There were 2 areas of rust perforation that required fixing
Rust Perforation Area 1
The first area needing repair was on the right frame rail immediately in front of the rear wheel. The perforated area was about 8 inches long on the outside of the rail and about 10 inches long on the bottom of the frame rail.
Rust Perforation Area 2
The second area needing repair was on the left frame rail at the rear behind the rear wheel. The perforated area was about 10 inches long on the inside of the rail and about 14 inches long on the bottom of the frame rail.
Making A Repair Template
The first step is to make cardboard templates of the steel used to make the repair. If possible do not cover over any exiting holes in the frame. If you must cover over a hole make the hole in the new steel to match the existing frame. I made a template for the side and bottom of each repair. When I was satisfied with the templates I laid them out on a sheet of 16 gauge steel and marked the shape with a marker. I used a plasma cutter to cut out the shapes and then cleaned then up with a bench grinder.
Cutting The Rusty Frame Away
I used a grinder with a thin cutting wheel to cut out along the marks. Make sure that all of the rusty areas are cut back to good steel. I used toggle clamps and C-clamps to secure the new steel in place. When all was in place I used a grinder with a grinding wheel to groove into the steel on both the patch and the frame. I then welded the grooved areas, removed the clamps, and grooved out the clamped areas. Weld in all of the patched and grooved cracks. Go slow and let the welds cool so you do not burn holes in your repair.
Grind Your Welds Smooth
Grind the welds smooth to the surface of the frame. The goal here is to make the repair look like the rest of the frame. Once all smoothed out you can prime and sand smooth to remove the grinding marks
Paint The Frame
I use a Anti-Rust paint called Por-15. The frame is brush painted