Cracked crystal repair?

[rjenkinsgb]

Hi all,

I recently got a watch from ebay that looked interesting, with the day & date at the 6 o'clock position. In the photos the crystal appeared to have some deep scratches, but not so bad they couldn't be removed.

However, when I got it - they are cracks. Has anyone had any success repairing such damage?

I'm going to try some dichloromethane acrylic solvent, if there are no better ideas? I know it will mark the surfaces - but if it can penetrate and allow the cracks to seal, re-finishing the surfaces is not too bad. Or does anyone know a supplier of these shaped crystals??

 

It looks pretty good other than the crystal; though the back was incredibly tight and somewhat scratched from a previous owners attempts to remove it, once that was removed it's got a nice clean, running FHF908 25 jewel movement with three service marks inside the back. The case is solid stainless steel so no plating to worry about, it should clean up well.

The service marks appear to be: 68128, H/R 12/75, 7106 - are those 1968, 1975 & 06 or 71?? - or possibly the 78128 was the sellers marking? I've no idea what they really mean?

I am going to have to drill out the end of one of the strap pins - both pins were bent & mangled, one broke trying to remove it.

 

 

[AndyGSi]

What size is the crystal and do you know it it's an underlay?

[rjenkinsgb]

That looks good, though a bit too small unfortunately.

The part I can measure above the case front is 26.85 wide x 28.81 high.

Underlay? - do you mean an inner lip? I'll have to take the movement out to find out.

[AndyGSi]

It's an outer lip that 'underlays' the bezel to hold it in place.

[rjenkinsgb]

So, a new and interesting problem - the movement ring is corroded in place.

It looks like it has a lip that forms half of the groove for the (missing) back seal ring, and that area it tarnished or has some form of sediment all the way around. The movement will loosen from the ring easily enough, but can't go any where due to the dial, as long as the ring is in place.

There is nothing I can see to grip or pry the ring out without touching the movement?

It does look to run pretty well though!

[AndyGSi]

Are you sure it's a ring that's corroded in place and not just part of the case.

[rjenkinsgb]

There is a definite line and slightly uneven step in the middle of the seal groove, with the ring almost perfectly flush at one side and slightly raised at the other - I can't see it being part of the case?

The movement is small enough that is could be a front loader, though I don't know about the dial - but I can't imagine how the crystal could be fitted and sealed from the front? A lip and seal seem more likely?

[mikepilk]

17 minutes ago, rjenkinsgb said:

So, a new and interesting problem - the movement ring is corroded in place.

I can't see a bezel at the front, so the dial must come out the back, so the movement ring must come out. It's odd that there are no cut-outs in it to allow you to pry/lift it out. 

I would put some WD40 along the joint and leave it overnight. 

[RichardHarris123]

The type of case screw suggests it comes out of the front. 

[Neverenoughwatches]

It make no sense for it to have such a large diameter screw-on back and have the movement come out front ways. I'm of the opinion that this ring sits to a lip on the case inner and the clamps pull the movement back to its position. The clamps are holding the ring, pulling the ring.....you are trying to take the ring, the movement and the dial all together....it's probably jamming .

[mikepilk]

44 minutes ago, RichardHarris123 said:

The type of case screw suggests it comes out of the front. 

Normally it does, but it doesn't look like the movement would fit through the front. 

Had a quick Google and found a few Sandoz with that movement and similar screws, but the movement rings had cut-outs so they could be grabbed.  I wonder if that movement ring has been fitted inverted?

Edited April 12 by mikepilk

[AndyGSi]

Confirming if the bezel is removable or not would show if it's a front loader.

Edit

I presume you've removed the clamps screws as highlighted by @RichardHarris123

Edited April 12 by AndyGSi

[rjenkinsgb]

Got it!

I put a tiny amount of evaporust around the seal ring using a thin wire and left it ten minutes or so. I could see it wicking in to the gap in places, so went around it with micro swabs - and it pulled a load of crud out.

The ring then moved quite easily and could lift it out by prying alternate sides.

The crystal is weirder than I thought - round inside, with a pressure ring as well!

[AndyGSi]

Now you've got access what's the diameter of the crystal.

Edit

Looks now like the bezel has to come off unless you can somehow remove it from the back.

Edited April 12 by AndyGSi

[rjenkinsgb]

It's a solid case, with the crystal a press fit from the back. It pushed out quite easily; there is a groove in the case outside the round part of the crystal that has a seal in it. The crystal o/d at that point is 31.0mm

[oldhippy]

It was so easy in my time I would send the case away to one of my suppliers and get it back in a few days with a new glass. These days this country is bloody useless. 

Edited April 12 by oldhippy

[JohnR725]

1 hour ago, oldhippy said:

It was so easy in my time I would send the case away to one of my suppliers and get it back in a few days with a new glass. These days this country is bloody useless.

Yes the old days before things went online and you could physically find things. Like material houses or watch repair shops in the case of Seattle there were all located near fourth and Pike street in downtown Seattle. So if you are working downtown and you needed a crystal sometimes the material houses would actually pick up and deliver other times you could just run downstairs that was my favorite when I worked in one of the buildings were the material house was located. Take a walk usually had run down the stairs as the elevators were a bit unreliable and sometimes had have orders stopping in between places felt much safer coming down the stairs. But still run down the stairs leave your watch cases with them come back later on and all the crystals would be fitted or whatever else he needed fitted or found.

Then the same material houses used to do a lot of business by mail-order people farther away we just send their stuff in and get their crystals whatever fit. Or the days of fax machines various watch shops used to fax in their orders and they would be mailed out.

But nowadays everything is online if it's not online it is? Some of the physical material houses online if you read the fine print indicate that they will still provide the same services they always have and that you can send them stuff that crystals etc. ESF to read the fine print to see if they offer the service. Then there are probably still physical material houses out there I know Seattle still has two of them but they're not online. There must be other material houses across the planet still left finding them can be a bit of a challenge though. But well worth it if still do business with you as they have access to stuff that you don't and it's not all online

the other thing would be go to the crystal manufacturer. Maybe I already have a crystal but if they don't don't make you one.

https://www.gssupplies.com/custom-manufacturing-services

 

 

[mbwatch]

On 4/12/2025 at 2:31 PM, JohnR725 said:

Some of the physical material houses online if you read the fine print indicate that they will still provide the same services they always have and that you can send them stuff that crystals etc

I have noticed a few will offer the service with a phone call, but possibly only to you pros and not to us the mere hobbyists. Which I get it - they can't be running around the warehouse to fit crystals on everybody's Seiko mods or digging out parts to fit a damaged Chinese ST36 movement.