micrometer restoration

[Kiwi BlokeParticipant @kiwibloke62605]

Well done – it's satisfying to resurrect the dead, isn't it?

As far as I can remember, all the micrometers I've had to lay hands on have been lubricated with a smear of grease, but of what type I know not. I've found that, after a thorough clean, light oil can result in an inconsistent feel, particularly when the thread-closing collet nut has been tweaked enough to provide enough drag for the ratchet to work.

I recommend what's known as 'anti-scuffing paste' or 'assembly paste' or similar. It's a grease, heavily loaded with either molybdenum disulphide or graphite. It offers protection from thread galling, especially when, for example, steel runs against steel. I prefer the MoS version. It has innumerable uses in the 'shop. Available in tubes, from engineers' merchants. A tiny amount goes a long way. You can use a drop of oil as well, if the grease is too 'draggy'.

Edited By Kiwi Bloke 1 on 22/11/2015 10:05:01

[Paul Relf-DaviesParticipant @paulrelf-davies37806]

Hmmmm…would that be similar to the Moly grease I use to pack wheel bearings & CV joints?

P.

[Gordon WParticipant @gordonw]

I would not worry about the ratchet working, they are not essential and we were told not to use them. They are only for giving a consistent load at each setting, a bit of practice will do that.

[Paul Relf-DaviesParticipant @paulrelf-davies37806]

Posted by Gordon W on 22/11/2015 10:39:13:

I would not worry about the ratchet working, they are not essential and we were told not to use them. They are only for giving a consistent load at each setting, a bit of practice will do that.

Indeed…that was my general theory. It would certainly be nice to have it working, even if just for a sense of completion, but I won't let the lack of a functioning ratchet stop me from using it!

P.

[mechman48Participant @mechman48]

I was instructed when serving my apprenticeship…. maaaaaaany moons ago , the ratchet was for consistency initially then after approx 6 mo. you should be sufficiently experienced to measure with 'touchy, feely sensitivity' to achieve your machining / fitting tolerances then ignore the ratshit… Oooops 'ratchet' … the same applied to inside / outside callipers.

George.

[Kiwi BlokeParticipant @kiwibloke62605]

Paul, I don't know how 'assembly paste' compares with CV joint grease, which is pretty special stuff, compared to 'ordinary' moly grease.

Graphogen is a trade name of the graphite-loaded one I have used. The MoS paste I use is Australian, Molybond GA 50. I think Rocol have a similar product, but haven't noticed it in NZ. The GA 50 blurb states: '…containing 50% molybdenum disulphide powder in a lithium based grease used as an anti-seize and anti-scuffing compound for metal parts. It has an extremely high load-carrying capacity and a wide temperature range of -10C to 150C (suitable for use up to 400C as an anti-seize compound). This product does not contain copper, nickel, aluminium or graphite.' So it sounds like the answer to a maiden's prayer, doesn't it? I think its solids content is much higher than (most?) other moly greases. It really is useful for all sorts of things, particularly highly-loaded sliding surfaces of similar metals.

Incidentally, scroll chucks benefit from intelligent lubrication, not just any old oil or grease. Their clamping force can be dramatically increased by using such a lubricant, or a ferociously expensive one, Kluber Altemp Q-Paste NB 50, as specified by a European chuck manufacturer. I had to lie down for a bit, after buying some, years ago. I don't know if it's still available. Worth it though – it goes a long way.

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