Thread: Cleaning Vinegar

AFAIK just use the vinegar as is. It's a solution of acetic acid and the acid combines with iron oxide to form a new compound.

I've used Phosphoric acid on plane bodies but frankly wouldn't bother again as some form of abrasion is required anyway to get the black stuff it creates off. That's if you want a shiny finish. If not, it can just be wiped off and painted over.

PS, a vinegar recipe from Witch is here

I've used Citric Acid to good effect. Readily available and not expensive it's found in the cooking section of Super Markets. Here's a pretty good run down of the process:
Removing Rust with Citric Acid by James D. Thompson

Molasses works really well. It is slow, but very thorough. Use a mix of about 1 part mollases to 6 or 7 parts water & soak tools. The mollases conyains mild chelating agents & will remove rust but not etch the steel. Mollases derived from sugar beet is best, as it contains more hydroxamic acids, which act sas the chelating agent. (The chelation process involved is able to pull iron from the iron oxide - rust - but is not strong enogh to pull the iron aytoms from the underlying metal)

There have been other threads on this forum about the molalses process

Thank you for the helpfull responses.
I have immersed one gouge blade in undiluted cleaning vinegar overnight and then used a postage stamp size scouring pad on a power drive to polish the black (oxide ?) off.
The metal surface is much brighter and close to my target finish.
Just needs to be re-sharpened and honed ready for use.
A worthwhile exercise, and just as importantly, low cost and effective.
Four more old gouges to do.
Thanks.

I use cleaning vinegar to sharpen my metal files ,It works well.
I have resurrected around 60 old files I had floating in the bottom of an old tool box for a lot of years .
Just have to make up enough handles to fit to them.
Incidently ,cleaning vinegar is brewed from Molasses.

Kev.

Vinegar (or other mild acids for that matter) will certainly remove rust.

Vinegar contains acetic acid CH3COOH which reacts with rust (FeOOH) as follows:

3CH3COOH + FeOOH --> Fe(CH3COO)3 + 2H2O

As iron (III) acetate Fe(CH3COO)3 is water soluble, it is readily removed.
(I'm simplifying - rust contains several forms of iron oxide & iron hydroxide)

Phosphoric acid is used in 'Naval Jelly' and end up with ferric phosphate, which can be removed, but is often left in place as an oxygen barrier & primer for painting.

But as Woodlee has discovered, vineagr will also etch steel (and so sharpen his files).This will also etch your tools when removing rust . The chelation reaction from molasses is quite different & is likely to cause less damage to the steel, although there is some acid in the molasses solution (you might notice a vineagr like smell after a few days.)

For rapid rust removal where you are not too worried about preserving detals in the underlying metal (eg You are going to paint the metal afterwards) , acids are fine. If you are wanting to be as kind to the metal as possible, I would suggest using the molasses.

Or you can use electrolysis. In cases of heavily rusted iron it is possible to convert some of the underlying rust back to iron. See this article for some details.

Another technique for light rust removal is by use of aluminium foil. Rub the steel with aluminium foil dipped in water. Aluminium has a higher reduction potential than the iron in steel, which may help transfer oxygen atoms from the iron to the aluminium. The aluminium foil is softer than steel and will not scratch it, as steel wool will, but as the aluminium oxidizes, the aluminium oxide produced becomes a fine metal polishing compound. Rubbing with copper also works, and in the old days a penny was sometimes used to rub out light rust on steel.

Thanks Ross, finally an answer that makes sense.

I've tried different methods and had mixed results, now I can understand why.

My preferred method is electrolysis so the info in your link will help me refine my process and hopefully improve my results.