Interesting case back design - need new gasket?

[coder79]

I'm pretty new and haven't yet serviced an automatic so I picked up a Bulova 23 from eBay. The movement ring + case back is nothing like I've ever seen before and I'm hoping for some advice on the gasket. The watch has a few service marks so I don't know if the existing gasket is original and if I should bother replacing it. It's a milky plastic but seems flexible and not brittle. The inner diameter fitment is a little loose around the movement ring and the outer diameter is larger than the movement ring but matches the case back.

Would you replace it? I haven't found anything similar so I'm not sure if it should be replaced with a flat rubber or red plastic gasket.

[watchweasol]

Hi  If thats how you found it when dismantling ,then return it the same.  They are put there for a purpose,    cheers.

 

[KarlvonKoln]

I'm with Watchweasol, re-assemble it the way it was when you are done.  That seems safest.  Out of curiosity, what make of watch is that on which you are working?  I haven't see that system of case back fitment yet.  Can you share pictures of dial and case?  And of movement?  I confess to being a little curious about it.

[coder79]

Thanks so much for the advice - I'll leave it as it was. I suppose I was comparing the gasket to changing tires or wiper blades on a vintage car.

I was drawn to this Bulova 23 because of the interesting dial and the scalloped bezel. I also found a nice site listing the variants; I think I have the 1955 Variant B.

Full list of Bulova 23: https://mybulova.com/watches/model/bulova-23

1955 "B": https://mybulova.com/watches/1955-bulova-23-b-12459

Sorry about the poor pictures; I only have my phone camera. Also, nothing is cleaned yet.

[coder79]

Less blurry movement picture.

[jdm]

23 minutes ago, coder79 said:

I was drawn to this Bulova 23 because of the interesting dial and the scalloped bezel. 

It's lovely indeed, thank you for sharing. Perhaps the overengineering of the case design didn't help Bulova in surviving what came later? 

[watchweasol]

Its a nice looking and chunky watch. An interesting design but as jdm says overengineered. thanks for the pictures always best to do that along with the questions.      cheers

[KarlvonKoln]

I love how they incorporated their intial "B" into the support structure of the oscillating weight.
And I am glad you were able to date this to 1955.  I have a different make of watch which also has a gold case with a scalloped bezel exactly like that, and the dial is a cream-colored tan with a texture to it also.  Now that I know that was a popular trend at that time, I know my watch was probably made earlier than I originally thought.  I couldn't go by the movement; it was just another HB115, and those were in use for quite a while.  Thank you for sharing that information.

[spectre6000]

Interesting how that scallop in the preload spring(?) is echoed in the bezel. Any idea what the purpose of the preload spring is? Seems like it would help prevent the case back from rattling if it was loose, but if it was loose it wouldn't be sealed at all.

[coder79]

1 hour ago, KarlvonKoln said:

I love how they incorporated their intial "B" into the support structure of the oscillating weight.
And I am glad you were able to date this to 1955.  I have a different make of watch which also has a gold case with a scalloped bezel exactly like that, and the dial is a cream-colored tan with a texture to it also.  Now that I know that was a popular trend at that time, I know my watch was probably made earlier than I originally thought.  I couldn't go by the movement; it was just another HB115, and those were in use for quite a while.  Thank you for sharing that information.

Glad to be of help! It's nice to see what's trending during a time period to better understand what we're looking at. Agreed about the oscillating weight, nice little detail!

 

4 minutes ago, spectre6000 said:

Any idea what the purpose of the preload spring is?

I'm also curious about this. I can feel the spring loading up when I press the case back onto the movement ring but have no idea why. Shock absorber?

[KarlvonKoln]

11 hours ago, coder79 said:

I'm also curious about this. I can feel the spring loading up when I press the case back onto the movement ring but have no idea why. Shock absorber?

I don't know if that was the designed intent but, you know, that's how it could function, now you mention it.  If the movement ring fits close to the movement but is not so tight in the case, then with the spring having a good footing against the case back, it would support the movement at the other end, keeping it snug against the the seat by the crystal.  And yet, this spring would allow for some absorption if the case suffered a hard knock.  Maybe not from all directions, but it would do a little bit.  Interesting...