Antiseize for SS watch Case Backs (Copaslip)

[Waggy]

Hello everyone,

I've been working on a few stainless steel (ss) watch cases and I've encountered problems with screwing the case back off and on (even after cleaning). The problem seems to be that the dry threads which may have been abused in the past have that crunchy gritty feel when opening/closing and are difficult to get started. I accidently got a blob of silicone onto the threads (from the o-ring) and noticed that this really helped, so I then tried a very small smear of lithium grease I had kicking about directly to the threads and all the threads I tried it on were smooth as butter. Then I started thinking back to my engineer training days in Sunny Montrose in Scotland and we used copaslip (see below) on the threads of oilfield service tools, and was pondering if this was a better idea for the threads than the lithium grease as this is what it is designed for.

does anyone use anything better or have any better ideas, what do you use, if anything?

 

Edited November 7, 2023 by Waggy
Typo/grammar

[Michael1962]

I am a fitter and machinist by trade and I can tell you that either the above product or nickel anti-seize is all that should be used on a stainless to stainless contact. I have not used the above product, but if is much like nickel anti-seize, an amazingly handy product.Oil does not work for S/S to S/S. Don't ask me how I know, but it involved me near tearing the head off the TA that was 'helping' me on a steam turbine.

A very clean S/S to S/S thread should not cause you any trouble, but if there is damage to a thread, the chance of the S/S 'picking up' can be quite high. If there is pressure between the faces, the risk increases.

You may find that it won't always be necessary. Obviously, the newer the watch, the less of a problem unless some previous repairer was ham-fisted in his treatment.

The only issue would be application and the amount required. It would be a minute amount at best as a little goes a VERY long way. In other words, don't use the brush that comes attached to the lid of the can. 

[Marc]

The process you are describing is called galling and is caused by the transfer of microscopic amounts of material between two sliding metal surfaces, especially if there is a significant contact force between them.

If you Google anti-galling lubricant for stainless steel you will find a plethora of specialised products for preventing galling ranging from reasonably priced to out of this world expensive depending on how demanding the application is.

[Waggy]

@Michael1962 thanks, yes I know that feeling of a thread galling on an Inconel 718 part and costing several tens of thousands of dollars all due to someone skimping on an few pennies worth of copaslip. Now I remember that copaslip was banned in the North Sea after I moved to Canada, never clear why and rumors I heard said it was found to have carcinogenic properties, but this was just hearsay, this is of course after years of me elbow deep in the stuff. I half remember that we switched to a nickel version, I think - it was a while ago! However, seeing that it is still on sale, I now doubt if the stories I heard were true.

I applied the lithium grease with a tooth pick, and just a barely visible thin film, I intend to do the same with the copaslip or nickel version.

Edited November 7, 2023 by Waggy

[Michael1962]

I do use the term 'galling' as well. 'Picking up' is a term that has obvious, immediate significance.

[CYCLOPS]

there is nothing wrong with a little Lub on the threads....Happy New Year

[Waggy]

Quick update, I have been using the Copaslip on my last 10-15 watches, just a tiny amount (1-2 mm^2) applied evenly to the threads of the case back with a tooth pick. And it is making even damaged threads smooth and effortless for closing and re-opening, applying Copaslip is now part of my standard practice for all watches. I decanted a small amount (50 ml) into a small jar, which will last me forever, so the other remaining 450ml in the paint can size tin will be passed on to my son and his son.......