TR4/4A Original TR4A paint: enamel or lacquer?

[Sarastro]

I'm stripping original paint from my TR4A, and I was wondering if it is lacquer or enamel. I've found a couple of old threads saying that it is enamel, but they are a little uncertain. The first thread says it was enamel, but called "nitrocellulose lacquer." I find that confusing, as the latter is a specific type of lacquer, and it's hard to write it off to differences in British and US terminology. The second thread also says enamel, but is really referring to later, post-1970 cars.

https://www.britishcarforum.com/bcf/showthread.php?79681-Original-TR4A-Paint&highlight=paint

https://www.britishcarforum.com/bcf/showthread.php?46496-Paint-type!&highlight=paint

I'm concerned about this, because it's inevitable that there will be small areas of paint that are inaccessible to stripping tools or even abrasive blasting. I hope to scuff these and epoxy-prime over them, which probably is fine if they are enamel, but if they are lacquer, I'm not sure that's OK.

 

[Got_All_4]

My TR3 was lacquer. If you take a rag with a little lacquer thinner on it and rub it it will clean the paint up and soften the paint. If it's cured enamel it won't touch it.

 

[Andrew Mace]

When I got my '67 Sports 1200 in 2012, the previous owner had managed to cover the entire outside with flat black paint. As long as I live, I'll never know why; neither did the family of the late owner know why, except that their dad / granddad had almost a fetish about flat black spray paint!

Anyway, several gallons of cheap lacquer thinner or acetone (depending on what was on the store shelf at any point) removed it without harm to any of the original or retouched paint underneath. That pretty much confirmed my belief in enamel from the factory!

 

[TomMull]

My guess is that the original paint would have been an alkyd enamel but I would not worry what it was, particularly if most of it will be removed. I'd use an epoxy primer over the bare metal as well as over the dregs of remaining paint no matter what kind of paint it was. Maybe not a concourse approach of course but has so far worked for me. (The lacquer thinner test mentioned above is a good one and you could also try rubbing the original paint with the reducer for the primer and/or the paint you intend to use.)
Tom

 

[Sarastro]

It gets curiouser and curiouser.

I tried (again) testing the outer surface with lacquer thinner. Initially, it did nothing, but after some effort, it softened the paint enough for me to scratch it with a fingernail. I'm not sure what that means.

Then, I sanded the paint a bit to see if it made any difference. It didn't change the results of the lacquer-thinner test, but I discovered something new. In the wheel wells, engine compartment, trunk, and the area behind the dash, I had found only red-lead primer and a finish coat, which made me conclude that I was dealing with original paint. But on the outside, there was an extra layer of paint and primer, so it seems clear that the car has been repainted once already in the original color.

I think Tom's suggestion makes a lot of sense--I'll strip everything I can, and not worry about small areas that I can't strip. They mostly will be in areas like the insides of the tail-light enclosures and similar places, which probably won't matter. There also is nothing in the epoxy-primer instruction sheet warning against use over lacquer. So I think it should work.

I'm not going for a concours restoration, but I really don't want paint problems, either. The goal is to end up with a good-looking, mechanically sound car.

Thanks for your thoughts!