Stubborn Crown

[rustycolt]

Good day all. 

I was working on a lovely Bulova auto this past weekend. The original complaint was that the crown was VERY stiff - difficult to turn for winding/setting, and difficult to pull out into the setting/date change positions. A cursory inspection revealed that the watch was well overdue for service, so I opted for a full disassembly, cleaning, and re-oiling. This would give me an opportunity to closely inspect the train and the keyless work, where I felt the problem was most likely to originate.

 

No unexpected problems were found, and the service went well. Upon completion, the watch was running beautifully, winding and setting were smooth and silky. 

 

Corks were popped, champagne was drunk, celebrations abounded. 

 

...not so fast. 

 

I let the watch run for 24+, as I like to do before casing. It went well, so I was keen to close everything up and pat myself firmly on the back. When the time came to re-install the stem, I learned that the problem had not, in fact, been completely eliminated. The final few mm of push to seat the crown had a fair bit of resistance. First thoughts were bent stem, interference with the tube, something along those lines. I removed the movement and confirmed that everything operated correctly out of the case. Inspection of the stem and tube revealed no anomalies or misalignments. I then installed the stem into the empty case, and discovered that whatever the problem, it was the relationship between these two parts that was at it's root.

 

That point marked the end of watch time for the day, and I had to walk away in favour of other pursuits. 

 

Today, during the course of my daily routine, my mind seems to have this task running in the background, and it is using its spare cycles to work this seemingly simple problem. There must be some dirt/gunk/old stem gasket inside of the crown that is interfering with the tube when it is inserted. I'll investigate this evening. 

 

I'm not sure this is even a post-worthy issue. Not particularly interesting or difficult. I think I just needed to put it down to settle my wandering mind. Having said that, even the simplest problem can sometimes be caused by strange or unusual phenomenon which are only visible to the experienced eye. With that in mind, perhaps some sage advice may emerge from one possessing greater wisdom than I.

 

I'll post back after I remove, inspect, and clean the crown cavity.  I know you will all be on the edges of your collective seats until then.

 

I'll post a couple of my preliminary photos as a reward for any of you who bothered to read this far.

 

 

 

[Geo]

I've just moved to the edge of my seat in anticipation! :-)

[anilv]

probably the rubber inside the crown has gone hard...

 

Anil

[bobm12]

 

I've just moved to the edge of my seat in anticipation! :-)

Me too! :)

 

I had a similar issue and it was the movement ring interfiering with the stem...I don't think this is case here though...(?)

 

Cheers,

 

Bob

[rustycolt]

I can't leave you guys in suspense. I'd hate to be responsible for any cardiac events as a result of the anticipation...

 

...or tipped over chairs.

 

BTW, the case and crystal both polished up nicely:

 

 

The problem was the crown o-ring.

It wasn't even damaged, just neglected. 

This 40(ish)yo watch has definitely missed a service interval or two. As a result, the crown gasket had probably never been lubed. Now, I know full well the value of adequate lube, but I did not expect the near seizure of the crown the way this was. A tiny smidge of silicone, and hey presto! Works like day one. I replaced it all the same.

 

It regulated superbly, and will serve well for another decade or so. 

 

THE MORAL OF THE STORY:

Watches are complicated and precise bits of machinery. The faults which cripple them are (usually) not. As in most troubleshooting process, always focus on the simplest causes first, instead of assuming that the problem is as convoluted as your imagination is trying to make it out to be.

 

-Jeremy

 

[Geo]

Great result Jeremy, and good call Anil.

[WillFly]

Excellent posts and a good result. When I see guys on other watch forums boasting about how they've been running a watch for 40 years with no problem, or complaining that they can't afford to get a good watch cleaned, I think to myself, "Just you wait...!"

 

A good, regular service for a well-used watch makes good common sense, IMHO.

[Mark]

A few weeks ago I was working on a Seiko automatic chronograph and the pushers were not working at all.

 

I took them out and the o rings were solid like bakelite. I literally had to chisel them off and they broke up into pieces. That watch must have been over 30 years old and I am pretty sure the o rings had never been changed.

[anilv]

If the rubber is hard like a rock.. its bad, but believe me..o-rings and gaskets that get soft and gooey are far worse..its a pain getting it clean and on some watches it can affect the dial as well (theres a blog which decribes this issue on a Heuer Monaco!).

 

It smells bad and I think contact with skin is not advised.

 

Anil

[Mark]

Just done an omega chronostop with the gasket like tar. Came off with an old rag and lighter fluid. Very messy though.

Sent from my iPhone using Tapatalk

[Geo]

Ditto an Omega Marine Chronometer, a real sticky mess.

[rustycolt]

So, the lesson I have learned here, and has which been overlooked in any book or educational material that I have seen thus far: Maintenance of the case sealing components is as critical to a proper functioning watch as any of the work that goes on inside the case, and not just for reasons of preventing ingress of moisture and dust. It's quite obvious looking at it now, but something that seldom receives a second thought when all you do is move your watch from wrist to nightstand and back again.

 

My new question is, what is causing these failures? Rubber itself, is inherently a very stable material. I can understand drying over time, leading to swelling, cracking, and compromised integrity. That is pretty normal behaviour for rubber. What time does not account for is the symptom which several have described here - the softening or liquefaction of old rings. There must be a catalyst at work here, and I'm curious about what it may be. I have two culprits in mind:

1. Owner exposure through wear- Use of the watch in chlorinated swimming pools or salt water without a clean, fresh water rinse afterward

                                                     -Environmental lifestyle factors like working in a kitchen for a living or cleaning/mechanical work which could expose the watch to chemicals

The stem is the most likely place for foreign material to collect, being difficult to clean (from an owner's perspective) as well as exposure to the elements, so the failure of this particular ring in this fashion would support this theory. 

 

2. Dodgy workmanship - If improper lubricant is used on a rubber ring such as this, the chemistry of the rubber will change, leading to the kinds of messes which do not belong in Omegas, and are not joyful situations to remedy.

 

This lesson makes me a better watch owner, as I can use my new found awareness to improve my care and maintenance. It also makes me a better craftsman, as I can see the outcome of improper practice and apply that knowledge to effect correct technique. Win/Win.

 

...there is a third theory floating around out there which is based on the idea that Goodyear is manipulating the material in order to increase the world's dependancy on rubber by forcing watch owners to replace their o-rings once every 15 years or so.  :ph34r: I'd say more, but everyone who talks about it seems to disappear shortly afterwards, never to be heard from again. 

 

[anilv]

Once sealed at the factory...its good until someone messes with it.

Crystal seal, crown seals, caseback seals. The one weak point is the crown... If you have to wind it or periodically set it then the crown seal will wear.

Seiko did the smart thing and did away with hand winding.... If its run flat you have to shake it. You only need to pull the crown and set the date/ time. The crown seal gets an easy life.

Anil

[frenchie]

Very nice write up. Thanks for sharing. I have yet to work on a watch with a gasket like this, but I'll keep that in mind !

[bobm12]

Thanks for sharing! Very informative thread!