Waltham 37s 8 day car mounted pocket watch parts

Discussion in 'Watch Repair' started by Icarus723, Oct 20, 2019.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. Icarus723

    Icarus723 Registered User

    Oct 15, 2019
    13
    0
    1
    Male
    Country Flag:
    Hiya.
    I recently acquired a Waltham 8 day 37s car mounted pocket watch. It’s a pretty piece but currently is not functioning.

    It had a broken plate jewel that I was able to repair but it also needs a replacement hairspring. I’m looking for part numbers or model numbers of some kind to get the needed hairspring to get this up and running.

    Any help or direction to any resources would be greatly appreciated. Thanks.

    48D25BA7-C543-4A42-9B8A-BFD446D7A6BC.jpeg
     
  2. richiec

    richiec Registered User
    NAWCC Member

    Feb 24, 2007
    6,715
    536
    113
    Male
    automotive warranty inspector
    Brick, Ocean, NJ
    Country Flag:
    Region Flag:
    28255 I believe is the part number but how many jewels? I can make a difference in the strength of the spring. Any way to straighten out the old one>
     
  3. Icarus723

    Icarus723 Registered User

    Oct 15, 2019
    13
    0
    1
    Male
    Country Flag:
    If there is a way to repair it, it would be beyond my capabilities. Thanks for the info. I will look around for that model number.
     
  4. praezis

    praezis Registered User

    Feb 11, 2008
    461
    26
    28
    Germany
    Country Flag:
    Region Flag:
    Can you post a picture of that hairspring?

    Frank
     
  5. Icarus723

    Icarus723 Registered User

    Oct 15, 2019
    13
    0
    1
    Male
    Country Flag:
    Not any more. It ended up looking like a birds nest so I took it off the balance and scrapped it. It looked like a slinky that’s been through the heavy duty cycle on a dryer.

    I figured even with all the pinching, twisting and crimping I learned on YouTube, it would’ve been more cost/time efficient to just purchase a new one. Little did I know. Lol.
     
  6. Bila

    Bila Registered User
    NAWCC Member

    Jan 22, 2010
    1,082
    278
    83
    Male
    Retired
    Country Flag:

    As Richiec has stated part number #28255 (blue steel) fits these but there are 3 types of strengths, light, medium and heavy, also, they made springs for these in an alloy (Conel) part number #28253. So can you please advise what was on it, blue steel or conel?
     
  7. Icarus723

    Icarus723 Registered User

    Oct 15, 2019
    13
    0
    1
    Male
    Country Flag:
    I’m not familiar with conel, but the original hairspring that was on it had a blue tint to it when the light hit is so I assume it’s the blue steel that was previously mentioned.

    model #28255

    Will that be the factory model number? Or is there a specific universal replacement brand I should be looking for? Was not able to find on eBay.

    Is there any benefit from moving from a light to medium to heavy strengths or is it more like strength specific to the watch and strengths are not interchangeable?
     
  8. Bila

    Bila Registered User
    NAWCC Member

    Jan 22, 2010
    1,082
    278
    83
    Male
    Retired
    Country Flag:
    No universal brand I am afraid to say, that is the Waltham Part number, you will need to work out what strength spring you need otherwise your BPH rate will not be correct, strengths directly correlate to Balance wheel weight:(
     
  9. Icarus723

    Icarus723 Registered User

    Oct 15, 2019
    13
    0
    1
    Male
    Country Flag:
    Is there a way to figure out the strength of a hairspring by looking at it? Length diameter width?

    Thanks for the education fellas.
     
  10. Bila

    Bila Registered User
    NAWCC Member

    Jan 22, 2010
    1,082
    278
    83
    Male
    Retired
    Country Flag:
    No really, you might have to source one of each to try then you still could get a slight variation above or below the rate of 18000BPH, depending on if the balance has had someone fiddle with it:(
     
  11. Icarus723

    Icarus723 Registered User

    Oct 15, 2019
    13
    0
    1
    Male
    Country Flag:
    Thanks again for the education.
     
  12. Whereisitat

    Whereisitat Registered User

    Mar 14, 2017
    84
    9
    8
    Country Flag:
    Yours will be a tad difficult but not impossible.

    You need a donor balance / movement to get a hairspring. That hairspring-if serviceable-will be matched to the balance it is on. Matched by weight that is. So unless you get extra lucky even if you get the right type of hairspring it will need to be tuned to the balance -or more accurately the balance weight adjusted so the rate is proper at the center of the balance cock engravings.

    Swap the hairspring and if the amplitude and everything is running proper the rate will show in seconds a day the variance.

    It may be larger than the machine will rate and you will get ++++ or ------ as a reading. The + means you are faster than 999 seconds a day & another pair of weights is probably where to start. If it is - then removing the smallest pair of balance weights is the next move.

    Once your "on the block" you can make smaller rate adjustments. I prefer to swap the weights instead of modifying them. Or use timing washers just don't file the screws if you can avoid it.

    I always use a simple poise tool-I call them the 'Red Jaws of Justice" to assure the balance has no heavy spots. If the watch is in good order this usually assures close to even rates in position. This is just the start if you want to dial it in-a 15 jewel Waltham 8 day is nearly a chronometer grade unit if running properly. But that is easier said than done.

    Hope you have success with it.
     
  13. pocketsrforwatches

    pocketsrforwatches Registered User
    NAWCC Member

    Feb 13, 2008
    270
    9
    18
    Retired from IBM, now a Watchmaker
    Ticonderoga, NY
    Country Flag:
    Region Flag:

Share This Page