I know you guys are sick of answering questions about paint, but i did alot of searching and i'm a little lost. For starters, i know nothing about paint, so please use specific brand names and simple terms. I want to repaint my car, i've got a friend thats good with a paint gun, but i've gotta do all the prep. Here are my questions...

I guess i should also mention that my car is getting a different color put on, and that it's already got two coats of paint on it (factory and a repaint over the top)

1. I've read that i should just scuff the paint thats on it, that i should sand down to primer, and that i should take it to metal...which should i believe?

2. if the sand the paint thats on it method works, how well does that adhere and do i still have to prime?

3. How are the plastic parts supposed to be prepped? do i take them to the plastic then spray primer, do i just sand to primer, or do i sand the paint thats already on them and then paint?

4. I've read that on the plastic and fiberglass parts i absolutely have to use a flex agent, and on other posts that as long as i use a certain kind of paint, no flex agent is needed, which is true?

5. I plan to fill in the emblems on the rockers, but i want to paint under them too, instead of leaving it in primer or the old paint color, how do i do that? i'm under the impression that bondo needs to be applied straight to the plastic, so i'd have to paint the car, then attach the ground effect, then bondo it, then mask off the car...i think...right?

6. do i have to use a special kind of bondo for the rocker ground effects?

7. how many coats of clear? i've heard lots is good, and i've heard lots can also make it look very bad

sorry i'm so confused, i tried to figure it out on my own...but it just made it worse...thanks in advance

 

As to scuff-sanding or primering or bare metal-

1. If the paint on the car has withstood the "test of time" for adherability, you just need to scuff-sand. By withstanding the test of time, I mean that there should be no: Nicks, chips, cracks, spiderwebbing, or checking. If there's any of those conditions, you must take that area down to bare metal. Why? If you spray over nicks/chips/cracks/spiderwebbing/etc, it'll show through the new paint.

You have to consider your paint thickness, too. Too thick isn't good, and the paint could crack/chip. So it's your call on whether to strip the paint off. I'd say to take one section down to bare just to see how thick the topmost layer of paint is.

Scuff-sand with 320 grit paper on a dual-action air sander. If you don't have a d/a sander or air compressor, buy a cheap 8" random-orbital buffer (not high speed). Attach 320 grit paper to the buffer, and "buff" your paint with the 320 grit. When you're properly finished, the paint will look like a badly faded paint job.

Remember that you MUST, absolutely positively MUST, use a cleaner on the paint prior to ANY sanding!! If you just wash the car and then sand it, you'll be embedding contaminates into your paint, and they'll eventually show through (if not immediately)! Washing the car isn't enough; using bug & tar remover on the lower panels near the tires isn't enough, either. You need to clean ALL the paint so it's free of bugs/tar/bird crap/road slime/old wax/acid rain/beer/soda/etc.

You can use lacquer thinner on a rag. You could buy cans of "paint prep" at local auto parts stores. (I use Total Prep by MarHyde, the same company that makes Bondo, $8 a can at Pep Boys.) But use something! And hose the paint down after all contaminates are removed.

2. It'll adhere well with 320. Some people say to go to 400, but I haven't had success with that. You don't need to spray primer unless you hit bare metal while you scuff-sand. Now, if you're using the random orbital or a d/a sander, and the original paint flecks right off and you hit bare metal, well, guess what, bad news. The original paint hasn't withstood the test of time for adherability, and you need to go down to bare metal.

Actually- wait. You're changing the color? You might want to spray a "primer/sealer". The key word in that is "sealer". This will prevent (A) the old paint from bleeding into the new paint, and (B) the new paint having a chemical reaction that would sink into the old paint.

3. Plastic parts- same cleaning and scuff-sanding procedure. The bumpers usually take parking-lot damage, and the paint cracks- in which case, you'd have to d/a down to bare urethane, and use primer.

4. I've seen cars with flex agent added to bumpers (think of factory paint!) in which the paint still cracks. If you're going to kill yourself over getting flex additive, don't even bother. If it's free, go for it. When I shot my bumpers, I bought flex primer from Pep Boys... two stages... first can was "flexible bumper adhesion promoter", then "flexible bumper primer". Do not use a sanding disk on a power drill to sand your bumpers! You'll groove the hell out of the urethane.

Can't help with the others, sorry. Check out http://www.eastwoodcompany.com for bodywork tools to help you out. In particular, for removing paint, I just picked up the scotchbrite pad and disc for my 4 1/2 inch grinder. Seems to work a lot faster then my d/a sander. I bought my grinder from http://www.harborfreight.com for $20. See the disc I'm talking about at http://www.eastwoodcompany.com/itemdy00.asp?T1=31094 and the backing pad here: http://www.eastwoodcompany.com/itemd...ep_Key1=BodFen Basically go to the main eastwoodcompany.com website and go under the "main" "Body and fender- Prep" section (not it's subsections) and you'll get some ideas.

A good book on bodywork is the one sold thru summitracing.com ... I forget the name, sorry... it's got a yellow car on the front.

