More on the subject of PAM rep crystal installation...

[w0lf]

Good news everyone!

So I get asked about this issue on a fairly regular basis, and I don't think that bumping my older threads is a good way to alleviate the confusion on this subject. The truth is always somewhere in the middle and this is no exception. This is a long read, for which I apologize, but maybe you'll find something that you didn't think of before. I'm going to combine from several of my posts and private discussions so this may look familiar to some of you. The data is collected over a pretty sizable chunk of time, all first hand with my own tools, and I would estimate from close to a 100 watches or in that ballpark.

First some numbers and findings:

Crystal diameter on manual wind models (3.5mm center thickness):

o OEM Panerai 35.50-35.52mm

o Aftermarket/replica 35.49mm to 35.57mm

\_ this varies slightly, but more so on the plus side, e.g. I encounter a lot more 35.53mm crystals than 35.49mm ones.

Crystal I-ring gasket thickness:

o OEM Panerai - 0.56mm

o C3 - 0.56mm *

o Noob 111J - 0.39-0.42mm

o Noob 005/111/112/219M - 0.37-0.40mm

o Noob 005/112/111N v3 - 0.49-0.50mm

o H-F all models: L, K, M & N - 0.49-0.53mm

Crystal I-ring height:

o Between 1.00 and 1.25mm will work with any case crystal bed.

* C3 gasket is OEM size and thus will only fit a JimmyzFu or OEM case.

Secondly, you cannot underestimate the importance of using a good crystal press to do all of your installs. If you're a weekend warrior and can't justify getting a Bergeon or another good quality press, do not get the $15-25 presses from eBay with all-nylon dies. The following two presses are the next best thing on a budget - 1, 2. I recommend getting both as the dies are interchangeable and sometimes when you need a bit more oomph use an alloy die from the pliers press. Also, if you create your account on WatchBitz and then email Alan about getting a RG/RWG discount, he'll set you up so you see lower prices in your cart automatically.

If after reading this you feel this exercise is not for you, have someone with a good press install the crystals for you because guess what - there are no readily available gasket replacements anywhere. You mess up a gasket, you might as well toss the case. You may get lucky with some DSN or CousinsUK gaskets, for example Cousins p/n: IG363355C1 sometimes works in Noob 111J and 111M cases but there is never any guarantee either will fit in your specific case.

Reason for this is simple, though PAM reps are better today than ever before, we're still having all the same issues we had 8 years ago. The tolerances have gotten higher due to better machining, but we also have ten times more combinations of parts available. Multiple models from the two major factories came off different masters/molds, several crystal manufacturers have been employed along the way, and don't forget custom and boutique makers like C3, LH, JF, Taka, DSN, etc.

Moreover, there's an ever-present x factor, which in reality is nothing more than a combination of inconsistencies working against you. They are usually a slightly over-sized crystal, a slightly tighter than spec case rehaut, a slightly thicker gasket or not enough give in the gasket. To illustrate this better, stay with me through this exercise as the below scenario is common.

You are installing a H-Factory crystal in your new Noob case; the crystal happens to be 35.54mm instead of 35.50mm, your Noob case crystal bed is 36.25mm instead of the usual 36.30mm, BUT the gasket in your case just so happens to be 0.40mm on the nose. Result - you won't be able to install this one. Your gasket needs to be 0.22 to 0.25mm thick at the most in order to offset the tolerances on other parts. Once you start doing the math it becomes obvious why you have this issue: (35.54-35.50)*2 + (36.30-36.25)*2 = 0.18mm, that's how much thinner the gaskets needs to be for your crystal to fit. There are no gaskets that are that thin or can get squeezed that much.

Thirdly, and equally as important as all of the points above, you need to make sure that if you or anyone else took out your crystal gasket for any reason, when you go to put it back in the case - it's getting put back the right way up. In a perfect scenario your case has a proper spec. crystal bed, you have a mint original gasket that came with the case and you have a crystal that's not overly gigantic - 35.50-35.53mm. You go to instal and pinch and crease the gasket because you didn't check the orientation.

Pick up a jewelers loupe and take a good look at the inside of the gasket. What happens when the crystal is pressed in for the first time is the "I" gasket becomes squeezed into an "L" gasket. Some nylon gets pushed down and forms a tiny ledge that lives comfortably in the bottom bevel of the crystal. It's not hard to miss this tiny amount of extra nylon when you're replacing the gasket, but it makes all the difference. This ledge always needs to end up on the bottom.

To recap, for a successful crystal install the following are essential:

1) Original gasket that came with your case in good condition, no pinches, creases or flats.

2) Good quality crystal press with alloy or brass inlay dies.

3) Correct orientation of the gasket inside crystal bed.

4) Non-gigantic crystal is also a plus, I have a 35.57mm crystal sitting in my box, it's never getting installed.

In conclusion, it must be said that if you have all the parts in front of you, and you have a digital caliper precise to 1/100ths of a mm, it will take a minute to figure out if it's a doable job beforehand.

Thank you for reading and I hope I didn't bore you too much.

[redwatch]

Very fascinating read M! I would never have thought I should use the alloy dies when pressing in a crystal. I had always assumed that they were for press on case backs.

+1 on the Watch Bitz kit. I have a horotec style press but with all of the nylon and alloy die sets that Offshore offers and it is a great piece of kit. Cannot recommend it highly enough!!!

[w0lf]

Yep, as long as it's sapphire, there's no chance of scratching the crystal. Now, if you are in fact pressing in a double A/R crystal (which is just a noob factory inverion as OEM crystals are only single A/R coated) then use a neoprene or selvyt cloth over the crystal and stick with plastic dies.

[justlounging]

Wat a good read!!!

Thanks for taking the time to write this!

[RWG Technical]

Excellent write up.

Very detailed, easy to follow, all the items are covered in depth and you have provided insight on your experience and solutions.

Thank you for this, well done.

[Watchmeister]

Excellent write-up. And knowing this is coming from a person who has tried every combination this is invaluable information.

[dluddy]

Good stuff Wiolf. Thanks for taking the time to post this

[w0lf]

Thanks very much guys!

Projectologist made some cool photos that illustrate the gasket ledge beautifully, maybe he can post here.

[projectologist]

Here you go...

[paneraitom]

some great tag team stuff

[Ronin]

Great write up!.

For the record, I have never had an issue with DSN stuff. I used to have Chief do all my AR work on them, and they managed to go in and out, and even maintain water resistance without an issue.

[Ephry73]

Bump for an awesome post

[wimpie007]

Old topic but hope you also have specs about the 312/359 crystal size. Your PM box was full