View Full Version : Patek Philippe Calatrava 3520D Replica modded with Domed Sapphire Crystal

02-22-2012, 07:47 AM
I have a Patek Philippe Calatrava 3520D replica with a 2 hand quartz movement. The quartz movement isn't such a major tell, since Patek did produce Calatravas with quartz movements, and in any case, the 2 hands mean that it's difficult to detect that it's quartz in any case. Having looked at several Calatravas from the same era, I noticed that most of them came equipped with a domed crystal, so I decided to embark on a mission to replace the flat sapphire crystal that my replica originally had with a domed sapphire crystal. So begins the journey...

The watch has a pressure fitted back, which was quite a pain to remove. I ended up scuffing the caseback, but was able to polish out the scratches using some Cape Cod cloths. Kapton tape is excellent for masking off parts you don't want polished (like brushed surfaces), and can be obtained for cheap from Dealextreme (search for "high temperature tape").

It had a 29.2mm flat sapphire crystal (measured using digital calipers) installed with crystal glue, which I was able to remove with a crystal press (from Harbor Freight Tools). I ordered a 29.2mm domed sapphire crystal by SternKreuz (from TwinCitySupply), and some UV crystal glue. Most domed sapphire crystals are only available in 0.5mm increments, except for the one from SternKreuz, but TWC only had one in stock, so I'll only be able to do this mod on one of my 3520D replicas. Anyhow, this is the 3520D in its component pieces.


The original residue from the old crystal glue was scrapped off, and I cleaned the surfaces using some rubbing alcohol. The domed crystal fell right in, and I applied the UV crystal glue using the syringe the glue came with, and it has the consistency of water. In any case, I applied a generous (perhaps too generous) amount in the small gap between the bezel and the crystal, and cleaned up the excess using an alcohol swab. The crystal glue was then cured under a UV lamp, and the excess glue was again cleaned off with more rubbing alcohol.

And now for some shorts of the watch with the domed crystal.


These are some side by side photos of the replica 3520D with the original flat sapphire crystal (left), and the new domed crystal (right).

Side view of the flat crystal.

Side view of the domed crystal.

Finally, this is a photo of a gen 3520D.


and some additional photos of gen Pateks, notice that the reflections suggest that the crystals are domed.


02-22-2012, 07:57 AM
Where did you get this watch? TD?


The Dude
02-22-2012, 08:03 AM
Nice work HB.

02-22-2012, 03:11 PM
Great work and beautiful masterpiece!

02-22-2012, 09:55 PM
Thanks for the comments. The watch is on the small side at 33.5mm across (not including the crown), and I originally purchased mine from Taobao.com, but the seller there no longer seems to have it.

The only current source I have been able to find is from diystorm.com:


Item: PHW:212

But this is not a trusted dealer, and I haven't purchased from them, so I can't vouch for them.

02-23-2012, 01:54 AM
Another view of the domed crystal.

A shot of the solid caseback. It has only a very subtle engraving at the bottom stating the model and gold hallmarks.

Some of the buckles I have on my Patek replicas.

This is the standard Patek Tang buckle, note that it is not supposed to have engravings on the outside, only on the inside (some replicas incorrectly have engravings on the outside).

This is a fantasy Patek deployant.

The actual Patek deployants have either the Calatrava cross, or the look of the Tang buckle. I've been unable to locate a replica Patek deployant suitable for the smaller Patek replicas. The ones I've seen are 20mm and 22mm across at the buckle end, which means that the strap is probably 22mm or 24mm across at the lugs.

In practice, I tend to just wear my replica Calatrava 3520D on a plain push-button double butterfly deployant.

02-23-2012, 09:56 PM
Congrats for a great mod. You should be very proud to have a mod that possibly no one else have.

What about the straps? Are they the regular rep straps or anything fancy?


02-24-2012, 06:26 PM
Congrats for a great mod. You should be very proud to have a mod that possibly no one else have.

What about the straps? Are they the regular rep straps or anything fancy?

Thanks. The strap is a glossy Teju Lizard strap, which works well with the watch as the glossy finish gives it a particularly dressy look, and it is only thinly padded, which goes well with the size and thickness of the watch. Replacing the strap on a dress watch replica is typically the easiest thing to do to upgrade the look and believability of the replica.