When to use primer
 

I have a straight white clean fender to put on my silver car. Do I need to primer it first or just sand and apply the new paint?

Anyone?

Or is the answer already here and I missed the thread?

Can someone link me to it?

I can see that this question was not clear.

Should I put primer on the white fender or just paint it with silver after sanding?

If I should use primer, what primer should I use?

When I sand, what grades of sandpaper should I use?

BTW, this is not a trick question.. I really don't know much about paint.

I will tell you what I did. When I repainted my black Carrera the only thing I primed was the spots that had filler, otherwise I just sanded the original paint and shot it.. I used a single stage paint, I don't know if prep would be different with a base and clear?

http://forums.pelicanparts.com/paint-bodywork-detailing-forum/410852-painting-weekend.html

http://i30.photobucket.com/albums/c3...1/100_6942.jpg

Good, factory paint is a good base primer itself. IF, it is in good shape. No rock chips, cracking, checking, flaking, etc. If the paint is good and no damage, some have just used a scuff pad, and then a tack rag, to get rid of what little dust may be there, then prep-sol, before shooting the color. I have stated somewhat simplified prep instructions, but hopefully you understand what I am trying to relate to you. Good luck!! Tony.

I recently shot two stage Dupont Chroma-based paint using sanded factory paint/primer (in fair condition) as the primer. Results were good.