It will evaporate whether in use or not. I don't know about congeal

 

Can't image it being as much of an issue nowadays with the better synthetic lubricants available.

 

It’s a minefield, wear it every day and you wear it out, never wear and it seizes up.

I suppose the 99.99% of the normal watch wearing public would ask the question….. why would you buy a watch and then not wear it?

 

From what I've read, modern synthetic oils are not as prone to drying up/congealing. That being said, I would think that it's still good to get a movement up and running every so often.

I think the better question is... do you really need to hang on to all those watches? If you have over 30 watches that aren't in the regular rotation, I doubt that many of those will ever break back into the rotation. At the very least, you should sell the watches that have no chance of being worn on a regular basis.

 

I think the better question is... do you really need to hang on to all those watches? If you have over 30 watches that aren't in the regular rotation, I doubt that many of those will ever break back into the rotation. At the very least, you should sell the watches that have no chance of being worn on a regular basis.

Sez you. Your personal collecting philosophy is just that.

 

I’ve gotten the impression that people in the know are on both sides of this issue. It makes me feel like it’s not really something worth worrying about. Whether you wear it or not, and some point you’ll pick it up and the performance won’t be good, and then it will be time for a service.

 

Wear occurs during use
Time degrades seals and oils even when not used
For me however it does not matter
I have few enough watches that they all get wrist time
And service is not a consideration as long as a watch works within my expectations.
I’m not saying anyone else should but I don’t follow recommend service intervals

 

Modern synthetic oils don't really "congeal", they just dry up completely and leave a dry residue behind, like this:



The older natural oils would certainly congeal, so the lighter elements evaporate first, leaving behind the heavier elements in the oil - that looks like this:





This residue is very sticky, and can actually become quite firm over time - here's a balance jewel in a watch and in this case the oil has migrated to one side:



That oil is not liquid anymore, so when I took it apart, it was self supporting:



These older natural oils would break down quicker than modern synthetics, and the gummy nature of them would actually stop the watch. This is sort of a good thing, as it prevents damage from running the watch when the oils are gone. Modern synthetics just let the watch run and run - this is why performance of the watch is not a good indicator that everything is fine inside.

There may have been a point in keeping a watch running with the older natural oils, because they are less likely to size up over time as the oils degrade. This is likely where this idea comes from, but natural oils aren't used anymore (at least not by professional watchmakers - there may be hobbyists who use them as they are much cheaper than synthetics) so there' s no reason to keep a watch running, or to wind it every so often, etc.

Cheers, Al

 

Modern synthetic oils don't really "congeal", they just dry up completely and leave a dry residue behind, like this:



The older natural oils would certainly congeal, so the lighter elements evaporate first, leaving behind the heavier elements in the oil - that looks like this:





This residue is very sticky, and can actually become quite firm over time - here's a balance jewel in a watch and in this case the oil has migrated to one side:



That oil is not liquid anymore, so when I took it apart, it was self supporting:



These older natural oils would break down quicker than modern synthetics, and the gummy nature of them would actually stop the watch. This is sort of a good thing, as it prevents damage from running the watch when the oils are gone. Modern synthetics just let the watch run and run - this is why performance of the watch is not a good indicator that everything is fine inside.

There may have been a point in keeping a watch running with the older natural oils, because they are less likely to size up over time as the oils degrade. This is likely where this idea comes from, but natural oils aren't used anymore (at least not by professional watchmakers - there may be hobbyists who use them as they are much cheaper than synthetics) so there' s no reason to keep a watch running, or to wind it every so often, etc.

Cheers, Al

wow thank you so much for this!!!!!! I didn't know any of these before!!

 

I don't think it's much of an issue.
I got one NOS manual wind watch from 1982 and I it hasn't been worn for about 40 years, it just sat in it's box. I wound it and put it on my wrist and still it keeps perfect time (+2 spd) consistently.
If there was a problem with oils drying up or degraded, I believe the first thing it should have caused was imperfect timing of the watch.

 

If there was a problem with oils drying up or degraded, I believe the first thing it should have caused was imperfect timing of the watch.

That's not how it works, unfortunately. The oils drying up will cause a loss of balance amplitude, and depending on how well the specific movement deals with isochronism, it may not make much difference at all to the timekeeping.

Just to illustrate, this is the 1971 Speedmaster I'm wearing right now, but when I first bought it:



It had no service history, so I fully wound it, and performed timing checks over 6 positions, at full wind - these are the results:



So the Delta at the red arrow is the difference between the fastest and slowest positions. At 5.4 seconds, this exceeds the requirements for COSC and METAS watches. The average daily rate is 3.7 seconds, so if I were to just go by this, the watch is running fine - amplitude is a little low, but the rest is perfectly fine.

So I opened it up to take a look at the condition of the movement. The jewels were all dry - no oil here:



Here in the third wheel jewel, you can more clearly see that the oil is dry:



When I serviced the watch, all the jewels were completely dry. So a watch that is dry can not only run, but run well. Timekeeping is not a reliable indicator of the condition of the movement. Having timekeeping problems can certainly tell you that something is wrong, but the absence of timekeeping problems doesn't tell you that everything is right.

Cheers, Al

 

Back in the days of mink oil... used to be a real problem. Nothing makes a watch run better than boiled down mink though. 💡

 

Some of the vintage pocket watches I work on have been very gummed up. Not so much for the newer wristwatches I work on, but a few. Like others have said the newer synthetic oils are much less prone to gelling. Dirt however, when it gets into a watch can be very debilitating to the movement new or old.

mileage may vary.

