How to replace a broken watch crystal

It happens.  You’re wearing your watch, and oops, bang against something or accidentally drop it on a hard surface.   Crack – the crystal breaks.

I see broken watch crystals in my store every week.  These types of watch breaks are very common, and for the most part, easily repaired.  In some cases, however, they can be much more difficult on certain shapes of watches.  We will cover that later in this article.

The video here, shows you how to change a watch crystal.  Whether you are doing it for yourself, or you’re repairing a customer’s watch, this is how we do it in the watchmaker’s world.

So, lets get started.  You’ll need a few things to get the watch crystal replaced.  This class is specific to a round, flat mineral glass watch crystal.  These are the most common types of watch crystals, ad about 80% of all watches use flat round crystals of some sort.  The balance of crystal shapes may be square, rectangular, dombed or even oddly shaped.

In this course, we well be using the following tools…

  1. Screwdrivers
  2. Magnifying headset
  3. Hand Blower
  4. Millimeter Gauge
  5. Tweezers
  6. A Crystal/Case back press
  7. Rubber or Raw-hide Mallet

The supplies we will need are…

  1. Correct Size Replacement Crystal

To start, clean off your bench, or table top.  It is best to have a watch pad, but if you don’t, you can use a thick cloth.

If the watch band is leather, and you can spread it apart, good.  If it is a metal band, or a “closed loop” band, remove a pin or screw from the band to allow you to open it up so that you have clear access to the back of the watch.  In the example here, we have a closed loop band, which I remove a pin from the buckle so that I have unfettered access to the inside of the watch.

Next, either use a pry tool or a screwdriver to open up the back of the case.  Remove the screws with tweezers and put them aside being careful not to squeeze too hard with the tweezers making the small screws pop out and potentially getting lost.

Once the case back is off, put it aside.  If it was screwed on, put the screws on top of the case back so as to keep them all together, reducing the risk of lose.

Since we are dealing with the most common type of watch, a quartz watch here, we’ll stick to the details of this type of movement and case holder.  Further in this article, I’ll cover some of the other situations you may run into trying to remove the movement from the case.

In this example, there is a white plastic ring, which holds the movement firmly inside the watch case.  Also, there is a small metal ring, which adds weight to the watch.  That is its only purpose, as the watch case we are servicing here is plastic and light weight.  The metal ring is added to basically add some “heff” to the watch.

Most quartz watches have a small hole, with an arrow pointing at the hole.  This is the clutch release for the step.  Inside this small hole, you should see a little armature with a dimple in it.  It may be slightly different, but most have this small dimple.  If you look into the hole and see it, good.  If not, pull the stem out to the first or second position away from the case until the dimple shows up.  Once you see the dimple, we can move on to the next step.

Using a very small screwdriver, insert the head of the screwdriver into the hole so as to make contact with the dimple.  Depress it lightly and simultaneously pull the crown.  If it doesn’t come out, press the screwdriver just a bit harder into the hole, but not too hard.  Eventually, the crown and step will come out.  Put the crown and step aside, as not to lose it, you’ll have to put this back during reassembly.

Remove the plastic ring holding the watch movement in the case, as well as, (in this case) the metal ring.  Put them aside.  Gently flip the watch case over so that the movement and the watch dial come out of the case.

Now, we are going to move on to the meat and potatoes of this repair.

First, we are going to examine the watch dial for broken glass stuck in the dial, or between the watch hands.  First, use your hand blower to gently blow a bit of air over the dial.  Any loose glass should be blown off the dial.  Check to make sure that there are no broken bits of glass stuck between the hands or in the dial itself.  In the video, you’ll notice that before I took the movement out of the case, I put a fresh battery in the watch to make sure that it worked.  This help to determine if the watch movement was broken, if the hands move… All is good.  If the hands didn’t move with a fresh battery, this could be caused by a piece of glass that may have been wedged between the hands, damaging the small gears in the watch.  If this has happened, you’ll be changing the movement as well as the watch crystal.

Once all the debris is removed from the dial, place the movement aside and keep it from your working environment.

