Surface corrosion on crank

[Lee29coupe]

I am in the process of buying a great 31 crank shaft which is stock sized, never reground. It has slight corrosion that I know can be cleaned up by hand. How would I do that, what would I use to do it?

[john charlton]

I cut a strip of 2000 grit 3 M paper and apply WD 40 .I cut the strip the same width of the journal and long enough that I can rotate it around the journal while I pull it too and fro .

John in Suffolk County England .

[PC/SR]

crocus cloth as well.

[katy]

Ditto on the crocus cloth.

[Synchro909]

What the $%^ is crocus cloth??? I've never come across it.

[hudson32700]

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Crocus cloth is a cloth strip embedded with very fine iron oxide rather than abrasive grit, as in sand paper.

[Synchro909]

Originally Posted by hudson32700

Crocus cloth is a cloth strip embedded with very fine iron oxide rather than abrasive grit, as in sand paper.

OK, got it - it's a rusty rag!

[nkaminar]

I have used crocus cloth on journals and it works great. See https://www.mcmaster.com/crocus-cloth/

[Ray64]

I have crocus cloth that looks like fresh picked cotton in a can. Never knew it came like rolled paper.learn something new all the time

[jrelliott]

Went to hardware store in Payson, AZ and no one knew what I was asking for. Have used it several times on cranks and other shafts. It is great.

[katy]

Originally Posted by Ray64

I have crocus cloth that looks like fresh picked cotton in a can.

Never knew it came like that. Learn something new all the time.

A picture or link would be appreciated. Got nowhere fast doing a web search.

[arnhemmer]

Try Amazon

[Benson]

I had same problem finding crocus cloth ...

Try Emery Cloth ...

Google finds many more hits than crocus cloth

[BRENT in 10-uh-C]

Y'all use crocus cloth or emery paper if you like, but I personally would use cork only to deburr it and then leave the rest alone. Using any aggressive media on it will quickly egg-shape the journal pin and IMHO causing bigger issues than what the corrosion is.

[Bluedevil]

Take the above mention cloth, wrap it around the journals then use a wide shoe string and wrap it around the cloth twice and then pull the ends back and forth. Makes it easier to polish it.

[Bluedevil]

https://www.bing.com/images/search?v...t=0&ajaxserp=0

[nkaminar]

The crocus cloth is not aggressive enough to cause an egg shape journal. It just polishes. Of course it must be used over the entire 360 degrees of the journal in a uniform manor. I did one journal of a friends 1924 Buick that had a rod knock. I checked the journal with a mike afterwards and there was no out of round or difference lengthwise. I took some shims out of the rod bearing and the car was run like that until my friend recently passed away. I don't know who ended up with the car but it is probably still being run that way.

https://www.mcmaster.com/crocus-cloth/

[Bob C]

Originally Posted by Bluedevil

Take the above mention cloth, wrap it around the journals then use a wide shoe string and wrap it around the cloth twice and then pull the ends back and forth. Makes it easier to polish it.

When I worked at a Porsche dealer that's how the master mechanic
used to polish a crank except he used a piece of string.

[Crankster]

Why is it called "Crocus" cloth? Are there little crocuses embedded in the paper or something? How about "Emery" paper? Named after some guy in Michigan at the turn of the century?

(How many here know for example grease Zerks are actually named after the inventor, Oscar Ulysses Zerk? It's true.)

Thus concludes today's installment of interesting, but probably useless information.

[BRENT in 10-uh-C]

Originally Posted by nkaminar

The crocus cloth is not aggressive enough to cause an egg shape journal.

Hmmm, maybe not to a naked eye but I'd bet you'd retract that statement if you watched me measure it with an Arnold gage on my crankshaft grinder after someone polishes it with crocus paper.

My target when grinding a Model-A crankshaft is 0.00025" (i.e.: ¼ thousandths) of concentricity. My machine (Storm Vulcan Model 15) will hit that number repeatedly, therefore I know from experience what emery paper will do. We do not use emery paper anywhere near a crankshaft pin.