Jump to content

What kind of crystal?


Recommended Posts

I'm hoping to be able to successfully service/repair my first watch, and I'm ordering parts. I thought the crystal would be pretty straightforward, but turns out it's not going to be so easy... To start, it's 0.1mm smaller than the case opening, and there's what looks like a retaining ring that is just loose in the crystal, and the whole thing just slips through the case. Since it's obviously not the correct crystal, I also don't know if it's the correct profile... The watch itself is pretty obscure, and I'm having a hard time finding much anything about it. 

IMG_1810.thumb.JPG.ab2d638e60c3e5c98c43a258091c92f2.JPG

IMG_1808.thumb.JPG.27b45f5e11d07a8d1991c2a2e05104f9.JPG

So, is that a retaining ring, and if so, does that dictate the type of crystal? 

If the crystal is clearly too small for the case, and the retaining ring is too small for the crystal, does that mean I also have the wrong retaining ring, or is it just a very wrong crystal?

IMG_1809.thumb.JPG.65e680602eca387ba456cebb6919cee2.JPG

If the case measures out to 26.1mm, is that the size of crystal to order, or do I go up a size?

Thanks for the help. Looking forward to a big win with this one!

Link to comment
Share on other sites

Well,  first,  what is the name of the watch.    looks like a vitage case.   it might take an aftermarket crystol.  the ring has a couple jobs - like holding the mvt. in the case.   some vintage watches will only acept factory lenses that are hard to find.   a claw tool woud be a good one to buy.    a  watch repair book is good also.  good luck.      vin

Link to comment
Share on other sites

Does the movement have a sweep second hand? if not a low dome glass should do the trick, but you cant fit one with what vinn3 is calling a claw tool. I'm sure he is talking about this type. You will need this type or similar, I picked this one as I had one and I know they are very good. 

HV4266 (2).jpg

robur-watchmakers-vintage-die-press_360_d79b3d4e9117275e50a6ed10ca00f944.jpg

Link to comment
Share on other sites

This is where if you live in the right locations you have a physical material house you can walk into and say crystal and a little while later a crystal will materialize. But local material houses are getting few and far between unfortunately. Except we still have a couple of them in Seattle.

I have some links below as long as that's just a generic tension ring crystal it shouldn't be that bad except you're going to need a press to put it in. First side is a crystal manufacturer download some other catalogs look through him see what you can find. Second link also has what I think are the right crystals. Third link just to show you material house with the same crystals provided I guessed correctly. Then it's also assuming this is just a generic tension ring crystal if it's not you could be screwed which is also why the catalogs are nice because you can if you're lucky maybe find it listed in the catalog somewhere.

 

https://gssupplies.com/plastic/

https://www.cousinsuk.com/document/category/tension-ring-armoured-watch-glasses

https://www.esslinger.com/gs-watch-crystal-et-ever-tite/

Link to comment
Share on other sites

Sorry... It's a Grana from the early-mid 40s (a guess). Certina 304 movement (yes sweep second hand). No idea what the model would be; obscure. I could be wrong about the date... I just read on Ranfft that the Grana name was phased out in 1939, but the Ranfft page for the movement states that it's from a Grana watch from 1945... The 1945 version has 17 jewels, so I'm assuming mine was made prior to that.

Here's are photos of the dial and hands in case anyone has any ideas. Or even if anyone can point me to any other information about the watch. Grana was known to supply watches to the British military during WWII, and the 24 hour markers lead me to think in that direction, but the 16 jewels and sweep seconds hand point me in the opposite direction... Really not sure, and like I said, I can't find a word or image about it anywhere.

IMG_1811.thumb.JPG.c5de43bc9866445ca158d5c8ea201d4d.JPG

IMG_1812.thumb.JPG.bb2b68f12a16dd64ffcf20ec5797b5d3.JPG

I live close to Denver. There's just about nothing here that I'm aware of.

I have a crystal lift and a press.

I'm not sure it is a tension ring, or that it's original to the watch. The crystal it came with is badly cracked, and the ring fits loose in it, but the crystal also fits loose in the case.

 

Edited by spectre6000
Link to comment
Share on other sites

If the case is the type I think it might be (Need to see image of case back.), it will be a bear to find a crystal. It looks like it might be the type of case that Girard Perregaux used in their forties Sea Hawk watches. In those cases the inside diameter of the crystal needs to fit snugly against the outside of the case back. In addition, the bezel must also fit snugly around the outside of the crystal. The metal ring would be a reflection ring that sets down on the dial before the crystal goes on. As was mentioned, it may be the type of case that you'll have to take in/send in to a material house or get very lucky and find one for the brand and size on da Bay.

I have dealt with a few of these. I'll see if my case measurements are the same as yours. If so, I MAY be able to save you a lot of time and hassle. I'll try to look for that info this morning. Good luck. Cheers.

 

Link to comment
Share on other sites

Here's the entire contents of the case tin. It's a two piece case with a split stem.

