1925 Waltham is trying to win a marathon:

[KarlvonKoln]

I have a GORGEOUS 1925 Waltham grade #210, and I think it's high on speed.  It's running way too fast and I've been trying various ways of reigning it in.  When I searched the forum, and queried within the post titled "Meantime Screws", @JohnR725 suggested my best bet was to start a new post about its particular problem and traits.
History: the watch is a flea market find (only $20! I had to) and I knew it did not run.  It is my intent to sell it later - so there is no hurry on the repair, and it is also for practice and experience.  Inspection revealed that it had a broken balance staff and a cracked upper cap jewel, as well as needing much careful cleaning.  I also installed a much prettier dial from one of my parts movements.
First I stripped and cleaned.  Then I replaced the cap jewel with an identical cap jewel from a donor.  I measured it out and as near as my measurements show, it had the right depth, in addition to being the correct diameter.  Then I obtained a replacement balance complete for this grade.  I examined the pivots and they were good. I checked that it was true, and poised it.
(It is here that I interject that JohnR725 made a good point, in that I do not know the history of this balance, nor how it behaved in its former movement.  It could have difficulties inherent in it, which I am only now discovering.)
When the replacement balance was being fitted and beat adjusted, I noticed it was seemingly unavoidable that the watch would run excessively fast.  At first, more than an hour and ten minutes fast per 24 hours.  So here is what I tried.  I checked end shake and side shake, and it seemed pretty good, very slight on both counts. At first I set the regulator all the way to the slow end (with little improvement, but I kind of saw that coming).  Then I demagnetized.  Checked with compass.  Cleaned the hairspring carefully with a very soft artist brush in naphtha.  Under magnification it was then spotless.  Reinstalled hairspring and checked its shape and the shape of the overcoil.  It looked so good that I knew I couldn't make it any better.  Reinstalled balance and checked for clearance on every little blessed thing - the screws, the coil, the nearby wheel, the horns, the guard pin, any thing I could think of.  I checked the jewels to make sure I didn't over-oil or under oil.  At the end of everything, this watch still runs 48 minutes fast with the regulator set all the way to the slow end.  
Before I even try timing washers, or to play with the meantime screws, I thought I would post here and (at the risk of being told I missed something obvious and feeling silly) I would ask you wonderful people what you might come up with, if you were in my shoes.  All ideas welcome (short of dynamite).  

Re photos - once she runs down, I plan to get the best close-ups I can of the balance, and whatever pics someone wants to see better.  

Edited September 11, 2021 by KarlvonKoln

[JohnR725]

it would be nice to have a picture of the original balance wheel next to the replacement balance wheel. You don't have to take the replacement off the balance bridge  could just taken out of the watch so we could see the entire balance wheel next to the original.

then my suspicion is you going to have to steal some screws off the original balance wheel a pair of them and see what that does for slowing you down.

 

[KarlvonKoln]

9 hours ago, JohnR725 said:

it would be nice to have a picture of the original balance wheel next to the replacement balance wheel. You don't have to take the replacement off the balance bridge  could just taken out of the watch so we could see the entire balance wheel next to the original.

then my suspicion is you going to have to steal some screws off the original balance wheel a pair of them and see what that does for slowing you down.

 

I will do that later then (busy day ahead of me).  And it reminds me: the hairsprings of each looked the same...but...I think I should measure and count coils.  I have kept it in the back of my mind that I could try the old hairspring on the replacement balance and see what kind of results that produces.  
You will all notice when I post the pictures of the former, and replacement, balance side-by-side  - that last night I scavenged a couple screws from the old one.  These helped to reign it in somewhat but, alas, not enough. I was careful to place them in the area midway between the middle of the rim and the arm; I figured if I placed them any further out on the rim I would then need to worry about my temperature adjustment, and I wasn't ready to go down that path. Thus my writing to you all.  More pics to come by end of day.
I also have one other question: the plates need a bit of polish.  I haven't owned a scratch brush yet (still building my tool collection) and therefore have not used one on nickel plated brass.  This watch's plates are nicely decorated but have numerous very fine scratches and tool marks. Some appear on the case also.  Is there a reliable method for safely reducing some of the less-aesthetic marks, outside of the thorough cleaning I usually do, without marring the damaskeening?

Edited September 11, 2021 by KarlvonKoln

[Nucejoe]

17 hours ago, KarlvonKoln said:

Cleaned the hairspring carefully with a very soft artist brush in naphtha. 

Goodness.     How do you brush a hairspring? 

Did you give it a final rinse in IPA or ligther fluid or one dip?  and  blow dry with hairdrier on hot air? 

 

[oldhippy]

If all is well with the hairspring and the regulator is over to slow and it is still gaining, if you can  you let the hairspring  out making it longer than you re-pin it, you will then need to adjust so the balance is in beat. 

