Whats the best way to get the surface rust and gunk off the bottom of an old car? Its not too bad, but I want to clean it up and paint the bottom. Ive ehard theres some sort of spray-on that converts the rust to something else?
I've never seen anything that works other than cutting the rust out and replacing it with good metal. It's not called "cancer" for nothing.
As Bliss said, it is called 'car cancer'. Welcome to the club buddy! My explorer has a lot of this crap on the bottom. There is no way to fix it, except to replace it with newer metal.
you could spray concentrated HCl on the bottom. That'll turn that rust into liquid pretty quick. Unfortunately, it'll also melt the rest of the "good" metal.
Wel, its not like its rusted through and needs to be replaced. Its in good condition for a 39 year old car. I know that it could be sanded down somehow, but i dont know what to use.
Some kind of gel containing phosphoric acid works pretty well in nuetralising rust and giving a sound surface to paint on. I don't know any u.s. product names but over here products like "CureRust" do the business.
You still need to hit it with a wire wheel, there are frequently miniture pits that still contain rust. People use naval jelly etc. all the time, the metal looks clean, they prime and paint then the rust is back in months. If it really is just surface rust use a grinder, then sand, rust inhibiting primer,paint. Be careful though, I've actually burned through good metal using the wrong wheel before, which really sucked.
Definitely better to get a replacement from a junkyard. To avoid rust, simply avoid anything salty on your car. Especially salt water or salty streets up north.
If it's just surface rust, you can sand it down, prime it, wet sand it with a fine grit, hit it with POR 15 or something like that, wet sand again with the fine grit, paint, and wet sand again. I've done this many times before with different cars with surface rust, it works. But if you really can, replace the metal, especially if it's a floor.
1. take a wire brush, or a grinder with the wire brush wheel and use that to rub off as much flakey rust as u can... 2. go to ur local car shop and by some rust converter. can come in a spray bottle or just a bottle where u brush it on. 3. apply to rust covered area.. follow instructions on the bottle. i apply it, leave for 10 mins, damp cloth then dry cloth... repeat to be sure.... this will stop the rust from coming back 4. if u have holes, use fiberglass and wire mesh to fill them in... then rub back to get the surface smooth, then apply spray putty and move to step 5. 5. apply a primer. 6. paint!!! ive just finished patching up some holes on my car doing this... thank god for my dad
POR 15. I use that stuff for rusty floor pans. POR 15 works Best over rust. the top coats are really nice to. http://www.por15.com/Default.asp?