painting over satin paint question

I painted my car with rustoleum Satin Black last year, shot it with my air compressor not spray cans. I don’t like the way its age and want to repaint it PPG metallic automotive paint. My question is the body work prep? The body its straight just need to re paint. Can I use a scotch bright pad to scuff up the satin paint and then primer the body? Or should I sand the body to scuff it up? Also is 2-3 coats of primer enough? Thanks for the help, learning as I go. Just my daily driver not a show car.<O</O

 

Think your going to need to get all the rustoleum off, or you may have problems with the automotive paint reacting with it. I'm sure someone else will be able to tell you why better than i can.

 

You put a very low quality paint on your car. Even IF it doesn't lift or react to what ever you put on over it, don't expect the new paint job to last long.

 

About 15 years ago I sprayed my 67 GMC with Rustolem blue just so it looked decent until I could paint the entire thing properly. A few years later I went to spray it with some better paint and didn't sand all of the Rustoleum off. I sanded the body smooth, sprayed it down with a filler primer and shot the new paint. It laid down great and looked fantastic for 3 years. The chemicla reaction between the paint ended up giving certain spots an oxidized look. In the end, I took the entire truck back down to bare metal and started over. It's the best practice when dealing with paints such as Rustoleum

 

You definitely will have to remove all the rustoleum. Any remnants of it will react with the primer first, then the topcoat.
When you get to the point where you can apply primer, use an epoxy primer. You can do body work right over epoxy so the metal is sealed already from eventual rust.

 

I couldn't say one way or the other if the new paint will react badly with the Rustoleum...probably a 50/50 chance at best...
But I can tell you this for a certainty. The Rustoleum is a non c****ized paint and the paint you want to put on top will be a catalized paint (I'm ***uming here... It's nearly impossible to buy anything that doesn't require a hardener any more and I don't think PPG sells anything other Lacquer, where available, that doesn't take a hardener.
).
The problem is that you'll have a rock hard "shell" sealing off a flexible substrate. A**** other potential problems that can occur, as the weather changes from hot to cold the substrate will expand and contract and move around on the surface by minute degrees whereas the top coat will not.
The result will ultimately be a delamination problem.

If you want a decent paint job you need to remove all the paint previously applied.

The key is to have a stable, thoroughly cured out substrate. Some vintage OEM paint jobs work just fine...enamels for example, but. If the car has ever been repainted you need to strip it to bare metal.

 

You are in the same boat I am in with my 53 HJ. I shot it hmm 7-8 years ago with JD blitz black. I have to strip it down to metal fix a few spots and repaint. Oh the person that shaved the antenna taped a plastic cap over the hole on the inside and bondo-ed over it. Haha I had to laugh at that one. The bondo has held for over 20 years but it will get a metal patch.

 

your right its very cheap paint, seemed cleaver at the time for a satin black look. Okay so`ll start sanding the paint off, whats a good grade to use 400?

 

I heard the old school bondo was awesome stuff not like todays bondo.

 

If there isn't a lot of body filler use 80 grit down to the metal and do the filler over.

 

What's under the cheap paint? If you need to strip it all, you sure don't want to be trying to do that with 400 grit.

 

I've been there before, welcome to the club...

 

I sprayed my **** hauler pickup with satin Rustoleum. It looked great for awhile.
I needed to do a bit of body repair and sprayed some primer on it and it wrinkled the rustoleum. I also wiped down a spot with lacquer thinner and it wiped the finish off.
I know when it's time to give it a new paint job the old stuff is coming off first.

 

Sand it down with 80

 

no simple or easy way to do it - just do it right this time, you'll be glad you did.

 

thanks for the advice, great work on that Model A project you posted, that Washington Blue paint where can i find that please?

 

I think 80's awefully harsh unless you're going to bare metal and evn then it seems overkill as it will mess up any bodywork you've already done. I'd sample 180 and 320 to see what cuts the best without gouging too much, probably 180, then hit it with a good filler primer and sand with 320 or 400, then if necessary reprime and block again or scotchbrite depending on how it looks. it's been my experience you can shoot most paints on top of a goos 400 sanding--especially single stage enamels.

 

80 to 120 grit is what you want to use to get it to bare metal in a hurry. Then you will have plenty of tooth for the primer to stick to, Then you can touch up any body work and start sanding with 400, touch up primer spots and then you can spray your sealer. That's how I've done it in the past

 

Isn't Rustoleum enamel based...???

If it is, start with lacquer thinner on rags and wipe...wear several pairs of rubber gloves cuz that black is going to go everywhere...!!!

Once the majority of it is off, then start sanding...

R-

 

That's what I,d do.

 

There you go! Use laquer thinner to get as much as you can off, sand wet with 320 or 360 and put a catalyzed sealer over it. PPG DP 40-90 works well.

 

yes I dont want to go to bare metal just remove the satin paint, the body work is good but i will block it again, primer it. smooth it out than shot the primer again. the useally stuff before shinny paint. the holes and trim are shaved so i dont want to mess with that body work, thanks for the advice.

 

im going to try that, never would of thought of that, thanks guys, im no expert. just at beer.