Thanks for visiting my vintage Hamilton watch blog. I like to restore US-made Hamilton wrist watches back to their original glory and share my experiences with other enthusiasts. Use the "Search" space below if you know what model you're looking for. Feel free to leave polite comments or questions in the spaces provided. Also check out my "watches for sale" on my Etsy site - the link is on the right, just below.

Wednesday, July 25, 2012

How to Install a Watch Crystal

It's amazing what an improvement a fresh watch crystal makes to liven up an old watch.

The watch crystal serves a very important purpose.  Beyond just providing a clear perspective of the dial, it also protects the dial and hands from the damage and can be an important design element by including facets, bevels or magnifying windows.

Crystals come in three basic materials... plastic, mineral glass, and synthetic sapphire.   Plastic crystals are inexpensive and easy to install. They're easily scratched but it's also easy to buff out surface scratches.  Mineral glass crystals are slightly more expensive and more difficult to install.  They are harder to scratch but once scratched they can't be buffed out.  Sapphire crystals are much more expensive and may require specialized equipment to install.  But they are very hard to scratch - which is why they are used on most high-end modern watches.

Crystals on vintage watches are easy do-it-yourself projects if you have an interest to tackle it.

Take for example this 1931 Hamilton Perry.  Not only does it need a new crystal, it also needs a new number 1 hour marker (we'll save that for another day).

Putting the old crystal next to the new crystal is a good way to demonstrate just how different a new crystal will look.

Looking through the old crystal offers an even better perspective.

So your first question is probably, "how do you get the old crystal out?".  Sometimes it's already loose and you can just push it out with your thumb.  But most of the time they are not loose.

Non-round crystals are typically glued into the bezel with either a "cement" or "UV-curable glue".

Round crystals are often friction fit (principally the acrylic / plastic kind) where the diameter of the crystal is ever so slightly larger than the bezel opening.  A special tool is used to remove and install those crystals.

For a non-round crystal like on this Perry, it's glued in and if it's not loose you can free it by either (a) boiling it in water for a minute  or (b) put it in an ultrasonic jewelry cleaner for a couple of minutes.  Both ways will do the trick.

Once it's out, you can get down to business.  The next step it to make sure to remove any left over glue in the bezel opening by using a sharp tooth pick.  Avoid using anything metal to scrape out the glue - as one small slip will scratch the bezel and you don't want that.

If you're really lucky, the new crystal fits right into the bezel.  I don't seem to get that lucky though and 9 times out of 10 the new crystal is too big for bezel opening in which case you'll need to do a little shaping.  As you can see in the photo below, this crystal doesn't quite fit.

Now one thing to keep in mind is the crystal should fit smoothly in the opening.  Too loose is better than too tight.  Avoid the temptation to try to "press in" a crystal that almost fits... it's guaranteed to crack on you.  Take the extra 5 minutes to shape it a little more so it fits just right.

I find the best way to shape crystals is with 600 grit sandpaper - available at most hardware stores.  Plastic crystals are easiest to shape but glass crystals are shaped this way too - it just takes a lot longer.  All you need to do is put a few drops of water on the paper and work the crystal back and forth along the edges.

Take your time and work each edge until the crystal fits nicely into the bezel opening.

Now you're ready to glue the crystal in.  The type of glue really depends upon the type of crystal.  As a general rule, plastic crystals are installed with crystal cement and glass crystals are installed with UV glue.  I think both will work on either but they're best used if applied like above.

UV glue will cure in the sunlight, if your wondering where to find UV rays - although there are inexpensive lamps that ladies use to cure fingernail glue that you can use too.

Cement smells a lot like the glue I used as a kid to make model airplanes and cars... if you did the same you know what I'm talking about.

For this crystal I used cement...

You need a steady hand and definitely DO NOT ATTEMPT THIS WITH THE BEZEL ON THE WATCH. It's an absolute certainty that you'll get the glue on the dial and that's not a good idea.
A fine bead is all you need and you can spread it more with a toothpick if needed.

Once you insert the crystal the glue will probably squeeze out.  You can clean it up with a soft cloth and rubbing alcohol.

