Seiko SKX (clone) crystal gasket question (too big)?

[NewToWatches]

I purchased an empty aftermarket Seiko SKX-style case, which came with a flat crystal.  The goal here was to play around with various modifications, including a double dome sapphire crystal.   I popped out the flat crystal without any trouble, but the clear crystal gasket, which came out at the same time, just does not want to play nicely.  It just does not want to sit in the case mouth -- it is too large.  I have tried seating it by holding it in place and chasing the "bulge" around the opening.  But no dice.   On the other hand, somehow the OEM manufacturer got it in place. This may explain why the watch case did not test as watertight in a pressure tester.  

Any tricks for re-installation?  Or does it make more sense to measure the opening, go to Esslingers and order one that is the proper size.  I'm prepared to do that, but isn't the gasket just supposed to drop in?

Hints, suggestions, eye-rolls, all welcome.

[watchweasol]

Hi  If the gasket that came out does not go back cleanly the only option is to replace it especially if you require a watertite seal.

[NewToWatches]

Many thanks!  I feared as much, but wanted to ask before I spent more money.

[xyzzy]

Sometimes you can get away reusing them, sometimes you can't.  It's much easier to reuse them if they stay in the bezel.

The gasket is permanently squished when you install the crystal.  You can see the difference under a microscope.  I think this has the effect of stretching it, so it's now slightly larger in diameter and won't fit.

What I've been able to do is to make a inward bulge in part of the gasket.  This makes it smaller and it can fit, but you'll be left with this bulge that isn't pressed to the outside like it should be.  Then you carefully press the bulge out.  Sometimes this works, and sometimes you get a kink in the gasket, in which case it's done for.

It can help to use some sort of tool, like the sides of some tweezers, to try to mash the top edge of the gasket, while it's in the watch, to make a bevel.  To help guide the crystal in so it doesn't get hung up on the edge of the gasket.  I wouldn't do this to a new gasket.  They'll already have the bevel.

If you've tried to reuse the gasket and the crystal didn't go in straight and got jammed, then it's quite possible the gasket is damaged too.

I've tried heating the gaskets to make them more flexible.  Does not work.  Just makes it worse.  Maybe heating the case and freezing the gasket?  I haven't tried that yet.