Ok so ive been told in the past after wire wheeling away rust before primering i should treat the bare metal with some type of acid I can get at homedepot to prevent rust from coming back/flashing. Any ideas on this? I was told to do this for pin holes/smaller holes as I am having trouble welding them in and I can just put some like filler over them. Ive been cutting out and patching holes and was wondering how I keep the back side of the metal from rusting. For instance on the bottom of the quarter right behind the door. I cant get to the back side of it.
Filler is not a replacement for metal when it comes to holes, no matter how you treat the metal. It WILL come back. You can get to the back of that metal (bottom of the quarter right behind the door) by taking out the back seat and the rear side panels.
you can also use weld-thru primer for the back sides of metal that will be hard to get to when welded in place. Pin holes will always grow when just covered over. If there are enough of them the right way is to replace a whole section with new metal.
ok. Well I guess my main question is still unanswered. What do I treat the metal with before painting to prevent rust? acid wise that is. Also I can fill in holes and itll be fine?
Rust Converter is what it sounds like you're looking for. There are numerous brands, and you can get them in either an aerosol can, or in larger amounts in gallon and up containers. The ones I've used turn the rust black after you spray it, and the rust is neutralized at that point. Not sure chemically what the compound is though. I think I actually picked up a spray can at WalMart before...but can't guarantee they still carry it.
It's been a long time (20 years) since I totally took a car to bare metal, but you need to use a "Metal Prep"...............this does not convert rust, but desolves it and turns the metal kind of yellowish tint.......but you leave it in the rain for several days without any flashing. I know you can buy it at a paint shop that sells automotive paints, like a PPG shop. It comes in a can with a picture of a plane on it, and is used in the Aerospace industry. It's is really the only thing you should use before priming bare metal...........IHMO
As I said....the rust will come back...even if treated...around all the pin holes. It will not last. As Paxtond said....replace with metal.
Self Etching primer is what you are talking about, It has acid and zinc. It is used on bare metal. You can get at a auto body supply store.
Phosphoric acid (spelling?) Is what you seek Or you can just use OSPHO it is great stuff and does exactly what it claims. http://www.ospho.com/ You can get it at ace hardware and probly some other places
yes thats it! ospho. Thanks! Does anyone know how to use just phosphoric acid and the difference between the two?
I think it is Oshpo X20. The difference between Oshpo X20 and Phosphoric acid is that you have to neutralize the acid with water, where you don't with Oshpo X20.
And don't use Ospho on concrete unless you neutralize it right away while it's still wet. Ask me how I know...
