Removing rust from head nuts and washers

[bbh03]

I know these parts must be stored in oil to prevent rust, but upon removal, I see they are already rusted. Is there a mild way to remove this rust? I have access to a number of laboratory chemicals and a fume hood, but I don't want to use something that will corrode it worse. Right now, they are soaking in hexane to remove the old sludge, but as expected, this does remove rust.

Thanks!

Brian

[jpnovak]

Ahh yes, chemistry at work...

A little Na/KOH will quickly strip all the grime without damaging the metal. Its all about hydrolyzing the grease, not just dissolving. I personally like a mixture of Oxalic (20-30% wt) and Phosphoric (2-5% wt) to strip the rust. Should only take a short time before they gleam. Don't forget to rince well with water and then coat with a thin layer of oil. Muriatic acid (HCl) also works well but is not forgiving if you leave the parts in too long.

[bbh03]

Thanks - I'll hunt down some oxalic and phosphoric. If I had to resort to HCl, what conc. would you recommend to minimize corrosion, but still be effective ont he rust?

Any neat recipes for the aluminum parts? Obviously I need to avoid base unless rinsed very well...

[bbh03]

Didn't have much luck with the oxalic and phosphoric. I used 18% HCl in an ultrasonic bath for about 20 min, rinsed well, dried with acetone, and stored immediately with oil. Thye are far from shiney, but not rusty. How shiney should they be? They have a very dull grey color and are somewhat pitted from the rust on the outside.

[BK911]

I didn't do very well in chem. So I just use a bench grinder with a wire wheel. Works every time.

[blue82coupe]

BK911.. I used vinegar in a 2.5 lb plastic coffee container. Swished it around swiftly. then let them soak overnight. It's low tech, but it worked for me.