Best way to remove bearing material "Stain" from crank?

[Richard48Y]

I have a TR6 engine that was built for a racing car.
It has some trick pieces in it.
But it also sat never run for a very long time.
I have to be glad it was never run as the builder made some errors that would have been fatal to it, white lithium grease is not assembly lube!
I've taken it apart for cleaning and careful reassembly.

The issue I need to address is that there is a very thin layer of bearing material adhered to the crank journals at random spots.
Polishing with fine emory paper and crocus cloth is a given.
But first I would like to remove the bearing material stain chemically to help ensure the surface remains even.
I am looking for suggestions that will not etch the steel or incite rust.

Completing this and getting it back into the chassis will provide me a salable asset to fund finishing the Europa.

[dakazman]

  Nothing comes to mind chemically, have you tried scotch brite pads or Dremel pads
Search / 40Pcs 25mm Scotch Brite Scouring Pad Polishing Mop 3mm Shank Nylon Fiber Wheels.
  Emery and crocus is very abrasive.
Dakazman

[4129R]

Wire wool ?

[BDA]

If it is something stuck on the crank, would a credit card scratch it off?

My engine building buddy showed me his journal polisher which is a cork covered belt. I think I would try that first since it seems the least invasive. If I used wire wool (we normally think about it as steel wool in the States), I think I would use copper wool since it's softer.

[Richard48Y]

I would just send it to a local machine shop to be done if they were not all either closed down or months away from getting to it.
I will try a couple of test.

[GavinT]

1. Plastic razor blades as per pic? These are much more robust than might be expected. Good for cleanly removing the price sticker off that Cartier watch or Mecaparts parcels, too.

2. Brass brush?

3. Give the bearing material a quick hit with a propane torch? It's only lead/tin so would probably bobble up and there won't be enough heat to worry the crank.

Personally I wouldn't worry about the staining. I'd expect that to come off with the polishing and if it didn't . . well.

[Richard48Y]

I have mounted the crank in my lathe to make it much easier to handle.
I had not thought of the propane torch, I will try that, gently.
I think I will also split some paint sticks to be narrow enough to support fine scotch-bright type pads since my fingers are not doing very well.
Final polish will probably be crocus cloth at 1,000-1,500 grit.

[GavinT]

Well, if it's mounted in your lathe, that's so much easier.
A guy I worked with used a worn out/blunt length of fine emery cloth with copious amounts of kerosene for a short first pass. That got rid of all the crud/discolouration and then proceeded with a paste metal polish on a length of calico cloth. T'was pretty shiny after that and all done quite quickly, too.

[Richard48Y]

Fortunately I have remembered to turn the crank around before polishing.
Always polish in the direction of rotation!
I have gathered some supplies to try in the morning.
Actually looked at buying a proper machine, the least expensive is about $450.00

[Richard48Y]

Found a machine shop that will get to it in only a week, $60.00
Dropped it off on Monday.

[dakazman]

 Thanks for the tips
Dakazman