De rust 100 year old crankshaft, citric?

[Matchless]

I have citric acid powder (food grade) and a surface rusty crankshaft from my 1914 Hedstrom Indian, steel rods, flywheels may be cast or forged, not checked, pistons are cast iron, it is all a bit rusty but not seized at all, would a citric acid bath be the way to go, It may well have bronze big end bearings or rollers, I will check but suspect bronze, all feel good so not intending to dismantle the flywheels unless I have to,
what ratio to mix the citric powder, does it attack aluminium or other metals? etc. advice needed please..

 

[Brad93]

Electrolysis.

Citrix will eat the bronze

 

[Seadog]

So will phosphoric.

 

[dieselsamurai]

Pretty sure citric and phosphoric attack aluminium too

 

[Brad93]

Electrolysis with baking soda as the medium should be fine.

 

[Sergei Slovenija]

The most gentle agent for dissolving oxides is EDTA

Ethylenediaminetetraacetic acid - Wikipedia

en.wikipedia.org

After complete reaction with the oxides, and converting them to soluble salts, EDTA will begin to dissolve the base metal. The exposure time in the solution must be controlled.

 

[eddie49]

EDTA works by the process called chelation, the removal of metal ions. More details and examples of products here:

A brief guide to rust removers

The ability to remove rust is essential to giving new life to objects of iron and steel.

cottagelife.com

 

[tigdlo]

I used MC-51 on my ML7, did a very good job, couldn't soak the bed so used wetted paper towels, I was impressed with it but don't know if it would be suitable for your application.

 

[brightspark]

i wouldnt be happy de rusting the crank without splitting it. any contamination on the bronze bearings will trash it and end up as grinding paste

 

[Rannsachair]

i wouldnt be happy de rusting the crank without splitting it. any contamination on the bronze bearings will trash it and end up as grinding paste

That was my first thought too.

 

[Matchless]

everything has a risk attached, splitting a 100 plus year old crank could end badly, if I feel I have to I will, the axles may be too pitted to carry on and may need either hard chrome or metal spray, or even new ones made I will play it by ear, there is no oil feed to the big ends, just splash, I have washed cranks before and then dropped them into a bucket of oil for a good soak,

 

[Matchless]

Ok, I will come clean, @Brad93 welded that up for me!

 

[Brad93]

I can spray cranks and cams

 

[Brad93]

It's been a busy day for the ultrasonic cleaner

 

[brightspark]

would come up nice now if they were bead blasted

 

[Brad93]

would come up nice now if they were bead blasted

Expensive pat was saying?

 

[Sergei Slovenija]

EDTA works by the process called chelation, the removal of metal ions. More details and examples of products here:

A brief guide to rust removers

The ability to remove rust is essential to giving new life to objects of iron and steel.

cottagelife.com

This is what makes the product re-usable. Because the chelator is not strong enough to break the iron-to-iron bonds of sound steel, it doesn’t harm uncorroded metal.


An aqueous solution of EDTA corrodes the metal. This is easy to check with a gauge tile (not rusted) + a micrometer with a division in thousandths. First, polishing will disappear, then microns of steel will begin to disappear.

 

[Matchless]

Expensive pat was saying?

I can bead blast them at home now they are clean, was looking at vapour blasting and ice blasting, but this will work out ok, now we are retired I will not get a chance to run them through the dish washer..............

 

[northwest]

Expensive pat was saying?

To do the bead blasting?

 

[Matchless]

To do the bead blasting?

No, the ice and vapour blasting plus driving there and back twice,