Watch servicing question for our watchmakers (and the technically minded)

[learningtofly]

If a movement was disassembled, fully serviced, assembled again and then fully tested, and then the mainspring broke, what would need to be done after replacing the mainspring such that the watch was in a fit state to return to the customer?

Asking for a friend.

[walkerwek1958]

Depends on the watch. Swapping the mainspring on an ETA 2824 or similar is straightforward, barrel bridge comes off, barrel comes out, train wheels and escapement don't get disturbed. If it's a Valjoux 7750, Omega 1861, Miyota 9015, the barrel is buried in the bowels of the movement so a lot of dismantling is required to get to it and reassembly could potentially affect the lubrication. Likewise a Zenith El Primero. On a vintage Omega 565 or 601 the spring barrel can be removed without fully stripping the movement but a fair degree of skill and care is required.

That's from the horses mouth, there's no simple answer. Not sure exactly what you want to know?

[learningtofly]

Depends on the watch. Swapping the mainspring on an ETA 2824 or similar is straightforward, barrel bridge comes off, barrel comes out, train wheels and escapement don't get disturbed. If it's a Valjoux 7750, Omega 1861, Miyota 9015, the barrel is buried in the bowels of the movement so a lot of dismantling is required to get to it and reassembly could potentially affect the lubrication. Likewise a Zenith El Primero. On a vintage Omega 565 or 601 the spring barrel can be removed without fully stripping the movement but a fair degree of skill and care is required.

That's from the horses mouth, there's no simple answer. Not sure exactly what you want to know?

That’s the kind of info I’m after, Paul, hence the question. The watch in question is actually my 5513... the handover didn’t go as smoothly as anticipated and Steve has now confirmed that he needs to install a new mainspring. I guess it’ll need pressure testing again, but I’m also wondering what else might need (re)doing.

[wileeeeeey]

Sorry to hear that Tony. You've been a long time without it, hopefully it can be made right without further delay.

[learningtofly]

Sorry to hear that Tony. You've been a long time without it, hopefully it can be made right without further delay.

Thanks. It was bloody annoying and seemingly a pretty unusual thing to happen. I can’t fault Steve’s response, but I’d just like to speak to him tomorrow from a slightly more informed position.

[walkerwek1958]

I assume the spring has failed shortly after fitting?

Ever heard of the bathtub curve, a plot of reliability vs time? It follows the shape of a bathtub, hence the name. A new component is potentially very unreliable from new because it could have a manufacturing fault that’ll cause it to fail very quickly. If it’s OK it'll be OK for a long time but the potential for failure will gradually increase over time.

If a new mainspring has failed shortly after installation that’s unfortunate and it's probably due to the tiny spot weld holding the bridle to the spring failing, it can happen, if you think it’s annoying as a watch owner believe me it’s worse for a repairer. No money back in the spring, it doesn’t work that way, and he’ll end up spending time re-doing his own work for no reward.

Rest assured, the watch will be fine after having a new spring fitted, don't be too hard on the guy!

[learningtofly]

I assume the spring gas failed shortly after fitting?

Ever heard of the bathtub curve, a plot of reliability vs time? It follows the shape of a bathtub, hence rhe name. A new component is potentially very unreliable from new because it could have a manufacturing fault that’ll cause it to fail very quickly. If it’s OK it'll be OK for a long time but the potential for failure will gradually increase over time.

If a new mainspring has failed shortly after installation that’s unfortunate and it's probably due to the tiny spot weld holding the bridle to the spring failing, it can happen, if you think it’s annoying as a watch owner believe me it’s worse for a repairer. No money back in the spring, it doesn’t work that way, and he’ll end up spending time re-doing his own work for no reward.

Rest assured, the watch will be fine after having a new spring fitted, don't be too hard on the guy!

I understand that, Paul. Can you just advise me what I should expect to be done before the watch is returned to me?

[walkerwek1958]

I understand that, Paul. Can you just advise me what I should expect to be done before the watch is returned to me?

Best advice I can give is to trust Steve to make it right, he’ll be more pissed off than you are. Be careful not to give the impression that you’re undermining his judgement, just let him get on with it. The movement needs partially stripping to get at the spring barrel, very straightforward, but v. frustrating when you’ve just had the thing apart and you’re having to do the work again. It’s embarrassing for a repairer when a new part fails, customers are very fickle and some are reluctant to accept the explanation. It’s a no- win situation, repairer has to suck up the cost of the part and the wasted time, he ends up spending an hour or two working for nothing, and some customers will always gave doubts.

