dont use an acid, it's a waste of money. unless you dont have the things i'm suggesting: get a scraper of some kind (puddy knife?) to break up the most of the rust. then, use a d.a. sander w/ about 80 grit paper to clean it up even more. if you come across bondo spots, switch to a grinder w/ about 36 grit paper, but take it easy. go over that w/ the 80 grit to smooth it out. after you get the majority of the rust off, sandblast it or acid it if you wish. now you're good to go. and while blasting or using the acid, you WANT any holes that may blow to blow. if the metal is that weak, you dont want it to be there anyhow.

 

Im in newfoundland but when I get back home I will post pictures of all the rusty spots and we should go from there alrighty?

It's mainly the rockers and the inside of the trunk

 

Check with the product application sheets. usually you should not treat metal prior to etch primer.
I do a lot of reading on this subject, IMHO the best autopainting discussion group is at
http://www.autobodystore.com/cgi-bin/config.pl?index
Go to the classroom page and read the "basics of the basics" page then join the discussion group if you have questions.
Their recommendation, which I followed is to remove paint and rust with 80 grit on a polisher/sander. Treat the surface with Picklex, then for exterior areas use an epoxy primer and for non exterior use Zero Rust. Their tests indicate the Zero Rust performs better than POR, is easier to use (you can get either quarts or spray cans) and is cheaper!

 

im sorry im meant to put or i do all my post either at night or early in the morning i hadnt had my caffeine yet lol