Crystal replacement

It’s an embarrassing early hurdle to hit in my very slow and minor attempts at watch repairs but I can’t for the life of me get a crystal in place without it shattering. I’ve tried two different watches, ensured the crystal is correct, researched the technique on countless sites but every time, pop!

Is it likely to be due to the press I bought? I admit I went for a cheap one of eBay but didn’t know if it was going to be unnecessary to overspend due to it being such a basic principle.

I’m seating the watchcases on large enough adapters for them to sit without resting on the lugs, am ensuring the gasket is pre-placed inside the case, am ensuring the upper adapter is slightly over the size of the crystal to enclose it, am pressing slowly but firmly but have now broken three. Gah!

Does anyone have any idea what I could be doing wrong?

Thanks in advance.


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Without a LOT more detail no-one’s going to help you.

Even though I completed some BHI training courses in 2010 I learned nothing about changing crystals, I’m totally self- taught.

A lot of it us down to common sense, if you’re dealing with mineral or sapphire crystals that fit in a gasket it’s essential to get the correct size of replacement, these glasses are sold in 0.1mm increments and you must get the correct size, a good quality digital calliper will help with the measuring. If you can’t be certain of the size buy 2 or 3 in different sizes and choose the one that fits.

Acrylic crystals are totally different, tension ring crystals are supplied in 0.1mm incremental sizes for around £5 each, the correct size will press in using a crystal press without excess force, but sometimes you have to buy 3 to get the right one.

I’ve spent more than enough time replying, if you want more advice you must give more info, lack of info is laziness on your part! Don't be fooled by u- tube videos, they always make things look far easier than they really are.

It would help to know the watch you are repairing, as there are different types of crystal, case attachment, ways that crystals fit, gasket, retainers, and crystal profiles and thus different techniques. For press-fit, there are some useful guides here: https://blog.esslinger.com/how-to-us...atch-crystals/

Most obvious likely issue if you keep breaking press-fit ones is that they are the wrong size, material or shape for the case and gasket.

@walkerwek1958 Thanks for the advice.

@Tokyo Tokei Thanks very much for your thoughts. The two watches that I've tried were a Seiko 7S26-0060 and a 7N43-8001. I've been re-using the same gasket as they seem in good shape with no nicks or stretching, so that shouldn't be causing an issue. The crystals weren't genuine Seiko but were listed as for the watches named. Thanks for the link to the site. I'd been looking through those videos just yesterday so appreciate your pointer to a good source of information. Thanks again for your time and help. I'll order another and see if I can work out where I'm going wrong!

I haven’t tried those particular models, although I have replaced the crystals on plenty of 7S26 SKXs with various aftermarket replacements. They just pressed in from the top, and I reused the gasket too.

Hard to know what’s going wrong if you have broken three, on two different models. When do they break? Immediately as you apply pressure, or do they appear to seat correctly and then break as you push them into the case?

If you put the original crystal back, does that work? If so, your aftermarket parts may just be the wrong type. There are hundreds of 7S26 Seikos, for example, with different cases.

Hope you get it sorted eventually.

Thanks again. Yes, it’s as I apply pressure once they’re all lined up. I’m clearly doing something wrong so will order another and try again! Watching videos such as the ones you mentioned, it clearly should just slip into place. Fingers crossed for round four!


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Be wary if the glass is thin much easier to crack them, any thing under 1.5mm likely to crack under huge pressure, also use a crystal die as large a possible.

Thanks Bry1975. Good tips. I just need to get my first one in and then I’ll know it’s possible!


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Why not practise with a 2mm or 3mm generic the 3mm wont crack easily.

Try putting the crystal in the freezer overnight and heating the case (and gasket) with a hairdryer before attempting to fit the crystal. Put a smear of silicon grease around the crystal and inside edge of the gasket to help the crystal ease in when pressed.

Terry

Excellent ideas. Thanks very much, both. I really appreciate the advice.


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