Dry Moly Lubricant Spray

During a sort out of my shed I can across a can of Dry Moly Lubricant Spray made by Ambersil. I have used this in the past on worm gear applications and I wondered if anyone had used it for the teeth of change gears on a lathe instead of thick oil or grease?

The data sheet gives open gears as one example of its use, it also states that it will prevent scuffing and reduce friction. It sounds ideal for change gears but I have never seen it mentioned in any of the lathe handbooks or any forums.

Does anyone have any views on its use, I'm just interested to know.

Neil

Well, all lubricants are supposed to prevent scuffing and reduce friction!

Manufacturers' claims are sometimes optimistic ("WD" actually stands for "Water Dispersant", not "Worm Drives" ) but if you've found this lubricant satisfactory on worm-gears I'd think it safe on change-wheels.

I would though suggest being quite thorough with it, because it might not be carried from tooth to tooth as readily as conventional oil.

Neil,

I can’t see it doing any harm:

**LINK**

https://www.farnell.com/datasheets/494125.pdf

but it seems awfully extravagant, at about £20 a can

.

As my Liverpudlian friends used to say:

… Like using a Rolls Royce to kill a pig.

MichaelG.

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P.S. __ The safety data-sheet seems to be all about the hazards that come with it being in spray cans

https://tech-beac.com/sites/default/files/support-document/MSDS-AMBERSIL-DRY-MOLY-400%20ml_0.pdf

Edited By Michael Gilligan on 26/09/2022 05:22:26

[ Sanity Check ]

Molybdenum Disulphide is good stuff

… as a dry powder, it is also relatively cheap: **LINK**

https://lowerfriction.com/dry-solid-lubricant-powders/molybdenum-disulfide-mos2-powder/

How did mankind get into the state of insanity where tiny quantities are sold in expensive and hazardous packages

MichaelG.

I don't know, I have a 1 lb tin of it courtesy of the USAF. They chucked a load out as lifetime expired! I also acquired several large dural billets via the same logic.

regards Marin

Back in the 1980's Myford used to supply a Rocol product, (I think it was MOS, or MS), which was similar to the spray on sort that you have. I have been using for many years Molykote GN paste, comes in a tube and I apply it with an artists broad paint brush to my change wheels.

It does stay put once applied and does not fly everywhere which is what tends to happen with some greases.

Regards

Gray,

I use oil on the change gears. Anything that might stick to them, and cause wear, is either thrown or washed off. I don’t really want grinding paste between my gears.

Sounds good to me, just be careful not to get the stuff on yourself, moly is dirty black stuff.

Surely if you want to lubricate gears use an ep oil and if it flys off you have put too much on. I have something that clears that up it’s called a rag!

I used it a lot back when I was working on part's of plant where I didn't want any contamination from the lubricant, but I never used it on gears

H

Molybdenum Disulphide goes off by oxidising in air. The decay isn't serious enough to worry a light-duty requirement like lubricating change gears, but even mildly cruddy lubricants are best avoided in aircraft!

I guess the USAF's 'use by' date assumes the worst case scenario, such as a can being repeatedly shipped between hot and cold airbases in an unpressurised aircraft, causing the can to breath much more air than it would in a shed.

Dave

These were unopened tins. Good for slideways.

Martin

Michael,

Once again you nearly made me spill my tea.

David

I was MD of a chemical manufacturing company supplying the aerospace industry amongst others. Most of our products, if left unopened in their containers, had an indefinite shelf life. However, some of our customers insisted we gave our products a use-by date. We were happy to comply.

In some cases where product had reached its use by date we would, at the customers request, remove it from their site and replace it with new product. They would be charged for the removal and for the new product. Rather than sending the old product to landfill we would either revalidate and repackage it ready for sale once more or rework it with the next batch of product.

As an accountant by trade I was rather fond of use by dates...

Graham

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An accountant might well see it that way, but the historically the military have had severe problems with suppliers not understanding how their product might be treated in peace-time and no idea about the way stores are abused in war-time! For that reason, the military often call for triple layer packaging or more, with full labelling inside each layer identifying the part by name and stock number, plus relevant information about date packed, shelf-life, hazards etc etc. The packaging may also have a shelf life! Ridiculously extreme by most civilians standards, but it's not done for civilians.

The idea is to make sure the guys being shot at aren't let down by duff spares, whether damaged in transit, poorly stored or by old-age. As this is extremely difficult to get right I strongly suggest it's best for suppliers to meet requirements set by the customer's engineer. Possibly he made a mistake, more likely he knows much more about the product and how it might be used than the supplier.

Martin commented: These were unopened tins, which is fine and dandy except sealed tins leak! Not much, but enough to be a problem if the customer has identified it as an issue. As I said, I don't think using degraded Molybdenum Disulphide on a lathe would matter at all.

I just note that as an inorganic chemical, Molybdenum Disulphide isn't completely stable. Unlike Common Salt it doesn't have an almost unlimited shelf-life.

I think the main problem with use-by dates is they never explain the underlying assumptions. Products stored in favourable conditions often last much longer than the use by date, whilst the same product stored unfavourably is likely to go off rather quickly. But we aren't told what favourable and unfavourable are. So use by dates are guidance rather than exact times, and the value of the guidance depends on our circumstances.

Dave

I made a mistake with the Rocol reference earlier. Having found an old tube of the grease in the workshop yesterday, the correct reference is MTS 1000.

Molykote GN which I mentioned earlier was one of the many greases used to service the Radiotherapy machines or Linear Accelerators which were in the Oncology Workshops care. Being used in close proximity to the beam it never showed any signs of degradation, or drying out. It was never thrown about by the various gears it was used on.

Hence why I started using the same thing on my lathe changewheels.

Regards

Gray,

I was interested to see the comments on the use of the dry moly spray, I'm not sure that at the current price I would buy another can, but you never know. The only thing that has stopped me actually using it on the change gears is the thought of degreasing all those teeth before being able to spraying it on. It needs a clean surface for it to be able to stick successfully.

I might have a go at the gears that are used for the fine feed and see how long it lasts, probably a long term test, otherwise the can will most likely stay on the shelf.

Thanks to everyone for the input, being retired, this forum is now the only place that I have to bounce my thoughts off others and get their opinions.

Neil

I'm kind of wondering if the end product includes sulphuric acid.......
Probably not critical though.

.

I’m not arguing, Dave … I don’t have the knowledge

But if you’re sure of that, you might consider editing its page on Wikipedia:

MichaelG.

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Chemical reactions[edit]

Molybdenum disulfide is stable in air and attacked only by aggressive reagents.