Technical A Question About Paint.

OK, I have a question about painting a car. My question concerns stripping the old paint. How much of the old paint has to come off? I have been around custom cars off and on over the years. My understanding with painting a car is that if the base paint is solid then you can paint over it. I have some rusty spots that I have to sand and treat but there are a number of places where the paint is very hard and durable. Feedback is appreciated.

Edit*
Since I’m painting the underbody and frame are there any suggestions about what to use? I’m wanting an epoxy paint for each and am thinking about Raptor or Lizard skin on the underbody. Thoughts? Things to avoid?

 

If your talking about 40 year old OEM paint remove it or regret it it's the same with all repaints, just remove them if you want a quality paint job.

 

Paint is 99% preparation. Whatever is under it dictates how it will come out and endure. Paint is not for hiding bad body work, it will just color it. Strip it to the metal and properly treat and prime it if you want it to look decent.
BTW, you ought to edit out of your post what the vehicle actually is, some people on here will report it as being off topic.

 

If compatible, beneath your next paint choice, leave the door jamb paint regions, just de-wax/solvent & lightly sand them for bite.
Leave a 1" border of orig. color, outside, around the jambs, sand it back when you repair & prep a panel. The light full sanding of clean jamb regions will take color and dep. upon the new color, not broadcast a change. Spray jambs, allow tack-up, touch test, close openings, then mix & hit top surfaces. (Chime in guys, theHighlander?)

 

Thanks for the advice. I kind of feel out of place with my vehicle choice.

 

Those were the answers I expected even though I was hoping I was wrong. What was supposed to be a quick rust repair and re-spray has turned into almost an entire tear down. It is safe to say that this project is getting bigger by the day. I read somewhere, probably on here, but any restoration project should have the expectation of doubling the budget and doubling the length of time.

Pitman, that’s good advice. Unfortunately, the only original paint is underneath the dash and the firewall and underbody. Somewhere in its previous life someone got the bright idea to repaint it a color from the 1960s. It would be awesome except it looks like someone used an entire gallon of PPG paint with no reducers or reasonable prep. There are sections where the respray is either peeling, bubbling, or flaking.

 

Hoping theHighlander, or anothet Pro will advise, glad you inquired. Prep, it is all about! I corrected my above post to be clearer.

 

In this case, I would say the whole thing needs to be stripped. There are definitely times where old paint can be painted over, but if the current paint is failing, you're asking for trouble painting over it, even if there are large areas that still seem good.

Also, your rust areas need to be sandblasted clean, "sanded and treated" is not good prep for rusty spots.

 

And to respray over the peeling paint will only make it worse, the solvent in the new paint will make the old paint fail quicker.

 

2 paint jobs? Strip it all off. The only exception is the factory primer. Leave it if it's good.

 

I have been cutting out any rusted parts and replacing them with new steel. Anything not replaced has been stripped as best I can. I’ve been using acid or a rust converter like Ospho (as recommended by another HAMB user). I’m pretty limited with tools and my budget so I’m trying to do the best I can with what I have.

 

Beware of project creep. You ask for opinions and you're gonna get them. I'm just saying, beware of project creep.

 

Yeah. The original paint is pretty solid in some areas and garbage in others. A previous owner painted the exterior and used a garbage bed liner material on the fender flares and roof. It’ll all have to come off.
The point of my OP was that some sections have a really hard factory paint and primer that is tough to sand through. Regardless, it looks like many more days of sanding before I can get to the fun stuff.

 

I welcome opinions. I think I’m WAY past the point of no return. The only thing still attached is the dash and the glass.

 

Sounds like project creep has already happened....

 

Yeah. It was supposed to be replacing of the floor pans and some minor repairs but while I'm there...

 

You know, this is how fixing a dripping faucet turns into a full bathroom remodel! Hang in there man, these guys can help you get it done.

 

Have you considered spray on paint stripper? It works well.

 

I thought it would be pretty messy but I am open to suggestions if you know of any products that would work.

 

You are right, though...
I have read that if the paint has been on there for a long time, and it's sound and compatible with the new products, there should be no worries.

Yet it's obvious that if you want to be sure, take it off and start with absolutely clean metal.

You've taken the car almost completely apart. If I had gone that far already, I think I'd try to remove every bit. Not much more money involved, just more work.

Good luck.

 

I used Aircraft Stripper. (Google it).

Nasty and messy but IMO better than sanding......don't ignore the precautions.

There are times you can paint over old paint but IMO in your case it's going to look bad and you'll end up with places you can tell were repaired with problems down the road.

 

I remember when the Earl Scheib and other auto painters painted over the original paint.
"We'll paint any car for $29.95"

 

HA! I had a buddy years ago that did the Maaco paint job. He did all of the prep work and the paint still looked like crap when it was done.

 

$10.00 free metal work

 

Are you painting a taxi or a dump truck or a circle track car that’s really a bumper car, Or making a work van looks like an ice cream truck? Maybe try to get another year out of it before the neighbors have a fit? Going to try and sell it tomorrow?
Then paint over the old stuff

 

Prep is about 98% of how a finished paint job will turn out and the part most people do poorly and then think it is the "crappy" paint or painters fault.

 

A friend had them paint his Camaro. Painted everything except the windows. Window trim, emblems, everything.

 

Nope. This may not be my forever vehicle but it is one that I want to keep for a long time. I plan to drive it and use it mostly for its intended purpose. Eventually, it will be a tow rig for my Jeep Wrangler.

 

He removed everything and masked off everything that he could except for the front windshield. He did that when he got there. The paint just had runs and orange peel all over it.

“I’m not a painter but 500 bucks is 500 bucks.“
- Maaco

 

Paint strippers: That's what I mostly used when I originally stripped my entire car down to bare metal. The aircraft strippers use to work real good. I don't think you'll have as much luck with the strippers sold in Lowe's and Home Depot anymore since the EPA seems to have had a major impact on how effective that stuff is. That was the experience I had last year when I was stripping old enamel off my kitchen cabinets. 4 out 5 didn't work worth a damn. None of the new ones worked as good as an old can I had.
Most strippers recommend flushing with water. That's near impossible to do on a car inside a home garage, so next best thing, imho, is keeping the stripper an inch or two away from seams and edges, just doing the bulk of areas within each panel. Definetly want a gel stripper. I have no idea what paint supply stores sell for it, but it's got to be better than the big box stores??