Re: Nicest watches I've ever seen...

On 29 Jun 2005 02:49:27 -0700, "the swisswatchguy"
<swisswatchguy@xxxxxxxxxxx> wrote:

>> Having said all that, i'll check the case the next time one comes
>> across the bench, right now i'm just talking through the other
>> orifice, but it's ok, according to my wife, my brain is often just a
>> few inches in front of it somwhere..dunno what she means by that. ;-)
>>
>The water resistant plexiglass system was invented by Mr. Morf, EMO SA,
>based upon the certain elasticity of the material combined with an
>inside ring. The encasing of the movement/dial/hands was made from the
>top, with a forked two-piece winding stem. For those reasons, you could
>
No.
The Moon watch is not a one piece case and the stem is not a split
design. You're thinking of the Seamaster series, some of which indeed
had the two piece stem with the one piece case and with those, fitting
a crystal would make it hard for the average watchmaker to open them.

However, "hard" doesn't mean impossible and i bring to your attention
the Cosmic 2000. By the book you should use a pressure pump through
the case pipe to open those, by popping the glass off. Once that is
out, you can remove the movement towards the front and press the back
off with ease.
The difference is, that the Cosmic 200 case does open with just a
standard press, if done carefully and properly, while a one piece
Seamaster case of course could not be opened by anyone, not in
posession of a case pump if a crystal was fitted.

>not replace it with a domed sapphire crystal, which has no elasticity
>at all. It could however work with some special mineral crystal (which
>however is not scratchproof enough and cannot really be buffed
>properly).
>
The waterproofing of a watch case is not a problem if the crystal is
fitted (as i've said above) with a plastic gasket. There are plenty of
300M watches out there with crystals, even domed crystals using the
very same technology.
With a tension ring glass, such as the one on the Omega, the plexi
itself gets squashed between the case and the inner tensioner. Since
plexi is soft, it takes up the shape of the case to seal any small
cravices.
With a plastic gasket you achieve the same thing, except that it's the
gasket which is soft and it gets squashed between the crystal and the
case.
The plastic gasket also lasts much longer than a plexi glass, which
with time will become brittle and often when removed from the case
splits at the tensioner ring, showing off that while form the outside
it may have looked sound, it was on th ebrink of failure.
This won't happen with a quality plastic seal and crystal.

To sum up, in most cases where a tension ring glass is fitted, it can
be replaced with a combination of the plastic seal and crystal. The
wall design, where the glass sit in, is the same on both, that being
parallel. It is the waterproof (or high chevee) glasses which can not
be replaced while ratining waterproof quality, as the design of the
wall is angled, to compress the glass downwards after fitting.

So to restate, the only thing that will restrict the fitting of a
crystal to a Moon watch is the protrusion of the hands. If they come
up high, taking full advantage of the high plexi, finding a suitably
thick and domed crystal may be hard, perhaps even impossible. However,
as i remember the glass was not a particularly high glass.
And as i've said, until i get to see one again, i can't make a
definite comment on it, but as soon as i see one, i will let you know.

ps: Seiko even had stepped up crystals (shaped not unlike the tension
ring plexi), sitting into a soft rubber seal, but that one, due to the
thin side wall of the glass required to be pushed downwards, as the
sides couldn't take too much of a sideways pressure. That of course
would be unsuitable for any watch not having a top ring.

Hope that explains that.

--

Regards, Frank
.

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