Hole at mudsill and clearing out fresh air duct

I decided to start tackling the fresh air ducts today. I started some of the prep work a few years back, but never fully cut out all the bits and pieces. After about two hours of cutting and grinding, my arms were killing me. Holding a 7" grinder into a wheel well is more exhausting than I would have guessed. I was able to get about 90% of the metal cut out. I'll get the rest of it later this week.

After my arms were dead, I decided to work on something topside, so I repaired a couple holes around the gas filler. They were in the typical spot above the mud sills. The paint was bubbled up there, so I figured someone had filled them up with bondo... I figured correctly.

I also got to test out my new autodarkening helmet today. $40 on ebay. The glass is MUCH clearer than the one I bought 6 years ago (now broken). My sheetmetal welding abilities are much greater with a helmet like this rather than a fixed lens.

Fresh air duct partially removed from a few years ago
90% completed

Bubbles in the paint... You know what that means!

Repair area. The patch is on the right.

Area welded up ready for grinding

Area ground down and finished.