Don’t worry, he’ll sort it, he won't be happy but he’ll sort it for you. New spring gets fitted, watch gets tested and regulated again ( if required), hopefully the new spring will be fine for many years.

I’ve said it many times, I’m glad I don’t do watch work to make a living, it can be bloody frustrating to say the least.

[learningtofly]

Best advice I can give is to trust Steve to make it right, he’ll be more pissed off than you are. Be careful not to give the impression that you’re undermining his judgement, just let him get on with it. The movement needs partially stripping to get at the spring barrel, very straightforward, but v. frustrating when you’ve just had the thing apart and you’re having to do the work again. It’s embarrassing for a repairer when a new part fails, customers are very fickle and some are reluctant to accept the explanation. It’s a no- win situation, repairer has to suck up the cost of the part and the wasted time, he ends up spending an hour or two working for nothing, and some customers will always gave doubts.

Don’t worry, he’ll sort it, he won't be happy but he’ll sort it for you. New spring gets fitted, watch gets tested and regulated again ( if required), hopefully the new spring will be fine for many years.

I’ve said it many times, I’m glad I don’t do watch work to make a living, it can be bloody frustrating to say the least.

Tha is very much. I don’t intend giving anyone a hard time over it, and thanks for confirming what I should expect.

[Hood]

Best advice I can give is to trust Steve to make it right, he’ll be more pissed off than you are. Be careful not to give the impression that you’re undermining his judgement, just let him get on with it. The movement needs partially stripping to get at the spring barrel, very straightforward, but v. frustrating when you’ve just had the thing apart and you’re having to do the work again. It’s embarrassing for a repairer when a new part fails, customers are very fickle and some are reluctant to accept the explanation. It’s a no- win situation, repairer has to suck up the cost of the part and the wasted time, he ends up spending an hour or two working for nothing, and some customers will always gave doubts.

Don’t worry, he’ll sort it, he won't be happy but he’ll sort it for you. New spring gets fitted, watch gets tested and regulated again ( if required), hopefully the new spring will be fine for many years.

I’ve said it many times, I’m glad I don’t do watch work to make a living, it can be bloody frustrating to say the least.

To be fair I think Tony said the service was going to be the best part of a grand so there's probably a bit of scope for remedial work to be done without it going into a loss situation for him.

[classics]

I assume the spring has failed shortly after fitting?

Ever heard of the bathtub curve, a plot of reliability vs time? It follows the shape of a bathtub, hence the name. A new component is potentially very unreliable from new because it could have a manufacturing fault that’ll cause it to fail very quickly. If it’s OK it'll be OK for a long time but the potential for failure will gradually increase over time.

If a new mainspring has failed shortly after installation that’s unfortunate and it's probably due to the tiny spot weld holding the bridle to the spring failing, it can happen, if you think it’s annoying as a watch owner believe me it’s worse for a repairer. No money back in the spring, it doesn’t work that way, and he’ll end up spending time re-doing his own work for no reward.

Rest assured, the watch will be fine after having a new spring fitted, don't be too hard on the guy!

Do you know how long a mainspring should last?
Mentioned in a different thread, my Omega AT cal 2500 was serviced in 2018 and the main spring and barrel broke/failed in 2021, Omega is giving my watch a service FOC.

[learningtofly]

To be fair I think Tony said the service was going to be the best part of a grand so there's probably a bit of scope for remedial work to be done without it going into a loss situation for him.

Yes, I was going to mention that, as it happens. It's hardly the end of the world for Steve, and with a 6 month turnaround time I'm sure an hour here and there won't cause any lost sleep.

[learningtofly]

Quick update in that the mainspring - which had broken along its length, rather than at the weld - was replaced over the weekend. The watch has been tested again (+2spd over 24hrs, which is fine given that it's just for confirmation that all is still okay), and is about to be couriered back to me.

Updated update: Watch on the wrist as of 3.10pm today. I can only say that it was a superb response from Steve, and I literally couldn't have asked for more.