[HectorLooi]

What rate and amplitude are you getting with the new balance?

[KarlvonKoln]

21 hours ago, Nucejoe said:

Goodness.     How do you brush a hairspring? 

Did you give it a final rinse in IPA or ligther fluid or one dip?  and  blow dry with hairdrier on hot air? 

 

Re brushing a hairspring: it is a technique that I read about in the *DeCarle book. For somewhat stubborn grime, I use a Windsor-Newton size 00, because W-N artist brushes are very soft and do not shed.  I then rinse with naphtha and let dry on watch paper under a clear plastic dome.

Edit: *Practical Watch Repairing, page 97.

Edited September 12, 2021 by KarlvonKoln
Additional information

[KarlvonKoln]

19 hours ago, oldhippy said:

If all is well with the hairspring and the regulator is over to slow and it is still gaining, if you can  you let the hairspring  out making it longer than you re-pin it, you will then need to adjust so the balance is in beat. 

Thank you, O.H.  I may need to try this.  I think, first I will swap the old hairsping back on, and see what results I get with it.  But if that makes things worse, or about the same,  I will try expanding the hairspring circumference.  But I will keep my timing washers close at hand.

[KarlvonKoln]

On 9/10/2021 at 11:49 PM, JohnR725 said:

it would be nice to have a picture of the original balance wheel next to the replacement balance wheel. You don't have to take the replacement off the balance bridge...

 

First couple photos are of the replacement balance as installed.  Next three are of the original balance with the broken pivot (which I have already scavenged for screws).  They are the best pics I am able to take, so I hope they will help.  Note also, the upper cap jewel has been replaced with one whose measurements seemed to match perfectly at the time, but I am inclined to re-examine it.  I am also thinking that, when the original balance still functioned, an earlier technician may have adjusted it all to run with the cracked stone and, now that I have replaced it, I possibly am finding myself learning to undo all prior "adjustments"?  Either way, please see pics below.  I eagerly await all your suggestions. 

[KarlvonKoln]

Addendum: I did notice that some of the replacement balance's timing screws had been undercut.  I have replaced them with solid ones from the old balance.  That is one of the ways I got her down to 48 minutes fast per 24 hours.  Still a long way to go though.  Some of these difficult watches - they are my best teachers.

Edited September 12, 2021 by KarlvonKoln

[JohnR725]

19 minutes ago, KarlvonKoln said:

I may need to try this.  I think, first I will swap the old hairsping back on, and see what results I get with it.  But if that makes things worse, or about the same,  I will try expanding the hairspring circumference. 

always get this weird feeling of déjà vu like I've done this before oh wait I have? Just to remind everybody hairsprings are vibrated for each balance wheel for the most part. This is why typically on a wristwatch you can't just swap hairspring and have everything work visually they may look perfect but it's not just the visual there is little tiny differences that can have a dramatic effect on timekeeping.

American pocket watches especially with the over coil to get that shape perfectly right they premade the hairsprings. Typically they used to come in three strengths week medium and strong the hairsprings would all look identical because they have to physically fit in the exact location.

20 hours ago, oldhippy said:

if you can  you let the hairspring  out making it longer than you re-pin it,

typically on old American pocket watches and a lot of European watchesthey hairspring is extended beyond the stud and the procedure described above works perfectly. But look carefully at your picture you see any extended hairspring sticking out I don't. This means that this will not work you cannot change that hairspring.

27 minutes ago, KarlvonKoln said:

I will try expanding the hairspring circumference. 

I'm really confused by of this? Changing the circumference will just mutilate your hairspring and will not affect timekeeping at all so I'm confused with you thinking here?

6 minutes ago, KarlvonKoln said:

I did notice that some of the replacement balance's timing screws had been undercut.  I have replaced them with solid ones from the old balance.

this is why when removing screws from an existing balance wheel verse is brand-new screws must keep them as a matched pair otherwise you going to have to re-poise your balance wheel.

The only way you're going to get this to work is to add enough weight to get reasonably close. Then you can use the timing washers and finally the mean time screws but do remember to put the regulator back in the center position when you're doing all of this rather than  later on because then it's a lot easier if you're working with the regulator and the center position in the first place. That way you can do the minor little bit a regulation with that at the very end.

 

[oldhippy]

Swapping things around when it comes to the balance is not recommended. The timing screws and how they are set are for that particular balance only. No wonder you are having trouble with the timing.   

[KarlvonKoln]

Thank John and OH.  You gave the answers I thought I might hear.  No easy fix here, which is as expected.  I see the way the stud is set, so I won't get anything extra from there.  And if trying to stretch the hairspring outward is a dumb idea then I will skip that.  I have been keeping the screws matched, and poising now and then.  I will leave the hairspring with the balance it came with (unless all else fails) and just keep brainstorming and troubleshooting.  I will check for magnetism again too.  Who knows.