If you make a mess of it don't despair.  Just take it all apart, clean it in soapy water, dry it and start over.  You'll get the hang of it eventually.

Once it's all dried you can put the bezel back on the watch.

Now you can compare the before and after.

Changing crystals is an easy and rewarding project.  It's definitely something you should be willing to try now that you know how to do it!

Now to find a number 1....


  1. Can you believe it! First time I replaced a crystal was last weekend - for a YGF / AGN Perry! Wish I'd seen this page before because I thought I had to take the movement out; didn't realise it was a three piece case. Managed to lose one of the two case screws in the process - oh well. Thanks Dan!

  2. After reading this I went and bought a shiny new crystal for my 1935 Hamilton Cabot. Good thing I read this first, the crystal was a tiny bit too big. It would have probably been just enough to crack it, but I sanded it like you said and wala perfect! Now all I gotta do figure how to clean the dial, I could not find anything, so after trying to clean it, now it's also missing a 1 (Murphys law) it's the other half of 10. and the dial still looks bad. Crystal looks good tho.
    Thanks for the great info

    1. The first rule of dial cleaning is never mess with one unless you're willing to get it refinished. Of course, everyone messes up a dial at some point. All is not lost, it can be restored for less than $50. Email me for more info. You can reach me through the watches for sale page.

    2. Is it still less than $50 to restore a dial? I just bought 2 Hamiltons... 1 with a face that was a little spotted. I cleaned it, and cleaned half of the face off... The other's (Hamilton Sherwood) crystal fell out while I was cleaning it, and shattered... Sometimes you can't win for losing!

    3. Depends on the dial but the cost is in that ballpark. Never clean a dial that you're not sure you want to get refinished - no matter how tempting.

  3. I have a vintage womens Hamilton and diamond watch. It is not working and needs restoration. Can you help me? Do you have an email address? Lisa Young

    1. You can find a local watchmaker in your area on the AWCI.com website. Or you can email me through my Etsy shop or "contact me by clicking here" in the above right.

  4. How did you do with the number 1? I have a similar problem with a Hamilton of mine.

    1. Numbers are held on with little posts, or rivets. They are easy to remove and replace. A little UV glue from the back will hold it in place. So I just took a 1 from a scrap dial. Problem solved.

  5. Hello I have a vintage Enicar watch under repair. It has a plastic/acrylic crystal that is cracked (very slightly not too noticeable). The options are to leave it like that or replace it with a tailor made mineral glass, although they say that due to the thickness of the glass there might be a magnifying glass effect. What would you recommend?

    1. Assuming it's not round and you want glass, then a custom cut crystal might be needed. If you email me (through Etsy if needed) I can tell you where you can get that done.

      If the watch is round then getting a replacement is easy.

    2. Thank you, I'll e-mail you; the watch is not round, it's square face; basically the watch repairman said he can get a custom cut crystal, but my concern is if you think replacing an acrylic crystal with a mineral crystal works fine.

    3. Sure - as long as the crystal doesn't interfere with the hands it should be fine. I don't know why you'd have a magnifying effect unless the crystal varies in thickness.... thicker in the center than the sides. I would think that could be avoided but I don't have experience with cutting crystals.

  6. Excellent page. I've got a Hamilton Boulton. It's not an old vintage model, but it's still one of my classics, about 25 years or more old and quartz. I'm afraid that I cracked the crystal changing the battery. Especially irritating in that I've changed batteries in this watch several times. Oy. Will I need to take out the movement to change this crystal? (I hate to ask, but I don't want to open it back up just yet.)

    Thanks. And great page.

    1. Yes, probably. I suspect you'll want remove the movement so you don't get any glue on the dial.

    2. Just getting back to this. I have a new plastic crystal coming from Ebay, and I'm getting psyched up for taking this task on. Thanks for the help.

  7. So glad to find your site. Using it I've identified my watch as a Hamilton Linwood, engraved 1938 on the back. the crystal was chipped when I got it, and fell out a while back. Now knowing the model I was just able to order a NOS one on ebay. I'm thinking of having the dial refreshed or refinished. Do you do this or should I find someone, or could you recommend a place. I'm in NJ or could mail it off. thanks!