Molybdenum based grease - please don't use!

[Ivor-Duncombe]

I have noticed that there are members who use and recommend the use of molybdenum grease as a mainspring lubricant. My experience has taught me that a light modern mineral wheel bearing grease is as good a replacement as one can buy for the lubrication of any gramophone or talking machine mainspring.

Molybdenum CV joint grease is relatively expensive and VERY messy. More than this, it just performs too well to be used for lubrication of coiled flat springs!

What I have to say is that molybdenum grease adheres so well to the surfaces of flat springs and has such surface tension that it can "weld" the coils of tensioned flat springs together. Here the term "weld" describes the type of bonding that arises between surfaces of flat springs that are wound up against one another hard enough to drive excess lubricant from between the spring coils. It is this type of welding that is used to advertise two-part epoxy glue. Two small polished plates of flat metal are bonded together under pressure using the epoxy glue and the glued joint is shown to be able to support the weight of a medium-sized pick-up truck. The strength in the weld arises from the fact that air cannot penetrate the glue between the metal plates used in the advertisement. Cavitation does not readily occur in the molybdenum grease between inner and outer sides of flat spring surfaces to release the turns of the spring from one another smoothly as the spring runs down.

When a gramophone, talking machine or even a clock motor spring is lubricated with a molybdenum grease one may often hear:-

i) the motor losing speed slightly (or not at all),

ii) i)followed by a slithering sound as tension comes off the turns of the spring that have suddenly been released from one another more suddenly and less evenly than they should, (then motor speed recovers)

iii) or i) followed by a "thud" (or even a "bang") when bonded spring turns are released even more too suddenly than should happen (then motor speed recovers - or not!)

Occasionally, however, the bang or thud will be followed by a ringing ripping sound as a large series of adjacent gear teeth are flattened or ripped off a gear in the motor drive chain (usually) where a large gear engages with a smaller gear or pinion.

This last sound is one that no talking machine owner ever wants to hear from his or her precious gramophone or talking machine (not once, not ever). It is an expensive and saddening sound.

The slithering and bumping sounds I have heard fairly often and they do always result in some sort of cumulative damage. I have only heard the bang-zip sound once and I never want to hear it again.

If you have used molybdenum grease to lubricate a motor spring, then please reconsider. Safe and enjoyable listening for all.

Regards, Owen

[De Soto Frank]

Wow.

So... back to equal parts Vaseline & Dixon's #2 flake graphite ?

[Lucius1958]

Is white lithium still OK?

Bill

[VintageTechnologies]

Is white lithium still OK?

Bill

I have heard that white lithium will dry out. I packed an Edison Home spring five years ago with white lithium and it has run great ever since. Some people add a bit of heavy oil with the white lithium.

I have also used the black moly lithium on a few machines and have yet to notice any of the ill effects that Owen describes. I will be monitoring my machines and this post with heightened interest.

By the way, I don't find the black moly grease to that nasty or hard to clean. On the other hand, Vaseline/graphite is by far the nastiest stuff I've dealt with.

[Ivor-Duncombe]

To Bill and De Soto Frank,

I'm afraid that I have no personal experience with your greases. I'm sure that, with time you have both found what works best for you. I might well have removed and replaced greases and grease blends similar to what you use when I've serviced or repaired motors for other people. And your greases may even work better than the wheel bearing grease that I use. Is your white lithium the grease that I've seen used in plastic-bodied electric drills? If so, then they do seem to dry out with time.


I can only say, however, that springs in machines that I serviced 20 to 25 years ago with my favourite Castrol wheel bearing grease, and the few that I have serviced again since then, then are still running well.

I went through a phase when I lubricated my own motor springs with CV joint grease and ended up stripping my HMV 102 motor (intermediate drive gear and turntable shaft pinion gear teeth). I'd been hearing the slithering and bumping for some time before it happened. Three of my other gramophone motors had been making similar sounds but I flushed and re-greased the springs and drums of these (1 Columbia, 1 HMV No. 32 and one Garrard No. 20) before they incurred similar serious damage.

The CV joint grease that I used was supplied in a plastic tube by Volkswagen for VW and Audi use. I find that this grey-black grease is very messy and seems to get around a lot (under finger nails, onto the work-bench and onto clothes etc. - maybe I just get too involved in the work I'm doing!)

