Invicta Grand Diver glass crystal source

[LittleWatchShop]

I am replacing  this crystal.  It measures: 33.55 x 3.5.  I found a guy selling the crystal for this case in UK but after shipping it is over $30.

I can buy a 33.5x3.5 from several material houses in the US for cheap.  Maybe that 50um difference will not matter.

Thoughts.

[jdm]

14 minutes ago, LittleWatchShop said:

I can buy a 33.5x3.5 from several material houses in the US for cheap.  Maybe that 50um difference will not matter.

I don't know what the guy is selling, but there are no steps smaller than .10mm in the watch crystals industry, beside mass produced watches always use multiples of 0.50mm. Measure it again with a micrometer (calibrate before use), across two positions to confirm.

[LittleWatchShop]

7 minutes ago, jdm said:

I don't know what the guy is selling, but there are no steps smaller than .10mm in the watch crystals industry, beside mass produced watches always use multiples of 0.50mm. Measure it again with a micrometer (calibrate before use), across two positions to confirm.

Yes this is my understanding (0.5mm increments), as I have been schooled on this topic already.  Indeed, I do not know what he is selling either...other than genuine invicta crystal.

I will order one from Esslinger and see...most likely just fine.

[Nibbler]

I bought a crystal from Esslinger that fit perfectly in my pro diver. Here are the details.

Watch Crystal Flat Round Mineral Glass Crystal 3.5mm Thick (MM Size: 33.5)
Sku: 201350-33.5

I did a post on the repair:

 

Edited January 7, 2022 by Nibbler

[LittleWatchShop]

24 minutes ago, Nibbler said:

did a post on the repair:

I did a search here, prior to asking...not sure why I did not see your post.  Good work.  I will order same size from Esslinger.

[LittleWatchShop]

OK, the 33.5mm crystal arrived.  I installed it.  HOWEVER, it was a "soft" push.  I compare this to the other ones I have done (not many).  I imagine, that the additional 100 um might have been noticeable. 

Whatever, I told the owner that it might not make it to 1000 feet depth but probably make it through a shower!!  That was fine with him.  I mean...if something goes bad...he walks across the street and hands it to me...again!

[jdm]

13 hours ago, LittleWatchShop said:

 HOWEVER, it was a "soft" push.

Try pushing it out with your thumb. It you're able to, get a new gasket.

[LittleWatchShop]

4 hours ago, jdm said:

Try pushing it out with your thumb. It you're able to, get a new gasket.

Yeah...this is a tar baby.  Sure enough, I put the watch in the chamber to test and it leaks at the crystal as well as the back.  I need to get a new gasket and resolve the crystal issue.  I think that extra 100um is in fact the issue.

Regarding the gasket, I watched the esslinger video on replacing gaskets.  They say to measure the outside of the case back.  However, that does not seem right because as you can see in this picture, the gasket would naturally lay in that trough around the inside rim.

[jdm]

58 minutes ago, LittleWatchShop said:

 However, that does not seem right because as you can see in this picture,

Of course it is not (always) right. They are a material house, not repairers, and write these "instruction" to help owners wanting to do thing by himself, typically replacing a flat gasket without groove on the case.
A groove normally goes together with an O-ring gasket for diver's, but that should be confirmed measuring its depth.

[LittleWatchShop]

Ordering a new o-ring and new crystal gasket...I will report back when done

[LittleWatchShop]

On 1/12/2022 at 11:30 AM, LittleWatchShop said:

Ordering a new o-ring and new crystal gasket...I will report back when done

New crystal gasket arrived. Anything I can do to improve chance of not leaking...GS hypo, or something?

[jdm]

7 minutes ago, LittleWatchShop said:

New crystal gasket arrived. Anything I can do to improve chance of not leaking...GS hypo, or something?

Absolutely no, nylon gaskets are to be installed without any agent whatsoever. They hold by elasticity and interference. You can tell by the force needed fo fit if that is there or not. 

[LittleWatchShop]

7 minutes ago, jdm said:

Absolutely no, nylon gaskets are to be installed without any agent whatsoever. They hold by elasticity and interference. You can tell by the force needed fo fit if that is there or not. 

K. Will try

 

[LittleWatchShop]

So far...no luck.  Still leaks

[LittleWatchShop]

OK SOLVED!!!!!!!!!!!!

In a rather unconventional way.

Teflon tape!

Please don't throw me off the forum.  This watch is my neighbor's and he is a watch abuser.  He will break it again even worse...I am sure.  This will get him down the road a ways!

[jdm]

Very well, maybe the needed crystal was indeed 3.55. In my book, any repair that works, lasts and doesn't hurt the eye, is a good one.

[LittleWatchShop]

10 minutes ago, jdm said:

was indeed 3.55

So, I did a test.  I stacked the crystals up with the old crystal on top.  Then, using my precision calipers, I attempted to grab both crystals and lift.  Well, only the old crystal lifted.  Then while holding the old crystal with the calipers, I fit the new crystal with the calipers and could easily see daylight along the edge.  Indeed the original crystal is bigger...probably another scam--I found the crystal on the Invicta site for $38.