If I were to buy something like a hood and leave it primer black... Would it be ok to leave it like that for some time? Or would it have to be re-primer'd or something before I decide to paint it?

 

Primer would definitely be better than letting it sit like it is. Of course standard prep work will be required before painting.

 

i am asuming you mean the black that comes on a new sheet metal hood when you buy it. you could run it like that but it will rust. primer has no ability to keep moisture out and away from the steel it will cause rusting under the primer.

jeff