Bicycle Mechanics - Citric Acid for rust removal?

Has anyone here used citric acid for rust removal?
How well did it work?
How long did it take?Concentration?
I'm planning to use it on some small parts and a frame.
Thanks.Charlie

Has anyone here used citric acid for rust removal?
How well did it work?
How long did it take?Concentration?
I'm planning to use it on some small parts and a frame.
Thanks.Charlie

Citric acid is, er.., an acid, so I think it will make more rust more than anything else.
If you have physical access to the parts (i.e. not inside a tube), you can remove the rust by polishing the parts with soft emery (grain 400 or more). If you don't want to polish things, ask your local gunsmith if he can get you a can of Parcodine: this is a rust remover that works great, just dip the parts in it, leave them for 10 minutes, and recover them shiny and pristine.

Yes, citric acid works as a rust remover and will not harm the base metal unless you badly over dose it. I'm not sure of the best concentration but try about 5 to 10% in hot water. Pay attention so you rinse the parts when the rust is gone, don't just soak them unattended overnight. A rinse in household ammonia or a weak baking soda solution will neutralize the residue.

A better approach is one of the phosphoric acid based commercial rust removers like "Naval Jelly".

BTW, note to ppc. Not all acids are the same. Citric and phosphoric are very common ferrous metal cleaners and won't damage the base steel or iron.

I wonder if citric acid is the active ingredient in those bio-safe parts cleaners like the one I buy from Performance. It works well, doesn't make a mess, and smells okay. But don't leave parts in there too long. I did that with an old derailleur, and some of the aluminum came out dull looking, and the printed logos all but disappeared. Luckily, I already had a replacement for the component.

EB

Citric acid is, er.., an acid, so I think it will make more rust more than anything else.
If you have physical access to the parts (i.e. not inside a tube), you can remove the rust by polishing the parts with soft emery (grain 400 or more). If you don't want to polish things, ask your local gunsmith if he can get you a can of Parcodine: this is a rust remover that works great, just dip the parts in it, leave them for 10 minutes, and recover them shiny and pristine.
Any kind of acid will take the rust right off. White vinegar is probably stronger than citric acid, and you might be able to find stronger acids at a hardware store.

em

Any kind of acid will take the rust right off. White vinegar is probably stronger than citric acid, and you might be able to find stronger acids at a hardware store.em

Yes it will but that's not what you want. You want an acid that will specifically disolve rust (or hard water scale) without seriously attacking the base metal. Citric and phosphoric acid fall in that catagory. Stronger acids like muratic (HCl) and sulfuric will indeed remove rust. And everything else too.

BTW, white vinegar is 5% acetic acid and good for dissolving hard water scale but not typically used for metal cleaning.

Just when I'm about to start a thread about using vinegar to do this, it's laid out in front of me. I'll be trying this out with vinegar soon, then following up with turtle wax polish, maybe some dremel buffing work.

I'm not sure how long it would be safe to leave parts in vinegar - I left my seatpost sticking down in the bottle overnight....about 12 hours total I guess, and there is a noticable line of shininess where it was submerged. I think I'll be going out for a new jug or two and soaking several more parts next week. I think I might leave them in there for a full 24 hours. Most of the stuff I'm trying to clean isn't rust, though, so I can't speak for how it might work with that.

This thread has a bit: http://www.bikeforums.net/showthread.php?t=168462&page=2&highlight=vinegar
The recommendation for electrolysis sounds good, if a lot of metal must be cleaned.

Thanks all.I had heard about citric acid removing rust-a citric acid prep is sold in many MC magazines and car mags.However that prep is pretty expensive-.I bought 2.3 lbs off Ebay for $12 delivered.(they sell it for "bath bombs"??.
I won't be soaking the entire frame-I don't have a container that big or enough citric acid.I'll soak the parts and parts of the frame-bb-rear dropouts-stays-that can be "dipped" in a small bucket.Other parts of the frame I wrap with wet cloths-held on with rubber bands.Thanks-I'll ley you know how it goes.Charlie

............ wrap with wet cloths-held on with rubber bands..........

If you wrap the rubber bands too tightly then they will just compress the rags, and sqeeze the solution out of the areas under the rubber bands. Loosely wrapping with saran wrap will prevent this, and help to avoid a dripping mess, too.

Then again, a dripping mess is really only a problem if you're working in your living room, etc. (Not that I'm dumb enough to work in my living room, or anything like that ;) )

brisle brush or 400 grit sand paper removes surface rust well, it takes time to get it off but it works

Spunkyruss-saran wrap-hey,I like that idea.It might turn into an indoor job,so I will give that a try.
russiankdi-I started out with 600 grit and coarse steel wool on the 1st spot-then I gug up some coarser paper-you are right-a lot of work.Of course,I'll still have to smooth out the defect that is left after the rust is removed.I think I'm going to dab some cheap paint on the defects after the rust is removed ,just to see if the defect shows thru-no point in taking off any more metal than I need to-beside-as you pointed out- it is a lot of work!!.Thanks.Charlie

Spunkyruss-saran wrap-hey,I like that idea.It might turn into an indoor job,so I will give that a try.
russiankdi-I started out with 600 grit and coarse steel wool on the 1st spot-then I gug up some coarser paper-you are right-a lot of work.Of course,I'll still have to smooth out the defect that is left after the rust is removed.I think I'm going to dab some cheap paint on the defects after the rust is removed ,just to see if the defect shows thru-no point in taking off any more metal than I need to-beside-as you pointed out- it is a lot of work!!.Thanks.Charlieno problem, i learn everything the hard way. My parents dont buy me everything that i need so i have to repair everything myself, but yes i bet your hand is hurting right now

oh forgot to mention, wire brush which can be bought at any store liek home depot, you can put it on your drill and the wires remove the rust. Much easier