# Sticky  Crystal Fitting....(Challenge accepted)



## lysanderxiii

> Due to the lack of documentation it may be an appropriate time to consider the establishment a thread of threads for crystal fitting. Thoughts, watchmakers?


These days there are basically three types of ways to fit a crystal. Each will require its own specialized techniques to properly install. (Removing can usually be accomplished by pressing with the thumbs on the inside&#8230

*1) Friction fitting
*









This is the method almost all quality sapphire and mineral glasses are installed. The gasket (11) is normally a hard nylon or similar material, and can be either "L" shaped as shown or "I" shaped. The case has a slight undercut or angle cut in the vertical wall so the gasket will flow into it and lock itself in place. Simple friction between the glass and the gasket holds the glass in place. The size of the gasket is critical in the fitting of this type, it has to be the right thickness and the right diameter. To install you need a press that pushes on the outer edge of the glass or uniformly over the entire surface, and the press face and the case need to be parallel, otherwise the glass will become cocked.

*2) Tension ring fitting (r - external, l - internal)**
*









These two are the more common type of crystal fittings for the average diver's, or highly water tight watch, with a plastic crystal. Although, both use a "tension ring" (shown in pink) the installation methods are quite different.

The external tension ring (most commonly seen on Rolexes with plastic crystals) is easily installed by placing the skirt of the crystal on the case so it goes around the raised wall and the tension ring is pressed on. The tension ring compresses the plastic into a good seal, and friction holds the entire assembly together. The press should only contact the metal ring.

The internal tension ring (most common on the rest of the world's plastic crystalled diver's and diver style watches, as well as anything with over 3 ATM water resistance), works by having the plastic skirt squeezed between the case wall and the internal ring (under compression, so 'tension ring' is a misnomer). To install these you should use a press with cone shaped dies. The die wall should come in contact with the crystal at an angle so the force applied by the press both pushes the crystal down as well as tries to reduce the diameter, or roll the skirt under. This helps get the crystal skirt started in the opening in the case.

*3) Mechanical locking (r - clamped, l - wedge)
*









This method is interesting as this method has the highest pressure resistance and the lowest.

The clamped method is the most complicated method to manufacture as the clamp is a separate part and there has to be threads, or a bayonet fitting in the case. But it is the easiest to install, drop in the gasket, the crystal and clamp them together. This method along with the "L" gasket friction fitting offer the best water resistance.

The wedge is the weakest, as far as water resistance goes, and is the only one that uses the "claw"-type crystal tool. To install the skirt must be mechanically compressed to reduce the diameter by approximately .20 to .30 mm then inserted. When the mechanical compression is relaxed the skirt's upper coned shape will force the bottom down into contact with the top surface of the case creating a seal. This is also the most commonly messed up crystal installation. Most people pick the wrong size crystal (one or two sizes too small) and the crystal does not wedge downward with much, if any force. If the crystal can be spun in the case, the crystal is too small. (Some glass in pocket watches are installed in a similar manner, although the ring is usually warmed instead of trying to compress the glass.)

Both of these methods were/are popular with front loaders.

*4) Other less common methods (these days at any rate)
*
Glue. Older square or non-round crystals are usually glued in place.

Seiko. In keeping with doing things different, many older Seikos use mineral glass, a soft gasket and a external, snap on clamp to secure the crystal. The external clamp presses down on the glass pushing it into a soft "L" shaped gasket crerating the seal. The clamp snaps on to the case.


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## Buzz224

This should be a "sticky".

Sent from my SM-N900V using Tapatalk


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## pithy

Buzz224 said:


> This should be a "sticky". Sent from my SM-N900V using Tapatalk


Agreed but the ribs need a little more flesh on them.

http://www.sternkreuz.de/accordion/assets/Sternkreuz_Gesamtkatalog G22.pdf


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## pithy

Almost every day someone makes reference to pressing a plastic crystal into place and there are indeed some thick plastic crystals that are pressed into place but many round crystals are inserted. The delineation as well as the methodology for these seemed to have escaped many. The G & S drawing below illustrates the method quite eloquently. Even though previously referenced it appears to require substantial reinforcement to try to attempt eradication of another horological myth.


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## pithy

The international aspect of the in tension method of round plastic crystal insertion is evidenced in the Sternkreuz tool offerings - specifically the convex rubber plugs and the concave plastic dies.