[learningtofly]

Well, I guess I should update this thread again, as I seem to have some further issues that need to be resolved.

When I got the watch back the second time, I checked it over 24 hours and, rather than running at +2spd as advised it was actually -6spd. I then monitored timekeeping over ten days and the results were as follows:

-6
-6
-6
-7
-7
-7
-7
-8
-8
-8

I've spoken to Steve about it, and also about a slight jerkiness that I've noticed as the second hand traverses the dial (and which wasn't there before). He immediately offered to regulate the watch whilst I wait, but I said that I'd want it pressure tested and then monitored for a few days before taking it back again. I would also want the issue with the second hand addressed.

I'm actually trying to arrange for it to be collected at the moment, but my last couple of emails have gone unanswered for some reason. I'm sure all will be fine in the end (and I'll be calling to speak to Steve today if I don't hear back by mid-day), but I'll update this thread with further news as and when.

[Stanford]

Well, I guess I should update this thread again, as I seem to have some further issues that need to be resolved.

When I got the watch back the second time, I checked it over 24 hours and, rather than running at +2spd as advised it was actually -6spd. I then monitored timekeeping over ten days and the results were as follows:

-6
-6
-6
-7
-7
-7
-7
-8
-8
-8

I've spoken to Steve about it, and also about a slight jerkiness that I've noticed as the second hand traverses the dial (and which wasn't there before). He immediately offered to regulate the watch whilst I wait, but I said that I'd want it pressure tested and then monitored for a few days before taking it back again. I would also want the issue with the second hand addressed.

I'm actually trying to arrange for it to be collected at the moment, but my last couple of emails have gone unanswered for some reason. I'm sure all will be fine in the end (and I'll be calling to speak to Steve today if I don't hear back by mid-day), but I'll update this thread with further news as and when.

Who is this Steve you refer to?
There could be any number of reasons why he hasn't replied yet - maybe he's busy looking for fuel.

[learningtofly]

Who is this Steve you refer to?
There could be any number of reasons why he hasn't replied yet - maybe he's busy looking for fuel.

Hah! It's Steve Hale, and we've now spoken (and the watch is being collected today). No complaints regarding Steve, but I'd obviously like the issues sorted now - especially given how long it was away to begin with.

[walkerwek1958]

Surprised at the disparity between Steve’s 2secs/ day claim and the actual performance at -6 to -8. Possibly by returning it quickly he hasn’t given it long enough to settle down. The results are fairly consistent, but as ever I would question the state of wind and wear pattern. Leaving a watch dial-up overnight rather than wearing it to sleep will give more consistent results and that’s what I would do if testing a watch of my own. Also, it pays to get the watch fully wound initially, particularly if you’re not very active.

Having registered the problem with Steve it would make sense to run the watch for 3-4 weeks to ensure it has reached consistency, then have it regulated. A few days should be sufficient but leaving it a little longer would do no harm.

Sometimes a mainspring has to go through a few cycles of being wound and unwound to give consistent performance, this should be evident from the amplitude.

As for insisting on having a watch pressure tested after the back has been removed, it shouldn't be necessary. The caseback seal is relatively thick and it sits in a groove, provided its fitted correctly it’ll be fine after replacing the back.

[learningtofly]

Surprised at the disparity between Steve’s 2secs/ day claim and the actual performance at -6 to -8. Possibly by returning it quickly he hasn’t given it long enough to settle down. The results are fairly consistent, but as ever I would question the state of wind and wear pattern. Leaving a watch dial-up overnight rather than wearing it to sleep will give more consistent results and that’s what I would do if testing a watch of my own. Also, it pays to get the watch fully wound initially, particularly if you’re not very active.

Having registered the problem with Steve it would make sense to run the watch for 3-4 weeks to ensure it has reached consistency, then have it regulated. A few days should be sufficient but leaving it a little longer would do no harm.

Sometimes a mainspring has to go through a few cycles of being wound and unwound to give consistent performance, this should be evident from the amplitude.

As for insisting on having a watch pressure tested after the back has been removed, it shouldn't be necessary. The caseback seal is relatively thick and it sits in a groove, provided its fitted correctly it’ll be fine after replacing the back.

Helpful thanks, Paul. Not sure about the pressure testing issue on a watch of this value, although in reality I wouldn’t take it swimming as there’d be no point risking it.