GMT gained 35 minutes overnight!

[Raindance]

My 50-year-old GMT was "overhauled" last winter. Several nights ago it gained 35 minutes in the nine hours it was on my nightstand (face up). I wrote the gain off to my setting it wrong . . . though I didn't recall setting it. Two nights later (without my touching it) it did it again . . . 35ish minute gain overnight.

Does anyone have any idea what's happening?

Thanks,
RD

[Tools]

50 year old GMT............ nice........

A 35 minute speed up overnight might indicate a large magnetic field close by affecting the amplitude of the balance... perhaps a radio controlled clock or cell phone next to it............

It is also possible that it is not fully wound and close to depletion..... when there is not enough energy at the mainspring, the movement becomes erratic, usually speeding up..

[Rikki]

It could also be a positional error. 50 years old the balance staff could have a burr on it and in certain positions cause it to slow the balance wheels amplitude speeding it up. I think you said it was dial up try laying it dial down and see what happens. Let me know Rik the watchmaker

[weizhen77]

Originally Posted by Tools

... A 35 minute speed up overnight might indicate a large magnetic field close by affecting the amplitude of the balance... perhaps a radio controlled clock or cell phone next to it............

I use my cell phone as alarm clock, and it was beside my watch every night.

[padi56]

Originally Posted by weizhen77

I use my cell phone as alarm clock, and it was beside my watch every night.

I would go along with Rik on this one as the two gains were very similar.A watch thats becomes magnetised normally speeds up and runs very erratic or comes to a complete stop.

[Flyer737]

I have my new watch lay face up next to a radio controlled clock and my iphone, Larry are you telling me I shouldn't be doing this, I thought there was some form of magnetic protection in new Rolex or is that just the Milgauss. At the moment my watch is loosing about 3-4 seconds a day ish, any thoughts?

[Flyer737]

Any further info, ref my last comment

[watchmadman]

Britten's watchmaker's dictionary and guide states there are standards set for watches just like cars and electrical appliances, all watches for sale in UK have to meet the British Standard #3637 that a watch is tested in a Magnetic field of 4,800 ampere meters (60 oersteds) in various positions must not stop nor have a residual change in rate exceeding 45 seconds -these are the rules for watches cased to 20mm in diameter. (larger watch rules are not supplied) I imagine a mobile phone does not produce as much as that test rateing, I keep a compas with my demagnetiser to test for magnetism and a quick test on my mobile shows there is a field present but not a strong one, I think it would peak when recieving calls though.
I am with Ric on the Balance wear being the culprit with the original watch question, has the author removed the appliances and found the watch to run perfecly in the same position?
As to watches being highly susceptable to magnetic fields I think all countries will have similar STANDARDS to the UK and therefore your watch should not be affected- believe it or not I had a lot of trouble with a watch gaining time at night and running fine at day, couldn't figure it at all- I had just serviced it and was most unhappy with things- turned out to be the temperature affecting the oil I had used, bedroom was Airconditioned and cool, I put the watch on the side table to sleep- oil got cold and changed it's viscosity then back on my wrist it warmed up. Changed the oil for a synthetic and she's running like a charm.

[padi56]

Originally Posted by Flyer737

I have my new watch lay face up next to a radio controlled clock and my iphone, Larry are you telling me I shouldn't be doing this, I thought there was some form of magnetic protection in new Rolex or is that just the Milgauss. At the moment my watch is loosing about 3-4 seconds a day ish, any thoughts?

Then you have nothing to worry about first signs of a watch becoming magnetised.Normally speed up by lot more that a couple of seconds and run very very erratic or come to a complete stop.Most Swiss watches including Rolex have to pass the Swiss standard for anti-magnetic watches.Which is to withstand a strong magnetic field of 4800 Amps per meter,and to keeps on running with a maximum deviation of 15- 30 seconds per day.Now this test I am 100% sure that 99% of all watch wearers would never subject or come into contact with such a strong magnetic field.

