9-27-03 - Well, I'm a little late on this update. The pictures you see here were actually taken about a month ago, but I haven't had time lately to get this page constructed and the pictures processed due to many other things going on. I finished getting the yellow '70 on the previous page stripped down. I rolled the cab off the frame onto the shop floor, making sure it was upside down, for easy access to the bottom side. Why?

Well, I'm going to be needing some patch panels after all. Remember that blue '68 cab I was going to get that was almost rust-free? I'm embarrassed to admit that I didn't check it out as closely as I should have...it's not as rust-free as I originally thought. In fact, it's about as bad as the others I've run across...and in some ways almost worse, because there's firewall rust that some of the others didn't have. However, I'm tired of messing around with the whole thing, so I'm going to just fix this cab with replacement panels and get this project done! This could turn out to be beneficial for those of you following this project, because now you're going to get a lesson on how to replace floorpans...and cab corners...and front cab mounts.

Anyway, I got the cab cleaned up and began to survey the damage. There was rust in both floorpans which will require complete replacement. There is some semi-serious rust repair needed along the firewall on both sides at the lower seam, despite the thick undercoating, and both cab corners are toast.

After getting the '68 cab stripped and cleaned out.

A shot of the inside of the passenger side firewall. (Click for a full version also showing the floorpan damage.)

The heavy undercoating actually made things worse, by trapping moisture along the firewall and eating away at the sheetmetal. This is a before shot of the passenger side damage, prior to heating and scraping the undercoating.

I was originally planning on trying to salvage the cab corners from the yellow cab, but after spending some time trying to cut the old ones out and taking a look at what I'd be in store for trying to fix them, I decided to just spend the $20/each to get replacement pieces.

Using a torch, I heated up the undercoating and scraped it off the firewall, and then cut firewall patch panels from the '70 cab, as shown here. Keep in mind that this cab is going to be completely sandblasted, as are the patch panels I cut, so the patch panels shown here are very rough at the moment.

Here's the passenger-side firewall after cleaning off the undercoating and trimming out the rust, using an air hammer with sheetmetal attachment. I plan to weld a patch panel using a lap weld with about a 1/4" overlap, using a Hobart 175-amp MIG welder.

At first I was going to fabricate my own floorpans, so I cut out the rusted piece from my cab and cut new ones from heavy sheetmetal I had laying around the shop. After trial-fitting the 'new' floorpans, I discovered that the floorpan wouldn't be shaped right to allow the new cab mounts to fit properly along the bottom, so I'll be spending the money to buy regular replacement floorpans.