Now it is time to get the rest of the crystal out of the watch case.  We’ll start by getting our crystal press and finding the nylon discs that came with it.  You’ll see in the video I find a nylon disc that is a bit smaller then the diameter of the crystal, and place it on the bottom post.  I grab another small disk and place it on the top post of the crystal press.  Grab your nylon or rawhide mallet.  Place the watch, face up into the crystal press.  Pressing the handle so that the two nylon discs are making contact with only the broken watch crystal, use the mallet to gently tap the case of the watch, loosening the crystal free, and dropping the watch to the benchtop.

Get the crystal, and place it on your bench, along with the watch case.  Using your millimeter gauge, we are going to take two measurements.  First, we are going to measure the inside diameter of the watch case where the crystal sits.  Most of the time, you will be seeing a small nylon gasket in this location.  Measure the distance between the 3:00 and 9:00 o’clock locations.  If the crystal is mostly intact, measure the diameter of the crystal also, and compare the numbers.  In our case, it is 24 millimeters.

Get your new crystal, and lets get ready.

Make sure that on the watch case, or inside the watch case, there is no broken glass.  Blow it clean with your hand blower.  Get your crystal press, and find two larger nylon discs.  The first disc which will be placed on the bottom post of the crystal press should be large enough to hold the watch case flat.  The second disc should be just slightly larger then the crystal.  In this example, I’m replacing a 24 millimeter crystal.  The nylon disk will be 26 millimeters.  Place the crystal on the watch case, so that it is sitting elevated, but on top of the nylon ring in the watch case.  Place the watch on the crystal press, and make sure the crystal is centered on the case.  Gently press the crystal press so that the upper nylon disc makes contact with the crystal, and check that the crystal is still centered.  If so, depress the crystal press firmly so as to push the crystal into position in the case.  Do not press too hard.  The nylon discs can deform in the center, and crack the new crystal.

Remove the watch case from the press, and examine the watch to make sure the crystal is firmly in place, and flush with the top of the case.  If it is, clean the crystal with a good watch crystal cleaner and a lint-free cloth.  Once you are sure the crystal and case are clean, we’re ready to assemble the watch back together.

First, get the watch case, upside-down onto your bench.  Once more, blow it out with the hand blower to make sure that there is no debris in the watch.  Get the movement, and place it into the case very gently as not to damage either the hands nor the dial.  Turn the watch within the case to make sure that the small hole where the step goes through the case is lined up with the clutch position on the watch movement.  Get the step and crown, which should still be together, and gently push the stem through the case and into the movement.  Make sure that it clicks into position, and to test it, pull it out to the first or second position, and make sure it remains inside the movement.  If it does, great.  If not, repeat those previous steps.

Place the new battery into the watch, then take the plastic movement holder and put it back into the watch to hold the movement in place.  In some cases, you may have to put the movement holder in one side first, then push the other to place it properly.  If the holder does not go in without a fight, do not push on it.  Remove it and try again.  This piece will go into place without much of a fight, but we don’t want to cause any damage to the watch.  Flip the watch over, and double check that it is working.  Try pulling the step out one or two clicks to make sure all setting functions work.  If so, Great!

Place the watch face down again on the bench.  In this case, the video shows that weighted ring.  We’ll place that inside now.  The next step is to grab the screws and the back cover.  Put the screws aside, and place the cover back onto the back of the watch case.  If your case does not have screws, you may need to place it back into the crystal press to firmly close the watch.  In any effort, we are following the reverse of our disassembly procedures.  In our video, we’ll place the back onto the watch, place the screws in their positions, then tighten them down.

Double check the watch.  If it is still working… Great!

Now, lets make sure the band is put back together, and once done, the watch is ready to go back to the customer.

In my example, because the band was dirty, I opted to clean it and return it to the customer clean and ready.

That is it.  Round crystals are really easy.  In some cases, you may have an odd shape crystal.  One that you can’t get in may places.

I have had to send watch cases out to have custom crystals made, and this can be very expensive.  I remember once time I had a custom crystal made for a very custom watch, and the cost of just having the crystal cut to fit was over $300.00.

For the most part, replacement crystals for most watches can be gotten from their manufacturers if the watch had been made within the last five or six years.  After that, it is hit or miss.

Round, flat crystals, as well as common square and rectangular crystals can be gotten from most supply houses.

If you can’f find one, contact me, and I’ll see what I can do to help.

Thanks again…

Happy Fixing.

Peter

 

 

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