I am working on a old truck and where the roof panel joins the rear of the cab it is pretty thin. If I was to clean up the seam real well and lead it in would that be a good option or would a modern panel adhesive be a better choice ?
Neither lead nor panel adhesive are gap fillers. I would weld a strip of metal tightly to the inner side of the seam and use plastic filler to sculpt a new seam. It would not require a great deal of filler so cracking should/may not happen. Very important that you kill the rust first with something like SEM Rust Mort.
Lead it and seal the back side with epoxy primer and urethane body sealer. Short of metal finishing in new panels, leading in the seam would be the longest lasting way to repair. Larry
Agree, the panels look almost disconnected from each other. The seam has to be stabilized or any filler you put in it will crack. You could cut the seam out, form an angle strip (like an angle iron so to speak) for each side of the seam and then weld the angle pieces to the panels and then to each other. Basically reconstructing the seam. I usually butt weld everything, but spot welding could be used as well. Sent from my iPhone using The H.A.M.B. mobile app
I'm not sure how well either one will stick to the rust that you'll never get out of that joint. Cut it out and weld in new stuff. You could do it in one piece or 2 with the bent lip. If you want tons of frustration do it in 2, you absolutely need a shrinker stretcher outfit to get it done in two. If you do it in one piece, all you need is hammer and a rock to stretch it. Bench and a post dolly, anvil, rail road track would be easier than a rock.
Looking at the pictures closer[meaning I put my glasses on] you guys are right. It needs to be cut out and replaced. But if the factory seam look is not needed for restoration purposes, he could form a single panel and butt weld it in and in my eye really clean up the look of the cab. Larry
If you went to the trouble of getting it clean enough to lead you would still have to weld the gap to keep it from moving.I would make a strip that looks like the stock body line and cut out the bad and add that to it.Or find a donor roof and cut the piece out from that one and weld in.Or another roof all together maybe.
I messed up my above response but thanks for the input, it gives me another direction to go with the repair that I had not considered. This is my first build with something this old and in this condition.
I have used panel adhesive before. 3M 08115. I did some tests on sheet metal and was impressed how strong it is on sandblasted metal. On a long Seam like that, it will be difficult to clamp and get good contact. Almost have to drill a lot of holes and use screws to hold together while it cures. I also found that using a heat gun during the clamping process helped thin the glue out so the two pieces would mate together well. Not too much heat or it well cure. I used it in a place where I did not want the heat of welding to burn paint off in areas where I couldn't get at it. These adhesives are expensive also. If there is any rust left, I would worry about it rusting years later and causing the adhesive to let go. Sent from my iPhone using H.A.M.B.
Cut it out and replace it! Lead and adhesive have their uses bit this ain't one of em, do it once and do it right! Sent from my SM-G935V using The H.A.M.B. mobile app
first thing I'd do is blast that rusty crack and see if there is any metal in there when I was done. the whole cab looks like it needs to be dipped or blasted. if you just want to keep the rain off the back of your head use JB weld.
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