Tavannes watch crystal replacement

[doober]

Hi everyone! I am a newbie. I am currently working on a wristwatch that is very dear to me (my late grandfathers) and need some help in buying the correct watch crystal. I have a few photos with measurements below.  Could anyone identify the proper size and shape to order and suggest where to order from?

 

Thank you!!!

[mikepilk]

You need to remove the crystal before you can properly measure it.  If you take the movement out, it should easily push out from the back. 

Then measure it across several diameters (without compressing it) to get an average reading. If you use the other end of you micrometre to measure the hole, the crystal should be about 0.2mm to 0.5mm bigger.

If you are in the UK, try Cousins : https://www.cousinsuk.com/category/acrylic-round-domed-watch-glasses

I would probably pick the Low Dome SternKreuz. 

You will almost certainly need a tool to fit it. 

[doober]

Mikepilk, thanks for the great info and quick reply!

  I live in the US -any suggestions on where to buy the crystal from? I am reluctant on using ebay because the Crystal's sold are vintage.

I will remove the crystal, measure it and order a low dome SternKreuz accordingly -thanks again for the explanation! I have a crystal remover/lifter/inserter tool (a cheap version not the bergeon) and I hope that it will do the job...

[GuyMontag]

I bought this assortment from Watchmaterial.com. It comes with sizes from 27.8mm to 32.4, 10 crystals for each size and they increase in size by 0.2 mm, so it comes to 244 crystals for $45 or about 20 cents each.

[mikepilk]

2 hours ago, doober said:

Mikepilk, thanks for the great info and quick reply!

  I live in the US -any suggestions on where to buy the crystal from? I am reluctant on using ebay because the Crystal's sold are vintage.

I will remove the crystal, measure it and order a low dome SternKreuz accordingly -thanks again for the explanation! I have a crystal remover/lifter/inserter tool (a cheap version not the bergeon) and I hope that it will do the job...

I believe that in the US, Esslinger and Jules Borel are the main parts suppliers. The acrylic crystals are surprisingly cheap (about $4), so I often buy a couple and use the most appropriate. The other can add to your store for future use.

I had a cheap version of the crystal tool. It worked sometimes, but often the teeth weren't sharp enough to hold the crystal. I got frustrated and bought a second hand Bergeon tool from ebay.  I hope yours works OK

Edited January 4, 2023 by mikepilk

[doober]

Thanks guys!!!!

[doober]

This watch has been a challenge for me to open...I was able to open (pop off) the watch back with a tool. The back was completely flush with the case except for a small point where previously (watch service years ago???) created scratch marks with some denting (minimal -had to use my eyeloupe) in the back could be seen. I used a tool very carefully and was able to pop it off. The watch is top loaded, so I cannot remove the movement first and pop the crystal out from the back.

The challenge:  The watch crystal bezel is completely flush with the case. Any suggestions on how to remove the bezel. I looked at the stem hole and I believe that it might be open to the bezel, but I don't want to bend the case If I attempt on pushing the bezel through the hole with a screwdriver without getting some advice first. pictures below. Thanks in advance!!!

 

 

 

 

[mikepilk]

It looks like this ring should be removeable from the back? 

[doober]

Hi Mikepilk,

 

Thanks again for the thoughts and quick reply!

I removed the red screws marked earlier. The yellow pointed ring did not budge and appears to be welded to the case? I was scared to use any force. thoughts?

 

 

[mikepilk]

Maybe it's just the lighting, but it looks like a gap in the bottom left corner.

The other option is to use your crystal lift to take the crystal off, push the movement out, and then you can have a close look at the case.

[doober]

I never sent you a picture of the back end of the watch while closed (never took one), but it is a snap on and the yellow marked ridge is the only area that the back could snap on to, so I believe that it is would not be a removable ring? Do you agree with my thoughts? making the crystal removal with the cheap tool the best next step? Thank you again!!!

[Marc]

I'm wondering if this is a 3 part case. A back, a mid-case, and a bezel. If so then the bezel should separate from the mid case as show by the arrow below. The photos aren't clear enough to be sure but if so then the movement will stay in the mid-case and the crystal will come off with the bezel.

[doober]

maybe this is a better picture, used my wifes iphone (yes, I am an android user,lol). It is a 3 part case, but the bezel is flush with the case. Anyone ever opened a tavannes wristwatch? Thank you all for the help!!!!

[mikepilk]

21 minutes ago, doober said:

maybe this is a better picture, used my wifes iphone (yes, I am an android user,lol). It is a 3 part case, but the bezel is flush with the case. Anyone ever opened a tavannes wristwatch? Thank you all for the help!!!!

 

A better pic would be angle down slightly, so we can see the gap between bezel and case.  

Is it definitely a separate bezel? If so, there should be a gap where you can insert a tool - can you see it?

If it is a bezel, and there isn't much of a lip, I start them of using a razor blade (careful!) - push it in to the gap and work it around the case. One there's a bit of a gap, you can push the case opening tool in.

[doober]

Mikepilk!!!! Eureka,I removed it!!! I used the razorblade method you recommended!  I followed your instructions. I inserted the razorblade at one point and slowly worked it around one half of the case (boy was there a lot of gunk -60 years worth, lol) and it popped off! I was nervous, my wife thought I was crazy standing at the window wearing a loupe (to minimize any scratching if any at all) with a razorblade in my hand, lol! Thank you for walking me through this procedure!!!

After further inspection it seems that there is no real gap, so patience is required and gunk does not help, lol.