Internet Horology Club 185
992B Crystal Question

This topic can be found at:
https://ihc185.infopop.cc/eve/forums/a/tpc/f/254108073/m/6871066481

May 16, 2006, 07:18
John Scott
992B Crystal Question
Could someone kindly advise me as to the correct size of crystal for my Hamilton 992B stainless steel case No. 15 - and a possible source of supply, please?


May 16, 2006, 19:02
Robert M. Sweet
John,
Below is a links that may be helpful.

Robert

https://ihc185.infopop.cc/eve/forums/a/tpc/f/2...981033841#7981033841
May 16, 2006, 19:12
Lindell V. Riddle

Hi John,

As you'll read in the topics Robert pointed to, they vary, not a definite size as such.

The acrylic crystal Peter mentioned in that first link is a perfect choice for your Stainless-Steel Cased 992B as it is in keeping with the rugged nature of the beast. Newly manufactured acrylics offer the same appearance as glass, they are of optical quality and can be polished easily to remove minor scratches.

Measuring for and then fitting the crystal are the only complications.

Lindell

Wink

May 17, 2006, 09:31
John Scott
Robert and Lindell

Thank you, both, for pointing me towards and for providing me with wise advice. I am able to do my own fitting but here in Australia it can be difficult (or impossible) to obtain materials. Nowadays, the internet is a great help, of course.

With thanks, again.
May 17, 2006, 15:03
Lindell V. Riddle

John,

To narrow it down for your Case 16 application, I'd want to have a 19 2/16 as well as 19 3/16 and 19 4/16 available. For the millimeter equivalent the 43.3 and 43.4 along with 43.5 should do the trick. Having those sizes and the ones just above and below them should cover most of the later RR watches. However, due to their incresing popularity, these are also the sizes that are becoming the most difficult to obtain.

For installation, my preference is to clean and fit the crystal, spin it to the tightest position, then mark both the bezel and crystal with a marking pen and remove it. At that point a light coating of L&R Crystal Cement in the grove quickly wiped of excess with your finger. Then immediately carefully "snap" the crystal into place as previously marked. Use of the cement eases the crystal into place and avoids edge-chips.

Not knowing your level of expertise I hoped this information might be helpful.

Lindell

Wink

May 17, 2006, 15:29
Peter S. Balkan
Very honestly, I couldn't imagine replacing a crystal unless I had access to a rather larger selection of stock.

Quite aside from learning the techniques (which are not so difficult), I seem to always miscalculate the size and actually find the right size by trial and error (most of the time).

Since the labor costs on crystal replacement should not be extreme, I'd probably recommend that most folks simply send their bezel to a well-stocked shop.
May 21, 2006, 21:42
Robert M. Sweet
Here we have a "Crystal Size Ruler" from a 1935 Material Catalog.

Are these hard to locate?

Robert


May 22, 2006, 00:56
Peter S. Balkan
In the best of all world's, Robert, I suppose we could simply measure the crystal size and order one.

But.... at least in my experience, it is not all that unusual to find that the bezel has been "worked" and is now difficult to fit.

And Hunters? I've come so close to finding crystals for hunters, only to learn that the dome was too high for the case to shut.... or the crystal was too low for the hands to clear.

I'll still go with trial and error.
July 04, 2006, 08:23
John Scott
To all who provided the kind and informative responses to my initial question I now report back.

I took the advice that the acrylic crystals of today are of sufficiently high quality and durability to grace a railroad grade watch and followed one of the leads to Twin City Supplies (with which supplier I had not previously dealt). There Joel Held provided excellent service, sending me a requested selection of nice bevel-edged acrylic crystals for my stock. From amongst them I have found that size 441 - 49 1/2 securely fits the Hamilton No. 15 stainles steel case and it certainly looks the part. I used my Swiss multi-pronged compression tool to enable me to slip the crystal into the bezel. Problem solved.

I would add that I am conscious that it was a requirement for standard watches in railroad service to be fitted with glass crystals and it is a fact that I utilise the watch in engine service on a tourist railroad. Even so, I think that the acrylic crystal will provide safe and satisfactory service.

Once again, my thanks to the good people of Chapter 185 for their ready assistance.

John Scott