Seiko crystal replacement

[Bill3]

I broke the crystal in my Seiko wrist watch.  It is a flat round crystal and I have removed the broken one, measured it carefully, and have ordered and received a new one.  The problem is getting it in place.  I have tried many times to press it in by hand, without success.  I am reluctant to put it in a press for that seems a certain way to break it.  
Does anyone have a suggestion about how to get the crystal in? Also I would appreciate an opinion about whether or not the crystal should be cemented in place.  Thank you!

 

[watchweasol]

Hi  when you removed the broken one was there a gasket in the case if so you will need a press to refit it if no gasket it is possible it was glued in . There are may types of adhesive hypo cement, ultraviolet setting adhesives which as the name suggests uses UV rays to cure,  but first check for the gasket left in the case.

 

[jdm]

14 minutes ago, Bill3 said:

I have tried many times to press it in by hand, without success.

If there is a nylon gasket, it cannot be pressed in by hand. If there is no gasket, it must be cemented (uncommon since many years), and it's the wrong size because it doesn't fit. The only other possibility is that it's a tension ring type, but these are also a thing of the past.

On the watch caseback there is the refence number like XXXX-YYYY which using public sources will tell what is the Seiko P/N for the crystal. That among other things directly tells the size.

[Jack75]

I am today fitting replacement crystal (correct size) into a Pogue 6139-6002.

Even with a Horotec crystal press it turns out to need considerable pressure. Reluctant to grease the gasket as this could cause loss of the crystal later. Another one of the many Seiko crystal issues. Unless you are looking for authenticity I would use G-S Hypo watch crystal cement.

 

[jdm]

13 minutes ago, Jack75 said:

Reluctant to grease the gasket as this could cause loss of the crystal later.

Greasing a nylon gasket is never advisable or even helpful. When the interference is so large that the crystal won't go in normally, that's is like walking in thin ice area, which just like a watch glass do break easily.