I have an 89 Camaro with a gun metal grey paint job on it. I want to give it a new paint job but what Sandpaper grit is recommended for removing the paint before the primer and what grit should I use after the primer ? I've done some research but everyone says something different so I decided to post on here to see what you guys have used for on a similar car . Thanks

 

Are you painting over paint? A lot of the cars I imported from the US had that done and it's nothing but trouble. Take it down to bare metal using either stripper or a abrasive paint removal disc. Sand down with 180 grit so the metal is smooth and shoot the whole thing in epoxy. Then block down, fill spots, block and prime and paint.

 

I agree with Twin_Turbo on this one. The clear and base on our cars was sometimes crap and I would hate for you to spend time and money on new paint just to have it not adhere.

I would start out with a 60-80 to cut the paint off 180 to smooth the metal. Prime and body work using increasing grits (220, 320, 400 ,etc.)

 

If the paint on the car isn't in bad shape (no delamination, peeling, spider web cracks in the paint or rust) you can sand the original paint. However these cars may have multiple paint jobs which you may not know about until you try and sand to the bare metal/urethane/plastic. If it has more than one repaint you will need to remove all the paint.

As far as what grits to use, you absolutely must consult the tech sheet of the paint you are going to use. Every paint product has differences. It could be a disaster for you if you stopped sanding at 180 if the primers tech sheet said sand to 320 if applying over existing paint. On the flip side 180 could be to fine a scratch for metal and it might not adhere well enough. There is a general rule of thumb that is said about what you're painting over, the harder it is the lower the grit and the softer it is the higher the grit.

 

If you just sand the paint chances are it will lift especially where you sanded through, did repairs and what not. Nothing more discouraging than a lot of time and monet in a paint job that went bad because of poor prep.

 

If you were to sand the existing paint and then just spray the color coat without any type of primer than yes, you may have lifting issues. You can have lifting issues and other issues if you prep incorrectly or not at all. However, if you use a reputable paint manufacturer's system like DuPont, PPG or house of color and follow their directions explicitly you will not have troubles down the road. It even says in the tech sheets you can use pre existing paint in good shape, provided it isn't layers thick. I repainted my 92 over the factory finish ten years ago with DuPont and their is not a single problem. It even was parked outside for five of those years, summers and winters in Illinois.

 

Tibo, this is what I was planning on doing. I will have some spots bare metal but the majority will be over the original paint. If I prep it and shoot it with a 2K primer will I be Okay? What grit would you recommend for the final sand before primer?

 

You can apply the 2k primer directly over existing paint- you just need to look at the primers tech sheet for proper surface prep as to what grit to sand up to before spraying the primer. If you break through the existing paint to bare metal while sanding the existing paint or while sanding primer you'll need to spot spray with epoxy primer. As far as what grit to sand up to before spraying color, again you'll have to check the color coats tech sheet. Most will say solid colors in a light shade only need 400 grit but pearls, metallics or dark colors will usually ask for 600 but I've heard some of the pro custom guys in magazines and on YouTube and car shows say 800 for anything dark with flake.

In at least one spot on the front and rear bumpers and the hood I would sand to nothing to find out how many times if at all it was repainted. My front bumper was repainted four times, doors at least twice, fenders at least once. I had to take those down. I'll post a picture and you can count the layers as a demonstration...

 

Having been in the business for 35 years, I will suggest, especially if you are new at this, to completely strip the car with a quality paint stripper. So many of these cars are 30+/- years on the road with multiple paint jobs or touch ups and have serious deterioration.
You will give yourself the best chance at a quality paint job that will last a long time by going this route. The other posters are correct in that you can sand and paint over previous paints and there are good products for that. However, so many times I have seen a job that didn't have enough of or the correct prep work in many areas. Starting from bare metal everywhere will let you proceed with less hiccups! Good luck either way you choose and be sure to post some pics!

 

Having been in the business for 35 years, I will suggest, especially if you are new at this, to completely strip the car with a quality paint stripper. So many of these cars are 30+/- years on the road with multiple paint jobs or touch ups and have serious deterioration.
You will give yourself the best chance at a quality paint job that will last a long time by going this route. The other posters are correct in that you can sand and paint over previous paints and there are good products for that. However, so many times I have seen a job that didn't have enough of or the correct prep work in many areas. Starting from bare metal everywhere will let you proceed with less hiccups! Good luck either way you choose and be sure to post some pics!