaces get stripped with a combination of wire wheel and strip-it disc.

Inside:

Outside:

I'm going to fill the holes from the old exhaust screws and those weird sheet metal screws and weld the crack shut, but first the gap between the floor pan and transition pan needs to be closed up. For whatever reason (stress), there's some separation between these pieces - maybe 3 mm or so, but in order to weld those holes shut properly they need to be snugged up tight. My Bright Idea is to pull the gap in with some grade 8 nuts and bolts. This works eventually, but 14 gauge metal doesn't want to move easily. Fortunately, I have some freakishly large arms and amazing kung-fu grip, so I got them close.

I had to drill the holes out a little to fit the bolts in and then tightened until I closed the gap (mostly). Then close up the holes by removing one bolt/nut pair at a time and weld that hole shut.  That extra-looking piece at the bottom of the pic above is a spacer - it won't stay.  And for fun and good measure, I added some extra welds at the seam. Not stock, but stronger. Eventually that seam where the panels meet gets covered up in 'seam-sealer', really just a fancy sort of caulking for auto body work.

Here's a close up of the crack in the transition pan - also visible are the holes that were left from the sheet metal screws.

The crack gets welded shut in two steps - first, a hole is drilled at the top of the crack to keep it from spreading (a 'stop-drill') and then welded shut from the top the bottom. It looks rough now, but I'll come back and smooth this out later.

Next up is the giant hold that used to be a seat belt bracket.

The hole is traced and cut out and fitted with a square patch piece of 18 gauge metal.....

...butt-welded in place...

...dressed the welds ....

...and Blam-o, it's patched!  And, yes, a square patch is way easier than that last one I did. Then I screwed up filling in one of the holes under my pretty new patch and had to cut and weld another mini-patch to fill it. So, the penalty for cockiness is more practice.

I also drilled new, correct holes for the replacement seat belt bracket and the dual exhaust hanger bracket.

Except for clean-up grinding, metal work is done on this side; next up is the passenger side, and then upper section that has a long list of little issues to fix.