What grit to polish a crankshaft?

[ebinmaine 67,695]

The replacement crankshaft that I got for Trina's 657 hh-60 has a tiny little indented nick in it.

I feel that it's okay to use but I'd like to make sure there's no high spots on the nick.

For some reason I can't find 400 grit Emery cloth locally so I'm wondering if I'm looking for something too fine?

 

Is 320 grit okay or too course?

[Stormin 9,981]

Eric, I wouldn't use emery to get rid of the nick. Best thing is a flat fine oil stone and hydraulic oil or paraffin. Kerosine I think you call it over there. 

 You can use fine emery to finish off.

Edited August 30, 2019 by Stormin

[ebinmaine 67,695]

47 minutes ago, Stormin said:

Eric, I wouldn't use emery to get rid of the nick. Best thing is a flat fine oil stone and hydraulic oil or paraffin. Kerosine I think you call it over there. 

 You can use fine emery to finish off.

 

 

Is it okay to use a flat stone on a round crankshaft?

I'd have some concern about creating a flat spot...

 

[pacer 3,174]

I use automotive type 'wet or dry' - it comes in about any grit imaginable. Tear it in a strip that when folded it fits the surface youre working on and with a spray can of WD, or similar, keep it wet. I have a lathe and mount the shaft in it and go at it.

 

I keep 4-5 different grits of 'wet/dry' on hand and find all kinds of uses for it.

[Stormin 9,981]

7 minutes ago, ebinmaine said:

 

 

Is it okay to use a flat stone on a round crankshaft?

I'd have some concern about creating a flat spot...

 

 

 Just be careful. Try to keep it in the bad spot rocking it. Don't go round the crankshaft. And just use a small stone.

[ebinmaine 67,695]

3 minutes ago, pacer said:

I use automotive type 'wet or dry' - it comes in about any grit imaginable. Tear it in a strip that when folded it fits the surface youre working on and with a spray can of WD, or similar, keep it wet. I have a lathe and mount the shaft in it and go at it.

 

I keep 4-5 different grits of 'wet/dry' on hand and find all kinds of uses for it.

I assume we are talking about regular wet dry sandpaper?

it's been 20 plus years since I've messed with engines much and we were told back then to only use cloth. Not paper.

 

[Stormin 9,981]

2 minutes ago, pacer said:

I use automotive type 'wet or dry' - it comes in about any grit imaginable. Tear it in a strip that when folded it fits the surface youre working on and with a spray can of WD, or similar, keep it wet. I have a lathe and mount the shaft in it and go at it.

 

That method I would use to polish down any lines round the shaft. But Eric has only a nick.

[Stormin 9,981]

I'd use emery cloth.

[pacer 3,174]

1 minute ago, Stormin said:

Eric has only a nick.

 

Good point! For that I have - and dont remember where I got them - a set of maybe 8-10 square/oval/round/etc hand held stones in various colored grits. They may have been from a machining catalog??

 

 

[Stormin 9,981]

Just another point. The nick or indent will have any high spots round the outside edges. Get rid of those and all should be fine. Don't try getting rid of the whole indent. A little concave mark won't matter.

[ebinmaine 67,695]

8 minutes ago, Stormin said:

Just another point. The nick or indent will have any high spots round the outside edges. Get rid of those and all should be fine. Don't try getting rid of the whole indent. A little concave mark won't matter.

Yep. That was exactly my line of thinking.

 

[oliver2-44 9,765]

We used the fine White Arkansas stones to hand rework the large hydro turbine "18 - 30" journals at the plant, when the shaft wasn't being shipped off for other repairs. If we needed to work out a scratch or something we used "crocus cloth "  

Crocus cloth is an abrasive sheet similar to sand paper or emery cloth but covered with a layer of very fine loose iron oxide particles rather than with bound grains of abrasive. It is intended for final metal and gemstone finishing and is available in various grades (particle sizes).

[ebinmaine 67,695]

2 minutes ago, oliver2-44 said:

crocus cloth

Yeah that's what I was trying to find around here. I'll be darned if I can put my hands on it. I may have to just wait and go mail order.....

[JCM 9,202]

Eric, try a company called E.C. Mitchell Co in Middleton Mass they have Abrasives Round Cords and Flat tapes, I can show you a roll of their cords that I may have to look for but I would not have any flat tapes which is what you need.This Company was one of my best Customers for many years and is now under new ownership, when I see you at the M & G next week I will tell you the story behind this great Company. also their products are I believe are available through Mcmaster-Carr.

[ebinmaine 67,695]

21 minutes ago, JCM said:

E.C. Mitchell Co

I will absolutely check that out later. Thank you Jim.

[oldredrider 2,548]

Went in to Lowes one time looking for crocus cloth. Guy in the tool section said "never heard if it, what is it?" Told him he shouldn't be working there and I left.