Vintage Watches : Service or Not ?

[Dan S]

Maybe turning the crown occasionally might keep the seal from hardening around the stem and sticking.

 

[Archer]

pdxleaf

Knowing that lubricants will dry out over time, my thought was that moving the parts through the lubricant would 'stir' them or prolong their life, as opposed to allowing them to sit and 'coagulate'.

Oil evaporation rates are not governed by the air boundary layer, as it would be with water. Oils are diffusion regulated in how they evaporate. So this means for example that when water is evaporating, increasing the wind moving across its surface will increase the evaporation rate - this is not really true for oils. The evaporation rate for oils is tied more closely to mass, which I'll get into more in a minute...

pdxleaf

Given two jars of watch lubricant, would the being used/stirred last longer than one that is allowed to sit for five years?

I will admit this is not an experiment I've done, or have heard of anyone doing. But if you want an answer I’ll get back to you on that...in 5 years...

pdxleaf

Since watches generally require service every 5 years, is 5 years the theoretical limit of the life of a lubricant? Or is there any hope for the future development of 'super' lubricants that might extend the service life of a vintage watch?

No, 5 years isn’t the theoretical limit. Oils inside watches can last much longer, but it depends on a number of factors. For example on some movements the design of the jewels has an impact on the life of the oils. If the jewel is quite small in relation to the pivot size, the oil is likely to dry out there before other jewels, just because there’s less oil there to begin with (the mass I talked about earlier).

Here's an example using an ETA 2824-2. This is the upper third wheel jewel at the red arrow:



Now let's look at the lower third wheel jewel:



It is much smaller in terms of the oil reservoir, and as such I will often find this specific pivot worn in this caliber, while the others are fine - even the upper pivot of the same wheel.

Same thing in the ETA 2892A2 - the upper jewel:



The lower jewel:



I'm just an engineer/watchmaker. I'm not a tribologist, so I'm not on the forefront of research into lubricants for watches. I just use what the brands suggest, and what I know works. The search for the perfect oil goes back a long ways - no one has gotten there yet, but I'm sure they are still trying.

Hope this helps.

Cheers, Al

 

[Archer]

Tony C.

I don't recall, in the case of those that were repaired. I appreciate your insights into the lubricants, and agree that the car analogy is likely influencing the perception that mechanical watches should be treated similarly. But it seems more than counter-intuitive to me that occasionally winding a watch that would otherwise sit dormant for years (or decades) wouldn't confer at least some advantages.

Indeed - this is what makes this particular myth so difficult to bust...

But what I can tell you for sure, is if you let watches sit for decades, the oils will dry out. Running them at this point is doing them no good - it would only have a possible downside.

Tony C.

Might the gears not benefit from an occasional re-positioning? The hands? The crown?

I know of no benefit from occasionally repositioning gears, hands, or a crown. If you can offer reasoning why it would be beneficial, I'm all ears. As always, I'm willing to listen to any well-reasoned argument on a technical question.

Tony C.

You mentioned grease, and I defer to your knowledge of such details, but doesn't it (like other oils) congeal when cooled to a certain degree? And if so, might watches kept in relatively cool storage not benefit from occasional winding?

If the watch is not running, no wear is occurring, so if the lubricants "congeal" when cooled or not, is irrelevant. Unless you are putting your watches in the freezer, and trying to use them when they are still frozen, I don't really see what the concern is.

Moebius 9010's temperature range is -30C to +70C according to their technical documentation.

For 9104, it's -25C to +100C.

For 9415, it's -30C to +80C

For 9504, it's -20C to +100C

Those are the 4 primary lubricants I would use on every watch I service. Sure, the viscosity will increase when it's colder, which could possibly affect timekeeping, but the premise here is about preserving the movement. It would have no effect at all on that.

Cheers, Al

 

[Archer]

Dan S

Maybe turning the crown occasionally might keep the seal from hardening around the stem and sticking.

Hardening and sticking are two different issues. The nitrile seals used in most watches will vulcanize naturally over time - that will cause them to become hard, regardless if they are used or not. I see hardened seals in watches that are not used for long periods, and watches that are used regularly. Temperature is more of a factor here than use, because if the crown is being turned or not doesn't really affect the amount of compression the crown seal is under - that is constant once it's on the case tube.

Of course turning the crown will cause friction between the case tube and the seal - this is why crown seals are lubricated with grease. I use Fomblin UT-18 silicone grease. Over time with use, the grease will get used up, so if you turn the crown when that has happened, you will cause more wear with the seal and case tube. This isn't an issue related to winding or not winding, but simply regular maintenance and replenishing of that grease.

 

[Danwales]

I concur with this. My collection is pretty modest by OF standards ( about 15 watches) and I probably only wear 4 of these regularly. I have had these serviced. The others I don't often wear though all keep decent time.

 

[RoadRunner73]

Well I haven't been into vintage watches for long, but I've taken quite some of my time trying to "catch up" by reading as much as possible this winter ; came across Desmond's Blog about Constellation watches, and one of the many articles he wrote in the early 2000s is referring to Archer's excellent article on "service or not" which I grabbed a few days after I had started this post

It is vastly documented, and probably you'll find it as exciting and clear and convincing as I did !
Here it goes :
http://omega-constellation-collectors.blogspot.com/2012/12/how-often-should-you-service-your.html