Incabloc-ish, can a balance jewel be reset?

[NigelTufnel]

Hi all,

This may be a silly question but I haven't seen it addressed before.  I have an old Vostok 2809 which could use a new balance jewel,  not the capstone.  I'm really terrible at finding parts, but someone from Ebay suggested I could just remove the hole jewel from the setting and replace it easily.  Is that possible, or am I better off finding better places to shop?

I'm not even sure if this is a real Incabloc setting or a Russian "homage."  If so, I'd also love to buy a dozen replacements for the springs, for um, reasons.

The jewel the brass ring is 1.4mm wide and pivot diameter 0.3mm.

Thanks!

 

Edited September 16, 2024 by NigelTufnel

[NigelTufnel]

I can't measure a thing.... sigh.  1.4 overall diameter, 0.9mm jewel diameter and hole of 0.15mm is probably closer.

[mikepilk]

Changing the chaton jewel?  I've never tried it, not sure how you would get the jewel out without damage.  Might be easier to try to find if the parts on common on cheaper movements, then look for one of those for parts.

[nickelsilver]

Imagining they use a jewel size that corresponds to standard replacement sizes (on diameter and hole), there's still the issue of the jewel height. In a shock setting that would be strictly controlled, to provide the proper gap with the cap jewel. Jewels aren't made to a fixed standard, and a few hundredths difference of height could be make-or-break. That's aside from the issue of of pressing out the old one and in the new one without damaging the setting.

[VWatchie]

I would suggest that you try to find some donor movements on eBay. Often these Vostok movements can be had for very little money and in the process you get spare parts for future use.

Before the war in Ukraine, there were many Russian sellers of these movements, but as of the war, they have disappeared. I guess Russian watch collectors are evil people. Anyway, still a lot of Ukrainians selling these movements, but they are in my experience a lot more deceitful than the Russians used to be so be observant!

Edited September 17, 2024 by VWatchie

[nickelsilver]

On some old pieces that use an uncommon shock setting, I have converted them to Incabloc. I know it's best not to alter things, but I always managed to get one in without having to ream the plate or something (sometimes requires turning up a thin bushing though). So if down the road it's discovered that it's some sort of museum piece, it could be brought back to originality .

[mbwatch]

14 minutes ago, nickelsilver said:

I have converted them to Incabloc. I know it's best not to alter things, but I always managed to get one in without having to ream the plate or something

You find the pivot sizes are usually compatible too, or do those ever need modification?

[nickelsilver]

3 minutes ago, mbwatch said:

You find the pivot sizes are usually compatible too, or do those ever need modification?

For a given Inca reference, there are several hole jewel sizes available. So supposing you find in your stock of parts a "bloc" that would be a good fit, but the hole jewel is over/undersize, you can get or find another that would be correct.

 

Inca's website has lots of useful into. "Sus" means upper, "sous" is lower; if you look at the different models on their site the refs end in /0. In practice you add -10 for example for a hole size of 0.10mm. I have some here straight from the factory, "sous", 100.935.20.000/0-10. That's a lower bloc, with 0.10mm hole. The odd thing is on their site, this ref is listed as 935.20/0. My guess is the first 100 is the hole size in microns... the rest?

 

I have some older (like 50 years old) factory packaging where they simply write the hole size before the ref, like 9.104.12.262, where the first number is the hole size. If you know the ref you want, a good supply house will figure it out. All the current models are on the link above.

[VWatchie]

I'm not sure but the following lot could possibly be worth making a offer if you're looking for spare parts.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2332490.m570.l1313&_nkw=315358235604&_sacat=0

[nevenbekriev]

1 hour ago, VWatchie said:

I'm not sure but the following lot could possibly be worth making a offer if you're looking for spare parts.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2332490.m570.l1313&_nkw=315358235604&_sacat=0

I guess that You have never seen 2809. None of watches in the lot has this movement. Actually, there is not plenty of them.

@NigelTufnel, how did You decide that the hole jewel of the setting is for replacement? Is it broken?

[NigelTufnel]

2 hours ago, nevenbekriev said:

I guess that You have never seen 2809. None of watches in the lot has this movement. Actually, there is not plenty of them.

@NigelTufnel, how did You decide that the hole jewel of the setting is for replacement? Is it broken?

Hey @nevenbekriev - Under a microscope there appears to be a hairline fracture that doesn't quite touch the pivot hole yet.  I have a replacement from a donor, but it's suffering from very odd pitting on the inside face, and salt-like debris which Naptha and IPA have failed to completely remove.  It's much better though.

[nevenbekriev]

In the oldest USSR jewels You may see things that look like debris or pitting, but they may be actually in the structure of the stone. What the results from free oscillations test are? Is there noise from the balance pivots rotating in the jewels?

[NigelTufnel]

1 hour ago, nevenbekriev said:

In the oldest USSR jewels You may see things that look like debris or pitting, but they may be actually in the structure of the stone. What the results from free oscillations test are? Is there noise from the balance pivots rotating in the jewels?

No noise, and the 'cracked' jewel passes the free oscillation test just fine.  I think I'll leave it alone for now and save the donor jewel (pitted) as a spare for now.  Next is the new mainspring which should arrive tomorrow.  I'm super excited.