I'm not asking for any miracle, pal. Just trying to understand what's going on, since the touch up paint site leads you to believe you can just spray their paint over any existing paint. I know PPG 2K primer and sealer goes over existing paint just fine, we use it at my job. (Why don't I just paint it at my job? well there's a few reasons, but I rather not get into it). I had no idea lacquer paint was like this.

Yes, I will be stripping the entire decklid. But for future repairs, it would be nice to not have to strip everything to bare metal.

What you are experiencing is exactly the reason why I don't recommend rattle can products. Unless they are specially mixed 2k (2 component) at your jobber specifically for your application they are incompatible with today's automotive paints.
Using products that attack each other is never going to produce acceptable results.

Had you used the PPG automotive products, and followed the proper application procedure touched on by NTFS, you would not have had to make this post.

Trying to make the lacquer based product "work" in an application where it does not belong is going against the grain of reason. Lacquer and enamel paints are LONG out dated products when it comes to cars and trucks.

CarLover wrote:Yeah it is. Acrylic laquer. ? Whats wrong with using it? Isnt there a way to make it work? Didnt they used to use laquer back in the day?

They don't make things like they use to. Thats a common statement, but in most cases we are all better off because of it. But in other cases such as lacquer paint, painters are only better off---if they don't use it.

So in addition to the problems already mentioned about your procedure, the formulation for lacquer was changed in the US since it was so widely used back in the day.

I see what you all mean.. At work we laugh at people who got their bumpers painted in a parking lot and the paint is peeling. I guess it's my turn to laugh at myself now. But I will never spray 2K anywhere near where I live. I would only spray it in a professional booth with a supplied fresh air system. I just wanted to have a little paint project to make my car look better. Someday I will meet a trustworthy person with a shop where I can leave my car there and slowly do a complete restoration. Or find a quality restoration shop that I can trust.

Now my only remaining question is.. How does SEM make such good lacquer rattle can products? I called and asked them and they said theirs are lacquer based too. I've sprayed different SEM rattle cans over existing paint (only sanded w/400 grit) and it laid down fine. No peeling or lifting at all, it looks great. And the SEM products don't even need primer.

This is only speculation since I am not a chemist or have a lab setup, but I believe the SEM products are just higher quality than most rattle can products. Most of the rattle can paints you buy in the store have over 80% solvents. If they are using recycled solvents (as many are), you have no real indication what is actually in the paint formula. It could have any number of chemicals that can attack an existing finish.

You may also have just been lucky in the past. I have used rattle can lacquer products on some small projects without issue. Other times it has made a huge mess of a project. I have also had some horrible reactions with epoxy and urethane primers sprayed over lacquer based fillers (3M Acrylic Green), that did exactly what you show with the crazing/cracking.

chevman wrote:

CarLover wrote:Yeah it is. Acrylic laquer. ? Whats wrong with using it? Isnt there a way to make it work? Didnt they used to use laquer back in the day?

They don't make things like they use to. Thats a common statement, but in most cases we are all better off because of it. But in other cases such as lacquer paint, painters are only better off---if they don't use it.

Can you expand on why you think that painters are better off for not using it?

So in addition to the problems already mentioned about your procedure, the formulation for lacquer was changed in the US since it was so widely used back in the day.

So what's changed and why would they change the formulation for it only in the US?

The main thing that I know is they took the lead out.