[Nucejoe]

  Thanks for your response Karl, I probably ruin the hairspring trying to brush it, just didn't know it can be done.

As mention expanding circumference will not affect timing, as timing is a direct function of length in both coils and pendulium watches.

Regs 

 

[JohnR725]

if you look at the bottom of the original balance wheel is there a number scratched on the arm? It should be the complete serial number for the movement. If it is then look up the replacement balance wheel and give me the serial number I will look up and see whether it actually goes to watch like yours or not.

 

[KarlvonKoln]

21 minutes ago, JohnR725 said:

if you look at the bottom of the original balance wheel is there a number scratched on the arm? It should be the complete serial number for the movement. If it is then look up the replacement balance wheel and give me the serial number I will look up and see whether it actually goes to watch like yours or not.

 

Well, I can tell you all I know about it: the balance arms are marked with 2511 on one arm and 6658 on the other. And I checked Pocket Watch Database to be sure that 25116658 pulls up a grade 210.  At a glance the balances looked identical.  The hairsprings have the same count to the coils (counted from the bend at the overcoil).  The rim is the same height/thickness. End shake and side shake are fairly slight; better than I'd hoped for.  In all, it's pretty much a perfect fit.  I'm wondering if there is something weird with the hairspring. 

Should I maybe learn how to vibrate a hairspring?  

[JohnR725]

1 hour ago, KarlvonKoln said:

I'm wondering if there is something weird with the hairspring. 

that's why had you check the serial number of the balance wheel. So we know both balance wheels are identical at least as far as the watch they go in. Will assume the original hairspring that came in the watch is correct so take that hairspring and put it on your replacement balance wheel. Because as I said before the hairsprings typically came in three strengths somebody might a swapped another hairspring and visually you cannot tell.

then he'll have your replacement balance wheel with the old hairspring you can see what the timekeeping errors. Make sure you put the regulator back in the center position. Also make sure the mean time screws are not all the way in or out they should be in a neutral position. Plus remember what those if you screw around with them too much they lose their ability to stay in one place though actually become loose switches are not supposed to be.

Then we can see how far off your off for timekeeping in and start playing with the screws. It would be nice to have a factory screw assortment then you know exactly what you're doing but it's hard to find things like that.

 

[oldhippy]

As it's a bimetallic balance wheel it should keep very good time. But the alterations you have done will not help as it is proving to be. 

[KarlvonKoln]

Well, I have photos of how it was before, so I know which screws I added.  I can put it back the way it was.  And John, I'm beginning to think you may be onto something here: someone could have swapped the hairspring on this replacement balance long before I got it.  No way of knowing; they don't bother marking the serial number on a hairspring.  But something tells me somebody before me has tinkered with it.
Next step may be to put it back as it was, and see what the original hairspring would do on this balance.  At least I'm getting good at truing and poising.  But, this watch being a personal project, I may need to set it aside for a time.  I have several others on my bench that I am being paid to service, one of which is a Seiko automatic - and it will get a bit involved.  But I will post again soon enough when I have more time to brainstorm on it.

[KarlvonKoln]

UPDATE: having put the replacement balance back to where it started, with just the screws it came with, I decided to go ahead and try the original hairspring on it.  And, Glory be!, it's slowed down enough that I should be able to regulate it properly!  I wore the watch yesterday to work, and at the end of the day (eleven hours total, by the time I got home and changed) it was only behind by about 48 seconds.  I can deal with that.
So, here is what I suspect is going on.  As JohnR725 pointed out to me - " the hairsprings typically came in three strengths somebody might a swapped another hairspring and visually you cannot tell."  That's very true; I cannot tell.  The old hairspring, and the hairspring that came with the replacement balance are visually identical, down to size, thickness, coil count, everything.  But clearly they are tempered to different strengths.  And as Old Hippy pointed out, that's enough of a difference that all the horsing around I was doing with it would not have accomplished anything but more hardship.  I have to agree at this point: I think that replacement hairspring was originally made and vibrated for a MUCH heavier balance.  How it got stuck on this replacement balance is a story I may never know, but it certainly was a bad fit.  My original hairspring was in excellent shape, and seems to accommodate this replacement balance very well.  And once in beat, it falls into a range I can much more easily regulate. Thank heaven for that.  But I know full well that I got lucky.  O.H. isn't kidding.  Swapping balance parts around is kind of like playing "watchmaker's roulette" - you'd be gambling, and your chance of success is worse than you think.

Dang - I wonder if I should even hang onto that other hairspring.  If I ever encounter a balance wheel made out of lead, I guess I'll know what to reach for.  But this was another small adventure.  Live and learn.