Phosphoric Acid on rust turning metal black....

[budsaipan]

Do anyone have experience using this product? Today I picked up Kleen strip and etch (phosphoric acid) to help with my rust removal. I stripped most of the big rust out with a grinder and wirewheel then I sprayed some of the phosphoric acid on the rusted pits and such. Now I'm left with alot of black pits. How do I remove those black rust pits?

[DanielC]

Here is another car forum's thread about rust removal.

http://www.hotrodders.com/forum/secrets-surface-rust-removal-revealed-55679.html?highlight=Rust+removal.

Have a good read.

[ggzilla]

It's supposed to turn it black, that means it worked. Now you smooth it out before painting.

[budsaipan]

I keep getting different opinions on this. I guess they best way would be to sand blast it all off. For now I'll just paint over it.

[merlin]

I just used it on my snowballs chance build... It isn't really a good rust stripper... Sand or blast that offf, but it is an excellent etcher converter.... You really need to clean off all the excess afterwards... I ended up washing the whole car with soap and water and a very mild scotchbrite pad.

[Guest DatsuNoob]

I used it, worked great! After I applied it, I put on some rubber gloves and scrubbed on it with a scotch brite pad, then finished up with a Marine Clean scrub with warm water. The surface rust scrubbed right off and I was left with a clean paintable panel.

[INDY510]

.

I used it 12 years ago on really rusty 510 floors after grinding and wire brushing most of the rust... .. and it turned the floors black

 

 

....painted with Hammerite ..... . . 6 years later the paint was still there but I could put my foot through the floor because it was rusting under the paint .... :o

[izzo]

Sand it down to bare metal, get one of those 3M flapper discs thats made for taking down paint. (works good, just ask skunk) Then por15 your floors. Itll never rust from the top.. Then youll need to do the bottoms

[budsaipan]

Alright, great info guys. So I let the phosphoric acid sit overnight and all my floors turned black this morning. I took some water and wiped it with paper towel. Those black stuff just came off easily. It's like black ashes. I think I'm going to wire wheel the area and make sure I get all the rust out or as much as I can then shoot primer.

 

I heard bad things about por15 as well. I'm going with epoxy primer the top layer and por15 the bottom of the cab...

[Guest DatsuNoob]

Yes! That's right Budsaipan. POR-15 is total shit if layed on top of a poorly prepped surface. It peels off like black saran wrap. Everyone is so quick to praise it, but you gotta really follow manufacturers instructions or it sucks. 2 coats is what they reccomend with a layer of POR-15 on bottom and Frame and Chassis black on top if you want a truly lasting finish. Not preaching bs here, I've had mixed results with POR, for some things it's great! for others not so good. Doesnt handle oily surfaces well at all either :D