Question for Keith Seymore on GM Paint
 

Keith or anybody else that might know:

We all know that the older models of Chevrolet (GM) like Corvettes and
Camaro's had Acrylic Lacquer and later changed to Enamel. I do not know
what year this happened. My question: When did the Chevrolet P/U's change
over to enamel? Did all plants that made the trucks make the change all
at one time or where there staggered in?? Thanks in advance-Larry:chevy:

Re: Question for Keith Seymore on GM Paint
 

I don't recall when the change from laquer to enamel happened (probably could find out with a little research).

I can say that the changes were rolled out on a plant by plant basis, as they were ready. Too much waste to change over 7 plants all at the same instant.

The changes were rolled out even within the same plant. In 1987 Line1 (pickups) at Flint Assembly was still high solid enamel but Line 2 (Blazer and Suburban) had already converted to base coat/clear coat. A similar transition occured earlier when Line 1 was still spray primer but Line 2 had installed the ELPO tanks.

K

Re: Question for Keith Seymore on GM Paint
 

Keith: Very interesting; so I presume that at one time the same model truck made at different plants had different type paint; correct? When you get a chance please find the aprox. date of changeover to enamel. Just off hand you would think it happened in the 80's rather than the late 70's? Larry:chevy:

Re: Question for Keith Seymore on GM Paint
 

Yep. Same model truck made at the same plant with different type paint, too.

Will do. There may have been some EPA/emissions mandates that helped facilitate that change.

K

Re: Question for Keith Seymore on GM Paint
 

Any easy way to tell if its enamel or lacquer?
Posted via Mobile Device

Re: Question for Keith Seymore on GM Paint
 

Find a spot no one will see like under a door panel and take a rag with a little bit lacquer thinner rub it on the paint.If its lacquer some of it will dissolve and show the paint color on the rag.If no color then its got a clear coat and it might wrinkle it so do it somewhere no one will see it.

Re: Question for Keith Seymore on GM Paint
 

Have painted tons of squares, none were ever painted in lacquer paint. Even 67-72 were all enamel, before that I don't know.

Re: Question for Keith Seymore on GM Paint
 

After a bit more research -

It appears that lacquer was used for cars because it was more "forgiving", would "reflow" when baked, giving a nice finish without requiring highly skilled painters.

The transition to Dupont's new acrylic lacquer at GM started around 1956; Soon after, it had completely supplanted the older lacquer formulations. This would be the acrylic lacquer that was what GM identified as "Magic Mirror" on the Data Plates for a time. All of my mid 60's Pontiacs were acrylic lacquer originally.

There may have been some EPA/CARB motivation in the switch, but it may have been as much to do with economics and paint advances (probably OSHA too). At the factory level, they may have been trying to avoid health concerns for the guys in the paint booth.

To add to the confusion CARB (the California Air Resources Board) forced GM away from the solvent based lacquers at the Calif Plants. Doesn't indicate the year but suggests prior to the 3rd gen 'bird (that was '82).

One source states that Ford and Chrysler switched to enamels in the late '60s in response to Gov't air emissions rules while GM switched from solution based lacquers to high solids dispersion type lacquers.

However, based on Ont Guy's response it looks like the truck platforms may have been on a different timetable than the passenger car plants. My recollection is that all of the pickups at Flint were high solids enamel by the time I started in 1979 (I don't recall any big news about a changeover at that time).

K

Re: Question for Keith Seymore on GM Paint
 

This is from a 1963 Chevy data book