Vinegar

[fflintstone]

It has been my experience that you do need to neutralize the vinegar or it will flash rust in no time. The best results I had were pressure washing them after the soak.

[gibsontool]

I have never had a problem with rust after using vinegar and I would think I've used it at least 15 or 20, times but it may have something to do with climate as I'm in a fairly dry area and I do tend to give the moving parts a squirt of WD 40.

[RedVise]

Vinegar is less of a mess than electrolysis for me. I do live in a humid climate and use ATF to stop the flash rust.

I have noticed that old chrome in poor condition will only take a short period of time to start flaking off rest of the chrome  when you  brush off the black crud.

Brian

[rusty]

Chrome is usually plated over copper, which dissolves rapidly in acids....
Vinegar will also eat nickel plate very quickly...

There doesn't seem to be much you can do when the chrome starts peeling in any case, once it starts, it seems to just come off in sheets...

[Aunt Phil]

Rust removal processes involving acids never cease to amaze me.
There seem to be people addicted to terrible processes like Muriatic acid which not only removes rust, it keeps eating good steel under the rust.

Oddly Phosphoric acid which can either convert rust or remove it seems in disfavor by the informationally lazy & deprived, could that be because they never heard of Google, or because any chemistry more complected than a mixed drink is too complex?

Acetic acid, vinegar is beloved, it removes rust if everything goes right, and if you preclean and if you don't mind damage to good iron.  I guess members of the Church of Vinegar never got near a vinegar generator and saw how nasty vinegar is to iron.

So, what the hell is wrong with citric acid if you insist on an acid process?  Got filth and contamination, use 2 tanks, the first dip will clean and the second tank will derust. 
I'm thinking if I was bound and determined to use acid to screw tools up, I'd go with Citric.

[amertrac]

I use enviro rust and have real good luck. But the oil on peice has to be removed before and put back on sfter. I understand they came out with enviro rust-b -gone which is supposed to be better but expensive
bob w.

[Bob Culp]

Aunt Phil already said it -- DON'T USE VINEGAR ON IRON!

I've used vinegar several times to take rust off of wrenches -- always worked fine. Then I tried it on a cast iron bevel protractor for a Starrett combination square -- it ruined it. I hate it when I'm stupid, but it sure won't happen again (at least with vinegar).

[Branson]

Well, lbgradwell's photos put an end to the argument (one fellow insisted vinegar was an urban legend, and that it didn't, in fact *couldn't* work.  Now he thinks he might try it.

The big fan club was all for  phosphoric acid.  One guy liked the citric acid found in cool-aid.  His point was that the citric acid in that process was more concentrated -- the acetic acid in vinegar is only about 5 percent.

 

[lbgradwell]

Well, lbgradwell's photos put an end to the argument (one fellow insisted vinegar was an urban legend, and that it didn't, in fact *couldn't* work.  Now he thinks he might try it.

Cool. Link?

[oldtools]

Phosphoric acid, also sold as Ospho Metal Treatment. I use this when doing body work to Stop rust. works great!! (Converts rust to a ceramic like finish that you can paint over)
 per Bing;..
Phosphoric acid may be used as a "rust converter", by direct application to rusted iron, steel tools, or surfaces. The phosphoric acid converts reddish-brown iron(III) oxide, Fe2O3 (rust) to black ferric phosphate, FePO4.
 
"Rust converter" is sometimes a greenish liquid suitable for dipping (in the same sort of acid bath as is used for pickling metal), but it is more often formulated as a gel, commonly called "naval jelly". It is sometimes sold under other names, such as "rust remover" or "rust killer". As a thick gel, it may be applied to sloping, vertical, or even overhead surfaces.

[rusty]

NB: Be aware that some of the rust conversion products also contain vinyl paint....

[Aunt Phil]

Be aware Ospho is a complete total RIPOFF hustle SCAM.

Phosphoric is available in a hell of a lot of product, and depend on on concentration can either convert rust or remove rust.

Some converters contain dissolved zinc and magnesium.  They ain't worth the extra money

ALWAYS KEEP PHOSPHORIC AWAY FROM ALUMINUM

Rusty you meant to say polymeric coating, didn't ya, relative to Paint Over Rust slop.