The Stovebolt Site Forums The Shop Area Paint and Body Shop Rusty inner roof; any suggestions?

[IMG]http://i305.photobucket.com/albums/nn214/jfnar/68%20GMC/IMG_0139_zpsn6rhzcsk.jpg[/IMG]
This picture isn't very good but you can tell what I've got to deal with. The other side is just like it and there's also rust above each door. This on a '68 gmc. I have another cab that's rusted out in the floor but the inner roof is good. I plan to cut it out to make patches for this one. The rest of the cab is very solid. I've welded in patch panels before but I've never done this. Any suggestions on how to go about it will be much appreciated. Thanks.

Jeff

It looks like you'll have to pull the glass. Then I'd start by cutting out only what you need from the DONOR cab, then lay your patch panel over the rusty area and use a sharpie to mark the surrounding steel. Cut on the INSIDE of your sharpie line or your gap will be huge, and that's no bueno. Now since I cannot actually see the full extent of the rust on your cab, it may be more feasible to fix the other cab instead. That's up to you though.

Thanks Materman. That's pretty much what I was planning except I plan to cut the bad stuff out first so I'll know for sure how big my patches need to be. Sometimes when I start cutting the bad spot gets bigger. I was planning to cut the patches a little larger than what I remove from the rusty panel; then trace and re-cut the rusty part like you described. Before I weld in the patches I'll try to clean and treat as much of the inside rust as possible. My biggest concern is how much of the pinch-weld area might be rotten when I remove the windshield. I really don't want to cut that part out if I can avoid it. Unfortunately the donor cab is in pretty bad shape in the floor and cab corners. The only good part is the inner roof, whereas my other cab is good everywhere except the inner roof. Thanks again for the advice.

my 58 Viking60 looks like your picture.... the more I poke at it, the worse it gets! Then I drove it in the rain! LOL.... once you get the windshield out, you may find you have some issues on the pinch weld that the gasket is hiding!

You first sand/wire brush/flap grind the whole area looking for solid metal. Also looking for other rusted areas/bubbles. Then decide how a donor piece will fit. Like you said, you always cut it bigger and gradually trim and check, trim and check. When you trim the patch use a non aggressive approach/tool. Like a die grinder. Not an angle grinder. I don't know if you mean there is an inner wall and an outer wall. Anyway, the pinch weld is no harder to "line up" than anything else. Just use a "splint" on it while welding. Pinch welds can be worked/bent some. Watch out for warpage!!!!! I can tell you have the right plan in mind. Grit your teeth and cut it out.