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## Archer

pithy said:


> Almost every day someone makes reference to pressing a plastic crystal into place and there are indeed some thick plastic crystals that are pressed into place but many round crystals are inserted. The delineation as well as the methodology for these seemed to have escaped many. The G & S drawing below illustrates the method quite eloquently. Even though previously referenced it appears to require substantial reinforcement to try to attempt eradication of another horological myth.


I agree, the G-S press is one I use often - the cabinet was worth the price just for this press IMO (didn't cost much also so that helps):





Easy to install the PA/PHD or similar style crystals using this press, provided the case is not a front loading design. In that instance, the crystal lift or brand specific tool can be used for installation as well as removal.

Cheers, Al


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## pithy

Archer said:


> I agree, the G-S press is one I use often - the cabinet was worth the price just for this press IMO (didn't cost much also so that helps): Easy to install the PA/PHD or similar style crystals using this press, provided the case is not a front loading design. In that instance, the crystal lift or brand specific tool can be used for installation as well as removal. Cheers, Al


Quality hand pliers or a good bench mounted press - fitted with the right accessories - perform very well in this role. The cabinet has a huge advantage over both these types of tools in that it allows the use of both hands to position the crystal and bezel while simultaneously tensioning the crystal and allowing for subtle adjustment of that pressure. If you use one every day you tend to forget about the pleasure of this feature.

The crystal lift - particularly in the hands of one inexperienced in its use or more properly experienced in its disuse - is generally a tool to be avoided. This is a poor tool indeed compared too the factory insertion tools. Start with a set of Mido compression wrenches as they have been frequently available and add to that collection with other brands. You can always sell the overlapping ones or have backups in place. - - - Perhaps someone will post some factory literature outling their use. ----- Use of a quality claw type tool is sometimes unavoidable. Be prepared to break or scratch or gouge some crystals. Sometimes breakage occurs with any crystal installation method. The goal is to make that occurence as infrequent as possible. Some of these installations may be salvageable with polishing.


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## pithy

G & S Catalog links:

GS Supplies - Watch Crystals & Supplies Catalog


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## pithy

BB Crystal Catalog courtesy of Mark:

http://www.watchandjewelrysupplies.com/PDF/BB_Reference_Book.pdf


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## constellation90

Crystal lifts are Ok, but I usually reach for the crystal press. Some watches it's an absolute necessity, as the bezel angle doesn't have enough room to fit a lift on. Watches like Rolex's it's also a necessity as you need to use it to squeeze the bezel back on around the crystal. A press might be a little harder for a novice to use, as you can quickly crack a crystal with the wrong chuck and too much pressure. 
If your going to get a press look for a vintage GS or one with nice soft plastic chucks.


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## Ozme

Thank you for this thread! You mentioned that older non-round crystals are often glued on; what kind of glue should be used when replacing one of these?


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## Deli

Try GS hypocement, or any UV glue if it's a mineral one.


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## Samantha

G-S makes a crystal cement that is suitable for those type crystals.
Samantha


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## samanderson

The info about the crystal press for acrylic is very helpful. I had only ever seen references to crystal claws - which I own and use - but have found that it often/usually leaves little marks on the crystal. I had wondered how professionals do it without leaving marks, and now I know. Makes a lot of sense really, and I'm glad I came across this thread. Thanks!


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## onewatchnut

The crystal press is the only way I know of to install plastic crystals in the bezel of a hunting case pocket watch. Although the cabinet model is the best, small bench versions appear on eBay quite often.

However, the bezel must be heated so it expands when installing a glass one (easily broken BTW).


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## denmarker

pithy said:


> BB Crystal Catalog courtesy of Mark:
> 
> http://www.watchandjewelrysupplies.com/PDF/BB_Reference_Book.pdf


thanks for sharing this. just what i need to last the night...


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## jcoffin1981

I bought a Sternkrautz press for a fair price. However, I prefer the Horotec press. I replaced some of the dies with tapered Bergeon ones. I like the control the threaded press gives vs. the lever style.