One warning spot: The roof. Look at the spot where the b-pillar meets the roof. That area is filled with lead from GM. Don't think it's a funny gray Bondo, don't try to sand it away. Be careful removing paint over this area. That's what's great about a d/a sander; it doesn't dig deep. Always start the d/a sander (or orbital buffer) with the sanding disc pressed against the panel; that way you won't gouge the paint by putting a fast-spinning disc against the panel.

Good luck... as I always say, the key is in the prep. Any idiot can slap up Bondo and paint onto a car- and the results look like an idiot did the work.

 

is primer/sealer and self-etching primer the same thing? is there a particular kind i should look for or steering clear of? i'm assuming the spray can stuff is out of the question. If i do have to take an area down to bare metal, the primer/sealer all i need right? do i do multiple coats or not?

see, i messed up my fender and got a used replacement, the replacement has a few areas of surface rust, the rest of the car has two layers of paint (i sanded down the messed up fender and my colors were brown, grey, brown, grey, black. The greys were primer, the brown was the paint, and i assume the black is etch? the paint is pretty thick because i was using 220 and it took about 45 minutes (i did take my time) to get a 10" circle of bare metal on the messed up fender, which i think is representative of the whole car's paint job.

the clearcoat is peeling off all around, but the paint itself is stuck pretty good...so should i sand until i get to primer just to be sure?


thanks a ton man, i can't even begin to tell you how helpful you've been

 

With several coats of paint on the car I would sand it down to the FACTORY primer and go from there. Reprime the car (flex additive in the primer for plastics) color sand, then pigment (no flex additive for pigment if doing base coat/ clear coat), then clear coat with flex additive for the plastic parts.
Make darn sure if doing a base coat / clear coat job that you get the clear coat on the pigment within the recomended time (16 hours) the sooner it is applied the better.

 

color sand? is that when you mist the primer with a contrasting spray paint and sand it off?

 

Tom has given some great advice here and he seems to know quite a bit about bodywork. However, I would disagree with one thing. I would not paint right over your current paint job having just scuffed the finish. Do you know exactly what brand and type of paint were used on the last job?? Probably not.. And if not, then you will be guessing about the compatibility of your new finish and the old and I would hate to see you end up with a paint job that lifts or never adheres correctly.

The prep work and sanding will determine how long your paint will last, and more importantly if it will ever even adhere right off the bat.

If you are going with a complete color change, its gonna be tough. What about your engine bay? What about the doorjamb areas? All these are considerations you want to have in mind if you dont want to end up with cheesy looking finish.

I would also reccommend sanding the plastic parts down to primer or to the bare urethane if possible. You will be the most satisfied with the results in the end if you take the time now to do that part. Also, you should use an adhesion promotor on the urethane parts when you primer them.

If you plan on "shaving" the emblem areas on the ground f/x, do not use bondo. There is special epoxy or filler used for flexible plastics that will serve the purpose much better. Try 3m's 5830 flexible plastics repair. You can see in my website what I did with it for my plastic parts, the results were great.

And last, I would highly reccomend you check out this website:
www.autobodystore.com

The amount of information there on painting and bodywork is staggering, and you will learn TONS there. Check it out.

Any other questions, feel free to message me.

 

when i pulled the engine, i stripped the engine bay to bare metal and painted it up with por-15, it needs to be redone, but it's not a high priority. I do alot of engine tinkering, the engine bay will just get scratched up again, it's not a show car, just want it to look good goin down the road, door jambs i was planning on doing with the rest of the car, masking off the interior, cuz the doors and fenders will probably be done seperate from the rest of the car.

 

OK, let me throw my 2¢ in here:

If you are going to paint over the existing finish, you do have to worry about paint compatiblity problems. If you don't want to strip it, you can scuff and paint, but you will have to start with a SEALER.

As far as scuffing, 320 grit on a DA will remove paint fast! Hand sanding with 320 has always worked good for me.

Like mentioned before, if there are chips, cracks or signs of paint lifting, its best to strip it down. Prep work is the most important part of a paint job, and the "new" paint will only be as good as what its covering. If the old paint is starting to lift, the new paint will lift right off with it.

 

i just got back from talking to the guys at carquest (only store i could find that mixed paint) and they said 2qts of clear, a gallon of base, and "Bull Dog" would cost me around $225 and that it'd do my whole car including jams and such. I know you get what you pay for, but i dunno what paint costs, so am i getting decent stuff based on that price?

What's the story on this Bull Dog stuff? The guy said to just spray it on my bumper covers and paint, instead of using primer and paint mixed with a flex agent...that sounds weird to me, but i wanna know what you guys have to say about it.

If i do take the car to bare, what primer do you recommend? it needs to be a sealer-primer/self-etching primer (i hear they're the same thing) right? anybody recommend a brand?

Lastly, the color i'm looking at is Dark Shadow Grey...it's an 02 Mustang color...is it wrong to paint my car a stang color?

 

bulldog is a type of flex agent we used it on street bikes

 

good stuff then? just spray it on and paint over the top?

 

yup