acrylic Lacquer?

M

MKH

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I have this 1975 corvette. It’s still got the original silver metallic acrylic Lacquer paint that it left the factory with. The paint is very faded with no shine but still very solid with no flaking or crazing just some small chips.((except for the t tops). I tried wet sanding and buffing a small place on the hood. It’s shiny in that spot but looks very blotchy now. So my plans are to repaint it over the winter. My question to the forum is would it be ok to epoxy prime over the existing acrylic lacquer or does it have to be stripped to bare fiberglass? Thanks
Mike
 

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It's sort of okay in a jamb, but not on the exterior. Do yourself a big favor and remove that old lacquer. Epoxy turns it into liquid that bleeds into the epoxy, it's quite a sight and can't be good, I've seen this personally on cowl side panels on old GM vehicles. I got away with it on unseen areas, but would never risk it on an exterior, ever.
 
Lacquer never stops moving around, combine that with a fiberglass body and you’re asking for trouble by introducing a new product. Remove it all and start fresh with epoxy.
 
Couple years ago I asked Barry this exact question. Can I put epoxy over lacquer? He said NO. Not unless you want to have all kinds of problems. He then explained it to me chemically why it was a no no. I then understood. So that is the answer I got from the man himself. Be wise and take it down to bare glass. Lacquer dries but never cures.
 
Ok sounds like epoxy is out. What about SPI 2k primer over the existing acrylic lacquer? Car only has 56000 original miles. Door jambs and inner door paint are in very nice condition, so I was just going to spray the outside.
 
MKH said:
Ok sounds like epoxy is out. What about SPI 2k primer over the existing acrylic lacquer? Car only has 56000 original miles. Door jambs and inner door paint are in very nice condition, so I was just going to spray the outside.
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From what Barry explained to me the new catalysed primers are completely non compatible with the lacquer paint. It may look ok for a while but it would eventually fail and he gave me several instances where that had happened. One of them actually was a car that still had the original lacquer paint from the factory. He went into great detail in explaining why they were not compatible.When he was finished explaining I completely understood why.
 
MKH said:
Ok sounds like epoxy is out. What about SPI 2k primer over the existing acrylic lacquer? Car only has 56000 original miles. Door jambs and inner door paint are in very nice condition, so I was just going to spray the outside.
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The problem isn't SPI epoxy or any other modern paint, the problem is the old lacquer. If you don't want to strip it maybe you could use Duplicolor lacquer primer and paint, at least that would be sticking with the same technology.

Just kidding, strip that old paint or go home.
 
MKH said:
Ok sounds like epoxy is out. What about SPI 2k primer over the existing acrylic lacquer? Car only has 56000 original miles. Door jambs and inner door paint are in very nice condition, so I was just going to spray the outside.
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Even worse than epoxy over lacquer. It will cook up. Lacquer is very solvent sensitive. Lacquer will liquify when it is penetratrd by solvent, even more lacquer will do that sometimes. That is what is meant when you see someone say it moves around. Either that or it cooks up. The few lacquer jobs I did waaaay back in the early 90's, GM stuff, Caprices mainly, it was always an adventure trying to blend a repair and not have the lacquer you were spraying cook up the existing lacquer. Or melt it.

If I was repainting your Vette, I would strip the exterior. It won't take long, probably could do it in a day using a heat gun and razor blade. Strip the exterior, back tape the jambs and pray you don't have an issue at the transition point there. It's very possible you will. Keep in mind also depending on your taping skill the transition area in the jamb will show and you can't really buff there with two dissimilar materials.
 
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Thanks everyone for the replies. I really do appreciate them. I guess it’s strip the entire car or just live with it the way it is.
Mike
 
For the amount of time it would take to actually strip the car down I'd say that worth it rather than putting a new finish on top only to see things ghost back down the road. I have always stripped lacquer paint off. Personally its just not worth the risk IMO.
 
The paint is not thick enough to cut and buff, but what do you guys think about trying just a light buffer polishing, since he only wants more shine?
 
if you warm the paint it will peel in long strips. if you dont heat it then it will fly off in chips which get everywhere like sand. eye hazard forever because you will never get them all blown out.
if it's solid you can hand wax it like in the 60's. NOTHING is compatible with it .
 
The probability of problems are near 100%. When I started in the 90's they called it cracker lacquer. Base clear eventually cracks over it.

If you decide to buff it, do not get it hot or it will smear and ruin it.
 
MJM said:
I know SPI has said not to use their epoxy over lacquer. It's stated in the commonly asked questions. However, it appears there are other epoxies that can be used over lacquer.

Here's a video explaining the use of this particular epoxy over lacquer to lock it down before spraying polyester.


Just another option for the OP if he doesn't want to strip the existing paint. How the epoxy is applied is the key to prevent the lacquer from lifting.
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Nooooo! not unless you are unloading the car quick. this is not anything new, the cracking will work its way back up to the surface within a year or two depending how much sun the vehicle sees.
 
BrianK said:
Nooooo! not unless you are unloading the car quick. this is not anything new, the cracking will work its way back up to the surface within a year or two depending how much sun the vehicle sees.
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And that's why 90% of these youtube videos are shit.
And he's holding up a can of slick sand in the vid screenshot. If he's calling that epoxy........Lord.
 
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