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## scheissestadt

Noob seeking some advice here, ideally from users with some crystal-fitting experience:


Short(er) version of my question:

I have two Junghans Max Bills, a 38mm auto 3-hand and a 40mm auto chrono. I would like to be able to replace the crystals myself on an ongoing basis with generic counterparts, using just a crystal lift tool. Is this reasonably doable for someone with currently no experience, or just a pipe dream? Assume the following:

- I will have found generic replacement crystals that are acceptable to me aesthetically
- I am willing to pay for a quality lift tool (Bergeon?)
- As long as there is a reasonable chance of success, then I am willing to risk the possibility of screwing up and ruining my watch
- It is OK if water resistance is compromised, as long as the replacement can still handle occasional splashes from handwashing and raindrops 


More detailed color:

I love the Max Bill designs, but have found the domed plastic crystals to be very fragile, especially on the 3-hand, where a light tap on the edge has created bubble fractures twice within a few months. The chrono crystal seems less fragile, but still it got a small linear crack from a moderate edge bump against a relatively soft plastic chair armrest.

It is at the point where I cannot enjoy wearing the watches, since these blemishes bug me and I really don't want to send them in multiple times a year @ $100 a pop. Resale value is poor and far outweighed by my appreciation for the watches, at least in theory. If I could switch out the crystals at will via lift tool then that would be ideal, even if the shape is not exactly like OEM and the water resistance is minimal. I'd rather not have to open the case back or deal with gaskets (front or back), although I'm open to that if it's necessary and reasonably doable for an amateur.


Thanks in advance!


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## pithy

scheissestadt said:


> Noob seeking some advice here, ideally from users with some crystal-fitting experience:Short(er) version of my question:I have two Junghans Max Bills, a 38mm auto 3-hand and a 40mm auto chrono. I would like to be able to replace the crystals myself on an ongoing basis with generic counterparts, using just a crystal lift tool. Is this reasonably doable for someone with currently no experience, or just a pipe dream? Assume the following: I will have found generic replacement crystals that are acceptable to me aesthetically I am willing to pay for a quality lift tool (Bergeon?) As long as there is a reasonable chance of success, then I am willing to risk the possibility of screwing up and ruining my watch It is OK if water resistance is compromised, as long as the replacement can still handle occasional splashes from handwashing and raindrops More detailed color:I love the Max Bill designs, but have found the domed plastic crystals to be very fragile, especially on the 3-hand, where a light tap on the edge has created bubble fractures twice within a few months. The chrono crystal seems less fragile, but still it got a small linear crack from a moderate edge bump against a relatively soft plastic chair armrest.It is at the point where I cannot enjoy wearing the watches, since these blemishes bug me and I really don't want to send them in multiple times a year @ $100 a pop. Resale value is poor and far outweighed by my appreciation for the watches, at least in theory. If I could switch out the crystals at will via lift tool then that would be ideal, even if the shape is not exactly like OEM and the water resistance is minimal. I'd rather not have to open the case back or deal with gaskets (front or back), although I'm open to that if it's necessary and reasonably doable for an amateur.Thanks in advance!


Crystal lift - Bad.

Inserting tool - Good.


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## scheissestadt

pithy said:


> Crystal lift - Bad.
> 
> Inserting tool - Good.


Can you please elaborate?

I see your point from earlier in the thread but unless I'm mistaken, crystal lift is the only way to do it without removing the case back and movement. I have seen lifts used successfully so it isn't black and white. Why would a lift be inadequate in my use case?


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## pithy

scheissestadt said:


> . . . . I have seen lifts used successfully so it isn't black and white. . . .


Are you sure?

Can you post high resolution photos of the finished product where the teeth engaged the crystal?


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## scheissestadt

pithy said:


> Are you sure?
> 
> Can you post high resolution photos of the finished product where the teeth engaged the crystal?


Sorry, I don't have pictures but I'm sure, at least for this use case. Whether I can reproduce those results is another matter.


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## Timemachine.fi

Great thread!


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## samanderson

scheissestadt said:


> Can you please elaborate?
> 
> I see your point from earlier in the thread but unless I'm mistaken, crystal lift is the only way to do it without removing the case back and movement. I have seen lifts used successfully so it isn't black and white. Why would a lift be inadequate in my use case?


Hey, it's been a while since you posted your question and you may have sorted it all out. But for what it's worth, I think Pithy's response is (obviously) a little simplistic. I have changed several crystals using my rather cheap crystal lift. For the number of times you intend to do it it hardly seems worth investing in a more expensive press. I took a watch to my local watchmaker just before Christmas, and he was using a crystal lift.

