When did GM stop using lead compounds when mounting the tops of cars? On the older cars we often see this at where the top meets the A, B and C pillars at the rear quarter.

Did this coincide with the removal of lead in paint and gas?

And, what did they replace it with at the factory level?

 

Sometime around 1970 best I can guess. That's based on my 69 Toro which, when the VT was stripped off, we found one side had lead and the other plastic. Inside the door and trunk lips and the rear fender cap finish work were lead on that side. Finally talked with a guy who was working the Euclid Toro body line in late 68 (car built 12C, explained a whole lotta weird **** on that car) who told me they were experimenting with plastic about that time and figured using it under a vinyl top would be a good place to test it.

 

I had an old timer auto body guy who use to live in my neighborhood and he told me a long time ago that he stopped using lead when bondo started coming out sometime in the mid 50's.

 

The question is about what the factory did, not body shops.

In any case, lead was used on cars without vinyl tops until the construction technique changed to the seams on the roof with rubber strips in them. Vinyl top cars just got seam sealer in the groove. My 1969 442 with vinyl top has factory seam sealer. My 69 H/O has lead. My 1980s B-body wagons have lead.

 

I worked in a GM assembly plant from 1972-1974, in Framingham Mass.


They used lead for roof and A pillar seams when I was there.


The Lead Line was the worst place to work in the factory, as it looked like a Super Fund site with tons of lead dust, fumes, and smoke.....hard to believe that GM would expose their workers to that toxic stuff.

 

As opposed to asbestos brake shoes?

 

I worked in the lansing plant,when I got there in 76 we were using lead on std tops and on the a and b pillars on the 1/2 vinyl tops. the rear seam was a plastic filler that hardened in the ovens,bondo wouldn't make it thru without popping out. if there was lead under a vinyl it could be from a couple of things,employees car,higher up car ect. if it was on one side only,it was probably someone practicing,or they didn't read the option sheet and their partner on the other side did. sometimes we would be breaking someone in on the grinding line and have the solder guys put some on so they could grind it off without worrying about it being messed up. we went to silicon bronze around early 90's. in 84 we went to a leadless solder,zinc tin and aluminum mix. harder to use but good results,still nasty stuff to breathe