Any suggestions on how to finish the seams on the rear deck of a 72 convertible? I just repainted mine because of a crack in this area and one side has already cracked again.I used body filler to smooth the seams and this did not work.Any suggestions? How were these seams finished from the factory? Thanks Glenn
They were spot welded at the factory and then finished with lead. Cracking has always been a problem with the convertibles. I always remove the lead and weld the seams solid before finishing them and have never had one crack after that.
Using plastic (Bondo, Dura Glas, etc.) on any flexible areas will result in it cracking. That's why lead was used, its flexible because its soft. One suggestion that MIGHT work, is try using a flexible 2k (2 part) bumper repair filler material. I do know its flexible, it sticks ( to plastic ) and sands pretty well. I've never used it on steel tho, these newer cars have a pretty damn ridged body structure, unlike our older body on frame cars that twist and flex like a wet noodle.
Almost all the convertibles crack there. My 70 442 convertible is one of the few that has not cracked. Many guys weld that entire seam shut when repainting cars to stop the problem. Duane
I cant think of the manufacturer. 3m makes some and theres another manufacturer or two that make it. Evercoat makes a flexible glazing putty, but that's for doing skim coats, not for filling.
The problem with those seams is that they flex at those points due to the body not being as rigid as a Coupe body would be. I don't believe something with a "flexing" agent will do anything. If you don't believe me all you need to do is see how the paint sticks on a bucket seat headrest after it gets slamed into the steering wheel once too many times...............or look at a bumper cover where it gets creased, and watch the paint crack. If you are going to spend the money to repair it so the paint won't crack, just weld it and be done with it. Anything else is smply taking a chance. Your money, your call. Duane
I agree 100% with this. IMO, you'll just be looking at fixing it again next year. Or sooner. I've always been a firm believer in doing it right the first time rather than having to do it over. If GM would have done it right the first time, no one would ever have had to deal with it again.
...one of the benefits of convertible ownership...along with seeing bugs on windshield dance back and forth as cowl shakes, and not getting fingers pinched in door gaps...:grin: Learned about "convertible shake" in '60s doing new car prep. Windshields were full of those little colored inspection stickers, making convertible/hardtop rigidity difference stand out during road testing.
I think my 70 Skylark convertible was welded, before I received it from my uncle it did not have a seam or style line it was smooth. When I had the car repainted old paint was striped to bare metal and I remember seeing this smooth bare metal no obvious filler no seam or style line in this area. The paint and or clear coat has cracked. It is really only noticeable with changes in temperature. Was there originally a seam or style between the quarter and the rear deck, similar to the rear quarter extension area or was it smooth from the factory? I have noticed on hard top versions there is a seam between the rear deck and quarter. I have been contemplating having a seam put back in at least then when the paint cracks it would be in the seam. I would throw in a picture or two, but uploader still not working. Any idea when this bug will be fixed?
Mine are mig-welded solid (as opposed to spot) and re-leaded. No issues so far, but the car hasn't been driven much in the 7 years since it was done.
No, there was no seam on the convertible like there is on a hardtop. The convertible, once spot welded, was filled with lead and smoothed. The hardtop seams were visible and were filled with seam sealer, which is pretty flexible, so they didn't have a tendency to crack.
That seam is pretty deep,I'm afraid of warping the panel.Does it have to be welded solid from top to bottom filling the seam totally with wire? Or do you mean weld it across the top of the seam with a stitch weld and then use filler to finish it? Glenn
Can someone post some pics of the seam area and of worked done to it or entire replacement of this section. My vert may have the same issues i think someone filled it with bondo. Since my rear trunk area has more rust I was planning on replacing it , they have now a repo. metal for the verts. Thanks,
If you have a 70-72 Skylark/GS a-body convertible, the panel between the rear window and the trunk lid is the same as a 68-72 Chevelle. Duane
Have any of the convertible seams mentioned above cracked by now? I'm reviving this old thread because, in 1989, I removed all the original lead from these seams, welded them completely, and smoothed the area with new lead. When I drove to Bowling Green in 1991 from Colorado, they both had cracked again before I got home. Now I didn't replace the body bushings in 1989, so perhaps that would have helped? -mike
The 3M Panel Bond (08115) that Ethan mentioned is the superior product/process to eliminate these seam lines. Will flex a little bit, to prevent cracking, and will not promote rust/or cause warpage.. and it stronger than welding. We did a couple of ragtops a decade or so ago with this method, one was a show car, but the other was driven a bunch.. and to my knowledge neither of them ever cracked again. JW