You do have to be careful about scratches from the claws, and some will be easier than others. But if the crystal has quite steep sides and sits high then it should be fairly easy. And the crystals themselves are cheap so you can afford to muck it up a few times anyway.


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## scheissestadt

samanderson said:


> Hey, it's been a while since you posted your question and you may have sorted it all out. But for what it's worth, I think Pithy's response is (obviously) a little simplistic. I have changed several crystals using my rather cheap crystal lift. For the number of times you intend to do it it hardly seems worth investing in a more expensive press. I took a watch to my local watchmaker just before Christmas, and he was using a crystal lift.
> 
> You do have to be careful about scratches from the claws, and some will be easier than others. But if the crystal has quite steep sides and sits high then it should be fairly easy. And the crystals themselves are cheap so you can afford to muck it up a few times anyway.


Thanks! Yeah, I have sorted it out since then--I got a Bergeon lift and have ordered some generic crystals that fit, and it all works well. I do somewhat miss the original Max Bill dome, which as far as I can tell is a closely guarded part that you can't just buy off the shelf. Every generic high dome I've tried has a more square profile, not the gradual slope of the OEM. But they're still good enough for my normal usage and there's a peace of mind knowing I can replace at will.


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## samanderson

scheissestadt said:


> Thanks! Yeah, I have sorted it out since then--I got a Bergeon lift and have ordered some generic crystals that fit, and it all works well. I do somewhat miss the original Max Bill dome, which as far as I can tell is a closely guarded part that you can't just buy off the shelf. Every generic high dome I've tried has a more square profile, not the gradual slope of the OEM. But they're still good enough for my normal usage and there's a peace of mind knowing I can replace at will.


Good work! How good is it to take a bit of a risk, give it a crack, and find out that you can do it yourself? It's not for everyone, and especially not on high end watches, but for me, it's all part of the hobby.


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## jdrichard01

I made a video a while back on installing a PW crystal and I used a G-S Press

Sent from my GT-N5110 using Tapatalk


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## jdrichard01

Sent from my GT-N5110 using Tapatalk


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## pithy

jdrichard01 said:


> I made a video a while back on installing a PW crystal and I used a G-S Press





jdrichard01 said:


>


It's a BEZEL.

You seem to be attempting an INSERTION.

Properly sized, NO GLUE is required for retention.


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## jdrichard01

pithy said:


> It's a BEZEL.
> 
> You seem to be attempting an INSERTION.
> 
> Properly sized, NO GLUE is required for retention.


Just stupid that day. I always glue in the crystals.

Sent from my GT-N5110 using Tapatalk


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## ArchieGoodwin

"Deleted double post" 

Eric


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## ArchieGoodwin

I would greatly appreciate if someone could cover crystal insertion with "armored" or tension ring crystals. How does one deal with the addition of the tension ring. I currently own both an older Bulova crystal press, and the G&S with nylon blocks. 

Eric


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## ururk

lysanderxiii said:


> These days there are basically three types of ways to fit a crystal. Each will require its own specialized techniques to properly install. (Removing can usually be accomplished by pressing with the thumbs on the inside&#8230
> 
> *1) Friction fitting
> *
> 
> 
> 
> 
> 
> 
> 
> 
> 
> This is the method almost all quality sapphire and mineral glasses are installed. The gasket (11) is normally a hard nylon or similar material, and can be either "L" shaped as shown or "I" shaped. The case has a slight undercut or angle cut in the vertical wall so the gasket will flow into it and lock itself in place. Simple friction between the glass and the gasket holds the glass in place. The size of the gasket is critical in the fitting of this type, it has to be the right thickness and the right diameter. To install you need a press that pushes on the outer edge of the glass or uniformly over the entire surface, and the press face and the case need to be parallel, otherwise the glass will become cocked.


Could someone expound on this method a little more - specifically how to calculate the angle, and so forth? If there is a book reference I'll gladly look it up.


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## Anthony

I believe Chapter 2 left and right in title are mixed.


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## slyc7724

Would someone add how domed acrylic crystal heights are to be measured. Is it the inside height from the bottom edge face to the inside of the apex of the dome or are is it to the outside and you need to subtract the thickness to get the inside clearance? I've looked at a lot of GS and Sternkreuz catalogs and there are no nominal drawings with dimensions, just cartoons.


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