ok, lets say i have a car with a straight body, no rust, where the paint is just pretty faded. do i need to bring it down to the bare metal or do i just sand it to take the gloss off the paint? and then from there, if the original paint just needs to be scuffed, do i have to prime the whole car or can i just shoot over the old paint seeing as though the original primer is still on the car? and i have tried researching but the more i read the more confused i get. can any1 offer any insight?

 

I am new to this myself and been reading stuff here and there. From what I can tell, here goes [anyone, please correct me if I say anything that don't make sense] ....

you definitely have to sand before spraying. How much you sand is completely up to you. Usually if the existing paint job is of good quality, then just scuffing the top layer is enough. If car has been already repainted once (especially if you don't know by whom), then taking it down to bare metal would be more common. Some people choose to sand down to primer because belief is that original OEM primer if it is still solid offers very good protection.

If it were me, I'd sand to bare metal because then you'd also uncover all surprises that may have been hidden their by previous owners.


As far as you applying primer, you always have to do it no matter how much you sand. The reason you use the primer is to provide adhesion for the color layer. You have to prime and then you have to spray color within recoat window of the primer (usually few days). If you miss that window, you have to sand and spray primer again before color.

Another reason you want to prime is because usually you can't predict how new paint will react with old paint. The two are usually different compounds. Using a sealer coat of epoxy primer, ensures that the new base coat will not have any conflicts.

 

you can get away with just a good sanding. I would not advice going to metal if you don't have to. Depending on how you would do it, there would be a good chance that you could warp some panels besides this route will cost you alot more money. However if you want this to be a show car and not just a driver then go ahead and go to metal.

If you go with just a good sanding, make shure you sand and use filler on any chips or real deep scratches in the existing paint. Use a block to sand and not your hand. Also it is very important to pick up some wax remover. You may think there was no wax left on the car but there is always some.

As far as primer: If your going to stay the same color, you can go without it. If you want to do a drastic color change then primer will help it cover better.

Good luck and have fun sanding

 

thanks for the info guys, im sure i will have many more questions.