Cracked my Clarks

[ldegeneve]

Got a Clark's "vintage style" T19 for my MBW 5513 (old school). Pressing on the retaining ring,it just went Crack! Didn't want to sand anything since my service t19 works great with it. Anyone else had this problem?

[AsiadeCuba]

I had huge problem with my 1665. The Clark t39 was too big! Try ofrei.com

[highoeyazmuhudee]

MBW/MBK retaining rings run small. always need a bit of sanding in my experience.

[automatico]

Agree with HH.

My MBK '5513' crystal retaining ring was too small so I changed the whole thing out for a Clark/ST bezel kit.

 

If you have a precision digital caliper you can measure the OD of the crystal after it is pressed down on the case neck and compare it with the ID of the crystal retaining ring. Measure the crystal and ring in 4 places and go with the bigger crystal OD and smaller bezel ID remembering that the bezel will conform to the crystal a little bit if both are close to being true round.  

About .2 or .3mm difference between crystal OD and ring ID is usually Ok, much more may crack the crystal.

If you can push the retaining ring down with your fingers it is too loose.

 

Caliper check...measure something 5 or 6 times, it should be the same every time.

[dbane883]

i think the Clarks inner diameter is about 0.2mm shorter than gen spec, and the outer diameter is about 0.3mm wider than gen spec, so when the the crystal is initially pressed on, prior to the retaining ring, it is already way too fat. So once the crystal is on the case, it is about 0.5-0.6mm wider than the inner diameter of the retaining ring.   Normally, the retaining ring should slip on about 2/3 of way down the crystal prior to pressing, but in my most recent experience with the vintage T19 Clark's, the retaining ring just barely fits over the crystal shoulders...   I think these recent batch of clarks are off compared to the Clark's I've used a couple years ago.

[ldegeneve]

Definitely makes sense. Had the same experience as above, comparing Clark's to a service dome.

[JoeyB]

Gary Clark will stand behind anything you buy from him. Just let him know what happened, and ask him for help. 

 

That said, we are working with copies of 50+ year old watches. 50+ years makes for changes in specs, and we are using copies of those. I've had many gen 6542 owners tell me my insert snaps in the bezel perfectly, and a few others with the high end replicas say they needed to shave a bit. My retaining bezel/ring are made to gen spec, and fit the Clark's 25-116 as it's supposed to.  But when I took one apart to work on something, putting it back together the retainer was loose enough on the crystal that I could finger push it to seat flush. The acrylic crystals do have some 'flex' to them, and temperature makes for some contraction/expansion. And that crystal may have had a bit of 'wear' in the first press. The bottom line is that, especially for those of us building/repairing replicas, the need for slight adjustments should be expected. If it fits together perfect the first time, I likely did something wrong! 

[ldegeneve]

Ha, all good points Joey.