IMG_1814.thumb.JPG.6b8784f5a0fd5a22ba9bde6746631319.JPGIMG_1813.thumb.JPG.ffdc131238405bc15c6f670d550db420.JPG

The inside of the case back reads:

"Grana Watch Co

Swiss

Brevet

+

Stainless

Steel"

IMG_1816.thumb.JPG.7b8982248b7bca56307f2ad2a33582cf.JPG

The outside of the case back reads:

"Water-Resistant * Shock-resistant * Non-magnetic"

"669

633042"

The numbers are stamped a bit crudely compared to the rest, and I think that might be an ordnance number.

IMG_1815.thumb.JPG.839b88e9dea1e724b9dd2ae18fb947ea.JPG

Link to comment
Share on other sites

It is as I suspected. Those are tough. I suspect that the #669 might be the case design number. Perhaps look for a Grana 669 crystal by GS or other? Even if you find a 669 of another company, and it seems to have same dimensions, it might be worth a shot. Good luck.

BTW, the info I have doesn't seem match your case's spec's. Sorry. If I find something else I'll post.

Link to comment
Share on other sites

Is the ring a "reflector ring"? I see that being a thing in the GS catalog, but photos of such a critter are elusive. Best case scenario, I get a photo of a GS crystal package.

I have measurements of the ID of the case (26.1mm), the OD of the reflector(?) ring (25.1mm), an approximation of the width of the flat area where there could potentially be some overhang (0.5-0.6mm), and the height of the ring (0.87mm), which I just noticed has an unexpected (to me) profile.

There is a flat at the top, then a ~45° bevel, and a thin (just the thickness of the metal) vertical section as seen from the top:

IMG_1818.thumb.JPG.f3e1a2ed97c69cddc821c3f0f3dbef3b.JPG

From the side, the horizontal flat detail is a lip out from the main part of the ring. I expected it to be flush around the perimeter, and thus more substantial if it's performing a structural purpose like locking the ring into the case...

IMG_1817.thumb.JPG.e78847d384f58de54dd773ce3af7c127.JPG

What do those of you more experienced than I make of this in light of the above?

Edited by spectre6000
Link to comment
Share on other sites

The tension ring crystals are normally a decorative ring. Unfortunately some watches like Omega the ring holds the movement in place and it's usually a special shape. you can't just use an ordinary tension ring for Omega. Then you are crystal looks like it's in the same category.

You a try emailing to GS people and see if they have a clue what Crystal you're supposed to use. Depending upon which catalog you have they will list out all the specific shapes and specific watches those specific shapes go in they might even have a section for crystals like this but email and ask that might be easier.

Then the other thing you may have to adapt. Other words you may be elegant a tension ring crystal remove their ring and insert your ring but this may require several crystals to get right crystal it will fit your ring.

Link to comment
Share on other sites

Can someone post photos of a "reflector ring" and a tension ring? The ring here is shiny and reflective, and doesn't seem substantial enough to be a tension ring to my mind, but I've never seen either, and can't find photos of either specifically in isolation. The ring I have fits very nicely into the caseback, and prevents the dial from coming out. Also worthy of note, when all assembled, the top of the ring is approximately flush with the top of the case, and if I had to guess that it was originally part of the case or part of a crystal, I'd guess case.

19 hours ago, MrRoundel said:

Here's a recent discussion that you might find helpful. Getting the right crystal for this type of case on the first attempt might take some luck. Hopefully the right research in finding the mistakes/learning of others will make it easier.

Wyler thread

I've read through this thread several times now, and I'm not completely sure it's the same thing. If I understand, the challenge is that the crystal needs to fit two different dimensions: in ID of the opening in the case AND the ID of the opening in an outer bezel. Is this correct? If so, it appears to be a different animal. If the two dimensions are the ID of the case and the OD of the ring, then we may be on the same page. Based on the dimensions I have, if the crystal is ~0.5mm thick around the perimeter, then I may not need anything all that special... 

Edited by spectre6000
Link to comment
Share on other sites

Are you, spectre6000, referring to the top part as the "case"? I would refer to it as a bezel, with the case-back actually encasing the watch. With the cases that I refer to, the crystal's ID fits over the case-back's OD until it is stopped by a ledge on the case-back. The bezel then goes over that assembly until it fits snugly and at the right depth to look right and hold onto the OD of the crystal. That said, yours may be more about the crystal fitting the case-back well and the bezel being a good friction fit to the larger case-back diameter below the crystal. If that is the situation, then the bezel should fit the case back snugly without a crystal being installed. With my Perregaux model this is not the situation. Cheers.

Edited by MrRoundel
Link to comment
Share on other sites

I'm sure that the ring is a pure reflector, not a tension-ring. If it was a tension ring, and it sat below the rim of the case back, it would have a hard time tensioning anything worthwhile. The movement sits in the case back, the reflector ring goes on top of the dial, the crystal goes on, and the case-back gets pressed through the bezel/case.

