Finally finished my leafspring relocation/torqueboxes and frame ties

That's a lot of work. I used 50 year rated black roof sealant in a caulking tube to seal and smooth out the seams. Helps keep water and such out of them, makes it more visually appealing and it's paintable.

Welding upside down on dissimilar metal thickness's took some experimenting for me. I ended up switching polarity on my welder and using a stitch welding technique. I started the puddles on the thicker metal and then swept up to pool it onto the thinner sheetmetal. It smoothed things out a lot.