I need to find a replacement acrylic crystal for my PRS29A. The measurements are 32.4mm x 1.5mm. Does anyone have a source for one of these? I’ve looked around to no avail.
Silly question, but I`ll ask it: why does the crystal need replacing? Unless its cracked it should be possible to refinish it, even relatively deep scratches can be polished out using the correct techniques.
Assuming no genuine originals are available the only answer is to get a repair to fit a generic Sternkrauz crystal. I`ve never handled the original PRS29A so I`m not familiar with how the rehaut ring works in relation to the original crystal so I can`t advise further.
The reason is because I had the original cracked crystal replaced about two years ago. Unbeknownst to me, it was replaced with a 32.3mm, not the original’s 32.4mm.
I noticed recently that the inside of the crystal would fog up when washing the car etc. so I sent it in to my other watchmaker who says it’s leaking around the crystal.
I’m assuming the 0.1mm would make enough of a difference to allow air to get through but would welcome any thoughts.
Would have thought the ATC Sternkreuz 32.4 would fit, seems easily obtainable in the UK at least.
That should work. I can’t seem to find it in the US but will pick one up from Cousins. Thanks Ed!
If you get stuck I can post you one from the UK Redcoat.
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A very kind offer. Thank you, Crowsfoot. Will let you know if the Cousins route doesn’t work out.
Update on this, in case anyone is interested. My watchmaker has tried to install four correctly sized acrylic crystals and they have all cracked. He was able to install a domed sapphire which passed the pressure test.
However, the movement is now no longer working. I’m told the hands are not stuck or touching, balance swings freely but won't tick. The movement is at least five years old so I’m assuming a service or fresh 2801 movement is in order.
That doesn’t seem right (the crystals cracking I mean). I’d be inclined to try another watchmaker if I’m honest.Originally Posted by Redcoat
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I would double check the clearance between the hands and the crystal. I had the sapphire PRS-29A and wasn't keen on the milky ring, so I swapped the crystal for the acrylic Sternkreuz 32.4mm. However, didn't really like that either (I thought the dome was just a bit too high). I then decided to try a 31.5mm double dome sapphire (which looks great on my Hamilton Khaki 38mm no-date mechanical). It fitted no problem, but after re-assembly, the movement stopped. In my 'case', the second and minute hands WERE touching the crystal. At that point, I gave in and re-fitted the original box sapphire!
Only just spotted this. Duncan at Genesis Watchmaking was able to source an acrylic to my PRS29A, he used a 32.5mm acrylic as he found it was a better fit. It's been fine.
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