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



Frank Adam wrote:
> 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

Right! :-)

- What may be done at any time will be done at no time. -
Scottish Proverb

.

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