As long as your motors aren't making slithering, bumping or banging sounds, I'm happy. Vaseline seems to me to have too low a melting point where it almost becomes an oil which feels as though is not a very effective or protective lubricant - maybe adding graphite to it helps a bit.

Regards, Owen.

[Player-Tone]

Oh no, it looks like I will be re-rebuilding one of my phonographs this summer.

I used moly grease 'Mobile 1 synthetic' in the spring barrel on my VV-50 (thankfully it's just a single spring). -I found that the motor runs fine, but when winding it up you can hear the spring peeling off the barrel as it moves towards the center (slithery sound). Then again the spring is moving very fast when being wound up and very slow when unwinding, allowing time for it to peel off smoothly. Does that also happen with other greases?

[need4art]

I don't get it... I have used Mobil 1 synthetic bearing grease on 5 machines-1 4 years ago and no problems no matter how tight I wind up the spring.
Abe

[Player-Tone]

I wonder if not all moly grease is equal- maybe Mobile 1 synthetic is an exception?

[De Soto Frank]

Owen,

The mixture of Vaseline and Graphite I was referring to was Victor Talking Machine's recommended "grease" back in their hey-day... and as Vintage Technologies mentioned, once the volatile compounds have evaporated, the stuff is very difficult to remove... it's almost like soft coal.

I have not re-greased any springs for a number of years... the last was in a VV-XI, and I used Sta-Lube black graphite grease, which is a moly grease, fairly soft... it seems to work well enough ( no "slithering or bumping" ), but it has a fairly strong petroleum odor, that is rather disagreeable when you raise the lid of an otherwise very nice machine...

I'm curious whether your favourite Castrol "wheel bearing grease" is a fairly heavy, stiff grease, deep amber in color, and translucent, such as was common oh, about 50 years ago and earlier ? It has a consistency somewhat like jam, and was tacky enough to be useful in holding loose needle or ball bearings in their race while assembling machinery.

The Sta-Lube stuff I used was softer and smoother, about the consistency and texture of sour cream...

[Emgian]

Well that is a very interesting and strongly put opinion, but may I make several quick observations?:
1. Were the springs cleaned thoroughly to remove the hardened graphite particles that really do bind to the spring leaves? If not scraped off with a knife manually, then polished off with wire wool, followed by a thorough rinse in spirit, these patches of strongly bonded graphite WILL bind with each other as the spring leaves pass each other and the patches coincide, causing the frightening "bump" we all dread, regardless of what type of new grease applied! So a thoroughly cleaned spring is essential as a starting point for this discussion...
2. In my experience, wheel bearing grease is
probably a little stiffer than basic light motor grease if you wish to avoid the high tech lubricants.
3. All greases have a limited optimum life, and tend to increase friction as the lubricant evaporates.
4. I did a little research on Lithium based Molybdenum Disulfide grease, when looking for an alternative to graphite grease, (which was always a real pain for getting transferred to the floor) about ten years ago,and discovered that it claimed to coat the bearing surfaces with a protective film, whilst the medium containing micron sized solid particles that acted like thousands of miniature ball bearings to allow, in our case, the spring leaves to glide past each other almost friction free and NOT binding together... I was impressed with the theory, and have used it for ten years, not only with my own motors, but many others without ill effect that I can determine. I tried to find the original specs but couldn't, however the first industry web site I visited came up with the basic " lubricant with micron-size particles that work like thousands of tiny ball bearings to dramatically reduce friction and wear. ... Micronized molybdenumdisulfide. lithium complex grease with excellent low temperature properties." extracted from: http://www.zep.com/product_Catalog/Oil%20and%20Gas%20Catalog.pdf
I would pose the question: If this Moly grease was responsible for binding spring leaves together, would it ever have been allowed to be marketed for such widespread use in critical CV joint lubrication? It is more favored and generally replaced graphite grease for that application.
I am no expert on the structures of grease, and am fully open to a solid proof that my own faith in molygrease is misplaced, but in the meantime, I will happily carrying on winding up my EMGs with one ear cocked for the "Bump"!
To see how seriously enthusiasts in other interests take their greases have a look at this:

http://www.bikeforums.net/bicycle-mechanics/637749-molybdenum-vs-lithium-based-grease.html