Clean and restore Mitutoyo dial caliper

[GreatOldOne]

My friend recently purchased an old dial calliper from eBay, and asked if I could try and polish out the scratches in the crystal. So I gave it a go, and whilst I was at it stripped it all down and gave it a thorough cleaning, as it was real grotty in places.

Before:



During:


After:


Everything was cleaned in isopropyl alcohol, and the crystal was polished with 120 thru 2500 grit wetndry, finally finishing off with a cotton mop on my Dremel with some polywatch plastic crystal polish. It’s got it nice a clean with all the deep scratches out - but has highlighted that the two worst scratches are in fact cracks. He’s going to run with it for now, and probably get a new one later.

 

[mikey]

You did a really nice job on that! Is it accurate?

 

[fixit]

you should go into the repair business. GREAT JOB, young man.

 

[thomas s]

very nice can I send you a few for repair lol.

 

[GreatOldOne]

You did a really nice job on that! Is it accurate?

Yes, it’s accurate. Checked with my gauge blocks.

you should go into the repair business. GREAT JOB, young man.

Thank you!

very nice can I send you a few for repair lol.

Shipping may be prohibitive...

 

[tmenyc]

do you know what the crystal is made of? Is it a plastic of some kind? Almost any plastic can be solvent welded and polished so the crack is gone.
And yes, phenomenal job! Encourages me to go after the old yellowed Starrett I have; I think it was yellowed by being in a kerosene-heated shop with a heavy smoker...

Tim

 

[GreatOldOne]

do you know what the crystal is made of? Is it a plastic of some kind?

Yes, it’s plastic. I would guess it’s some form of polycarbonate. Sanding out the scratches produced the same sort of fine particles and plasticky smell as sanding and buffing out lenses on non glass headlights.

 

[brino]

It’s got it nice a clean with all the deep scratches out - but has highlighted that the two worst scratches are in fact cracks.

Nope can't polish those out.
Very nice job!
-brino

 

[tjb]

Beautiful work. Just last week, my daughter-in-law found a Mitutoyo 505-625 dial caliper and gave it to me. It's in very good condition but a little grimy. Your post encourages me to try to give it a good cleaning. Thanks.

Regards,
Terry

 

[Janderso]

Outstanding work!!
I have an old Brown and Sharpe that needs the same attention.