priming over rust

[Lincolnmania]

i have a bronco two that the paint has long peeled off of the tops.......the roof is solid surface rust, virtually no paint left
if i sand the roof with some 80 grit, what type of primer do i need? i used to work in a bodyshop as a mechanic, but i never mixed paint (although i've done some priming and painting lol) please help save the bronco lol
scott

[Cogs]

Well, if you dont want it to rust, then don't leave it just primered. You NEED to prep it right and get it painted before moisture can get in.

That said, theres no need for 80 grit. 320 will probably take it off, depending on severity. If 320 doesnt work, do 150, dont go any lower. IF you need to use 150, go over it again with 320 and some more various higher grit papers to smooth it, other wise, your paint will look like crap. You'll have big gouges and such, even with 320 you can see them still, so try 600 or 800 after, or both.

I think there is some kind of rust inhibitor spray you can get. It's not neccesary, but would probably be a good idea, unless you plan on getting the whole car painted sometime soon?

THeres 2 different primers you can use that I can think of right now...regular primer, and filler primer. Filler primer would be used if you still have little scratch marks or very low spots, things like that. If you dont care, just use regular primer.

PAINT AFTER YOU PRIME IT! Primer absorbs moisture, so the rust you just sanded off, its gonna come right back as soon as it rains. Also, same with bondo, if you plan to use that too.

Hope that helps ya.

[Cogs]

I just reread your post...you're not actually thinking of painting OVER the rust are you?! If so, DONT! You need to sand it all off. Every little bit. Otherwise, it will come back to haunt you. Your paint will bubble up and it will make a lot more work for you later.

[Ifixyawata]

Yep, Cogs is really right. If there's even little pits with rust in them you've gotta get it out or it'll be there again. And, contrary to popular belief, primer does not stop rust. Only a topcoat of paint will.

[grandpaslincoln]

Let it rust through, have a really nice skylight. :coocoo:

[Revolution_909]

Yea thers a rust inhibiter thing.. taht you will need. put taht on after you sand b4 priming...

[zwack88]

That is one thing I did wrong when doing bodywork on my old pickup. I left it in primer and about 2 months later I could see rust. Prime then paint.

[85crownHPP]

And, contrary to popular belief, primer does not stop rust. Only a topcoat of paint will.

D'OH!!!! I have some painting to do....

[Revolution_909]

Me too i can see the rust again