[jrbar-on]

An easy to check if your watch is magnetized is to hold it over a compass and then move the watch slowly and note if the needle moves. If the needle follows the watches movement then it is a sure sign that the watch is magnetized. This happened to me once with a Blancpain Aqua Lung and I used my son’s toy compass to determine if the watch was magnetized. It was and I took it to my watch maker who zapped it with a degauss machine and it was fine.

Jonathan.

[Rikki]

The compass method works on some models but the ladies 2030 cal has a permanent magnet breaking system for the sweep second hand. Rik the watchmaker

[mike]

Originally Posted by Raindance

My 50-year-old GMT was "overhauled" last winter. Several nights ago it gained 35 minutes in the nine hours it was on my nightstand (face up). I wrote the gain off to my setting it wrong . . . though I didn't recall setting it. Two nights later (without my touching it) it did it again . . . 35ish minute gain overnight.

Does anyone have any idea what's happening?

Thanks,
RD

Welcome.

The watchmakers have given great advise. Heck, please post a photo when you can. As a fan of the GMT I'd love to see it.

[Raindance]

Thanks, Guys. I'm in search of a compass.

FYI, the time-keeping capability of the watch is erratic . . . checking the watch over the last three evening showed . . . it lost 45 seconds in 24 hours, gained 67 seconds in the next 24 hours, and lost 159 seconds the next 24 hours.

Thanks for the help.

RD

[rsmithor]

Interesting points... the compass to see if the rolex ever magnetized. i have a hand held electric degauss device for my old tape deck heads... seems that would work if i ever got in that situation...

[Rikki]

Part of any service is to demagnatize the watch before timing can begin. The class i took lsat week at least half of the class watches we were working on were partially of fully magnatized. We use a push button demagnatizer. People that work with mri and catscan machines are good customers their watches come it locked up. anywho Rikki

[Raindance]

Well, I finally gave up and sent the watch back to my favorite jeweler. He didn't want it running erratically either.

Thanks for all the help. I'll keep ya'll posted on how it turns out.

And, Mike . . . I don't have an "up close" picture of the watch. Sorry.

[Tylden Reed]

It is possible that the mainspring as fully wound and the slipping mechanism within the barrel too tight. Too much power and laying dial up will cause the balance to 'kick'. The amplitude of the balance will be excessive and cause it to bounce from one extreme to the other thus gaining excessively. Hope this helps. T.R.

[Tylden Reed]

Sorry. "It is possible that the mainspring as" above should have been: It is possible that the mainspring was.

Following my suggestion I had hoped for comments from you!

I must say that the general standard of illustrations on the Rolex Forum is excellent. The information available is outstanding. It only goes to prove that no matter how long you have been doing something there is always more to learn. Tylden.

[Rikki]

The common term for over amplitude is galloping because that's sort of what it sounds like. It is possible but not as common as the other maladies,plus you can hear it as well which should rule it out quickly, but good call glad to see someone out there thinking. Rikki

[Tylden Reed]

Hi Rikki.
Yes I agree with you, you would probably hear the galloping but not if you were asleep in bed at the time! The fact is that it seems that there was no problem before the service so unless something with a heavy magnetic field was placed near the watch at that time it was more likely to be galloping.
I would check for magnetism first and de-mag anyway. Then check the lubrication of the barrel/mainspring. My guess is that the barrel wall was either not lubricated or (less likely) lubricated with the wrong lubricant, either way the effect could be the bridle /slipping attachment is not slipping as it should with the obvious results.
Having had the watch back once I would check the lubricant as well. The last thing I would want is for the customer to send it back again. We are all human though!!
Working alone I rarely get to converse with others at the bench so it good for me to chat with you. Thanks.
Best regards,

Tylden.

(Tylden Reed. F.B.H.I.)
Tylden.

[Rikki]

Absolutely the mainspring could be causing the problem from a lubrication standpoint. Other things are that someone could have put a standard mainspring in instead of the weak spring, there's so many little things it could be the best is to start from the beginning and check it all from lubrication to balance pivots gear pivots end shakes side shakes and on and on and on. As you know typically a watch that has been magnatized will gain considerably more that 35 seconds it's usually gaining hours with in hours,but you have to start somewhere I guess. Nice to talk with you Rik