Yours is not the first crystal I have seen that is cracked in those places. What it may be is that the crystal was correct but shrunk as plastic crystals tend to do. If the crystal shrinks without somehow convincing the case-back to shrink along with it, something's gonna give. This doesn't make it any easier to choose the right one, does it? If you measure the OD of the existing crystal, you should probably take it up on size due to the shrinkage.

I'm still curious if the case/bezel will fit snugly against the back without the crystal in place. Regardless, this is the type of case that the GP's use. Benrus also used them, as they made a special tool for dealing with these case.

 

DSC06669.JPG

Edited by MrRoundel
Link to comment
Share on other sites

Case/bezel and back only = loose.

Case/bezel, back, and reflector ring = loose.

Case/bezel, back, reflector ring, crystal = tight.

Case/bezel, back, crystal = maybe slightly less tight.

So, we've solved this mystery on its face. I'm with you 100% on the shrinkage. Now I need to find an actual crystal... GS states pretty clearly that hobbyists should contact a watchmaker or jeweler to find replacement crystals. Not helpful. If I'm to call to try to figure out which crystal in their catalog will get me where I need to go lacking published information of the critical dimensions in their catalog, what do I say to sound credible enough for them to talk to me?

Edited by spectre6000
Link to comment
Share on other sites

Yup, it sounds like the bezel/case has to cinch down against the crystal. If I were you, I'd measure the OD of the existing crystal and go one size  up, if you can find it. But even if you get that right, who can say what the brand and thickness of the crystal might be? Warning: Even doing this is not guarantee that it will work. This is probably why the watch still had the cracked crystal installed. These are a royal PITA. If everything is held together fairly well with the old crystal, you might consider getting a watchmaker to buff out the crystal. Or if you have the tools, do it yourself. With the crystal polished, you might learn to live with the cracks. They don't seem to be in areas that they'd inhibit reading the time. Best of luck.

Edited by MrRoundel
Link to comment
Share on other sites

  • 2 weeks later...

Crystal finally arrived yesterday. Looked the part save maybe a touch taller. Installed, and it's ever so slightly loose in both critical dimensions! Unfortunately, it can't be glued in or anything because it holds the bezel to the case back! It's more loose on the case back than the bezel, and it'll barely hold onto the bezel. The net effect is that when it's installed, the case back spins freely or just falls out. If I glued it to the case back, the friction fit to the bezel is so light that it would fall out that way... Mega bummer. Back to the drawing board.

Any other crystal manufacturers that seem likely to have a match?

Link to comment
Share on other sites



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • I voted leave too, my reasoning was the the EU is undemocratic, no elected officials. I don't regret it but I  am sad that both sides acted like petulant toddlers.  Shameful.  I'm not on other forums but if I was and left this site, would you shun me? Of course not, we aren't petulant toddlers.  
    • This is a type of tool that may be suitable to remove the bezel - though note that I'm pretty sure the watch should be face down - not face up, as in some of the photos of these tools on amazon & ebay! If you try one one of those, put the movement screws back in first to avoid accidents. https://www.amazon.co.uk/Removal-Professional-Remover-Watchmaker-Diameter/dp/B09XCH4QVN?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&smid=A296NCMMFVXSDN&th=1  
    • Hi, I’m constantly asking my wife to help me with removing the stem in order to complete casing. To expand, this is not a challenge for me when the setting lever is secured by a screw (older calibers). However when the setting lever is attached to a spring loaded setting lever axel, like on more modern calibers, I simply don’t see how to apply enough pressure on the button to get the stem out short of putting the movement face down with the dial and hands attached, which I’m loath to do in order to avoid damaging the dial/hands? what technique should I be using? thanks  
    • Many thanks for your advice (being borne in mind at present) & offer Dell. When I was given the clock the plastic anchor was loose on the arbour (it had split at the 'hole') &, after repairing this, I have been trying to determine whether the spindle (pin) should be perpendicular when the pallet is sitting on a flat surface; or whether, when installed, its L-R extremes (or alternatively its tick & tock points) should lie at equal angles from the vertical when moved with spring absent. I can get the clock to run but in every such configuration the top block has to be turned anti-clockwise (from above) by quite a bit in order to be 'in beat' & it always runs fast (despite the pendulum being set to as slow as possible). This makes me wonder if there is any particular feature of/fault in a torsion spring clock which determines which turn direction (if any) is necessary to get it 'in beat'; & whether there would be a different set of settings that would get it running nearer to time at somewhere around the mid timing/inertia position which would then allow tweaking of the fast/slow setting.
    • Now this has happened I bet China or India just to name two will start to produce none genuine parts.  I did. But idiot Boris Johnson failed miserably in his negotiations. The E U stitched up the UK like a kipper. Nigel Farage  offered his help but big head Boris declined. So this is why we are in this mess all because Johnson wasn't clever enough.  
×
×
  • Create New...