The next order of business was to patch an area of the floor I needed to cut open earlier. I had to modify the inner frame rail for my new fuel lines, and this area had to be cut open for access. This section is 3 layers thick - the first two are about 14ga and the top was thin (20ga).
First I cleaned up all the cuts then welded the first layer and ground it smooth. I coated everything in 3M Weld-Thru II primer, which is a decent way to protect the areas in between layers.
Then I formed a piece for the middle layer out of 1/8" steel and welded it in place. The shape still needed some tweaking but turned out OK for something that will never be seen again.
Ground smooth and weld-thru primer sprayed on
Then the top layer of 20ga sheet was butt welded in place and plug welded to the middle layer to recreate the factory spot-weld joint.
The next patch was in the rear wheel arch. I cut away the rot and coated everything with weld thru primer.
This piece couldn't be made from one piece, so I made it from 2 pieces and put a seam down the center where it could be easily blended.
After welding, grinding, drilling plugweld holes, and finishing with the DA.
Plug welded, ground smooth, and primered up.