i have a 85 firebird that i am getting painted. the original color of the car is silver but i put the T/A GFX on wich are red and changed the doors also(they are red to) becaus they are 4 years newer. i sanded the hood down alot almost stripped with a 320 grit then very lightly with an 800, the rest of the car i sanded lightley with an 800 grit, this was all done with wet sanding also.i am taking my car to get painted at earl schieb(just like macco for those who don't know).the color i want to get it is candy apple metallic red.i want to do as much prep work as possible (because they don't do prep work for anything) so they can just focus on the painting the car. my question is have i sanded the car down enough, if not how much more should i sand it, what grit to use and in what order do i use it in, its no 5k paint jobs more like 500$ so i need some info. thankyou.

 

Chances are the 800 grit is too smooth. Call the shop thats going to paint it and ask them what they want you to sand with. Usually they will want you to finish with 300-400 grit so the paint will have something to stick to.

As far as how far you need to sand, providing the existing paint is in good shape, you only need to sand untill the car is smooth & straight.

Take a look at the link in my sig for my current paint project.

 

What if it's been re-painted, but it's still in good shape?

 

Just when you think your done, do it 12 more times! And I agree, 800 is probably to fine until the last couple of times.

 

Are u primming the car? If so u can sand in down with 180 or 220. If u are not primming and are going to use a sealer before the base 400 wet is good. But like mark said call the shop. See how they would want it. Than that way they can not say u did it wrong. Trying to get more money out of u.