 

You have to consider that almost all pocket watches were not sealed as well as newer watches. Dust dirt and debris accounts for much of the sticky goo you find on and around these old pivots and jewels.

 

This is very interesting information - thanks to everyone's comments.

 

i'm sure it's a function of time - the longer a watch sits idle, the more likely that the internal lubrication is to cease performing as desired/expected. However, I suspect that with modern lubricants, that interval might be quite long - years - and that lubricant is much more likely to stop working as expected due to regular use as opposed to sitting dormant.

I checked, and recommended service intervals vary. Seiko and Citizen, 2-3 years - if nothing else, to replace the seals; Certina, 3-4 years; Tissot and Oris, 3-5, though the service interval on the Oris Cal. 400 is 10 years; Omega Seamaster, 5-8 years; Rolex Submariner, 5-10 years (guidance changed about 6 years ago to 10); Cartier, 5 years.

Considering the length of these intervals, servicing almost certainly means fresh lubrication and seals. Some manufacturers say service intervals can be longer if the watch isn't worn/wound as much (a few times a month or less), which suggests lubrication is more likely to break down from consistent use than 'gum up' due to less frequent use. seems to me the calculus might be different for a vintage watch or a watch that hasn't been worn or wound at all in a number of years, but i don't have any experience to back up that hunch.

 

I am not sure if and how they lubricated old Seiko 5 watches, but I have a 32yo piece that was not worn for at least 20-25 years. Recently I "shuffled it up" and it ran pretty accurately for a few days.

 

I don't know about watch lubricants but with motor oil we are advised to do an oil change at least once a year even on a car that's hardly driven as the oil (either natural or synthetic) may turn acidic over time, enough to possibly cause internal corrosion.

 

This is due to contaminants from combustion - not a concern unless you are lighting your watch on fire.

 

I have inherited this 20mm ladies' Rado that I don't intend to wear. Seeing as it most likely hasn't had a service in 50 years, I've tried to not let it run at all. The slightest movement of my watch box is enough to power it for a couple of minutes though.
I'm taking it to a local watchmaker on Friday for maintenance and a new crystal (this one is quite yellow). I was thinking about keeping it in storage afterwards, and letting my kids or grandkids inherit it.

So basically the best way is to not ever wind it and just attach a note that it needs to be serviced if found after 2030?

 

Great photos and detailed information, Archer.
Thank you for passing along this knowledge for all to see. (Should be a "sticky", so to speak?) Heh,

 

It was a problem back when I was a lad (think dinosaurs roaming the earth) but not now with modern lubricants.

 

Below is a handy summary and paraphrase of Archer's information about oils:

Natural oils are not used anymore, so there is no reason to keep a watch running by winding it every so often to prevent synthetic oils from congealing and stopping a watch, as was the case with natural oils. Synthetic oils do not congeal, they just dry up completely, and leave a dry residue behind. Though this does not stop a watch running, it will affect its time-keeping eventually. By the time this is noticeable, the damage to the movement of the watch will have already been done.

Synthetic oils have been around for decades. There are references to them in watch technical manual in the 1970's. How long synthetic oils lasts will depend on the temperature a watch is exposed to. The warmer the temperature, the quicker the oils will dry up; the lower the temperature the slower the oils will dry up. So a watch that is constantly worn, will be exposed to warmer temperatures more often than a watch that is seldom worn.

 

Just one more question for Archer.

When a watch's oil dries up, how long would it take for the internal parts of the watch (cogs, wheels, springs, jewels etc) to become damaged if not oiled again?

 

Just one more question for Archer.

When a watch's oil dries up, how long would it take for the internal parts of the watch (cogs, wheels, springs, jewels etc) to become damaged if not oiled again?

That will depend a great deal on the quality of the parts...difficult to say with any certainty.

Sorry for all these questions, but here's another one.

I hear oils have expiry dates. What does this mean? Is it for the time the oil dries up, or for something else?

Oils come with a shelf life, and need to be stored properly - cool dark place. Over time they will oxidize, so that's why they have an expiry date on them.

 

Does anyone know what sort of oils Seiko, Orient, Citizen etc use on their watches? Or do these companies use a variety of them?

 

Seiko Technical Guides state Seiko and/or Moebius oils/greases

 

Sorry for all these questions, but here's another one.

I hear oils have expiry dates. What does this mean? Is it for the time the oil dries up, or for something else?

 

So the expiry date is only to do with the life of the oil in the bottle and not once it has been put in the watch? If so, how does that work? Why the difference?

 

Yes - it's to ensure that you don't put old oil into the watch, which would shorten the life of the oil once in the watch...

 

Hi @Archer

One follow up question. So we have established that watches using modern oils/lubricants in regular use/in a winder will “consume” faster than a watch in a safe.

however, is there a period where watches that are unused (ie in a safe) should be wound and let run down? I ask this as most of my higher end pieces i do not usually wear regularly. Only during occasions, sometimes months in between

 

Periodic winding isn't needed, but if you want to do it once every 6 months or something, it's not enough wear to hurt anything.

 

I would say as long as the watch is a decent quality manufacture, you have owned it without opening it up too much and tinkering with it, and keep it in a good environment (not too hot or cold, room office temperature, moderate in how you wear it, not swimming in it regularly or other activities that would wear it down, etc), i think a watch can go perhaps a decade or more without service and be fine. Yes there will be your standard deviation and ymmv.

 

In the fuze business, we used sperm whale oil, then when that went away, we used a product call Anderall. Both would stay viscous down to -65F.