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Discussion Starter · #1 · (Edited)
I picked up a 1976 6139-8050 chronograph recently at a pretty fair price. The dial looks beautiful, but the crystal is covered in surface scratches. It's a pretty tough to find/expensive crystal I think (310W24GN), and I don't have tools or experience replacing a crystal either. If this is the original crystal it's hardlex, so it looks like a dremel and some dia-paste might get these out? I read lots of different options so I figured I'd post photos of my particular situation and see what the experts think :).

So, my questions are:

1. Is it worth trying a polishing pass with a dremel and some compound?
2. If not, is it possible/wise to replace it without exotic tools, just a case opener and holder?

Thanks in advance for any advise you can give!



 

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http://www.stsupply.com has the crystal for $22.

You could try polishing but it's going to be a pain in the ass.
+1. Unless you have the proper tools and experience, Hardlex is near impossible to polish out. Even with diamond paste its a tough job. What you end up with is a very shiny crystal, still with scratches. Either leave it as such or spring for the replacement crystal - $22 is fair. IMO the watch is worth the investment. Good luck!
 

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Discussion Starter · #5 ·
Thanks a lot for the quick replies (and nice catch on the model number typo, rob3rto)! I'll just snag a new crystal in that case and skip the polishing. Is it tough to replace? I'm not shy about small precise work, I do a lot of soldering and small surface mount electronics, but I'm new to this particular hobby and it's hard to know sometimes what jobs are in reasonable reach of a beginner.
 

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Thanks a lot for the quick replies (and nice catch on the model number typo, rob3rto)! I'll just snag a new crystal in that case and skip the polishing. Is it tough to replace? I'm not shy about small precise work, I do a lot of soldering and small surface mount electronics, but I'm new to this particular hobby and it's hard to know sometimes what jobs are in reasonable reach of a beginner.
You are going to need some tools to open the case back, remove the movement, remove the old crystal and then insert the new crystal. As a minimum you will need:
- Case Back Opener
- Tweezers
- Jewellers screwdrivers
- Crystal Press.
- Serious Sized Balls - if your fist crystal replacement is going to be a Chronograph!

There are casing instructions specific to this watch (6139-8050). It is an F-4 Screw-16

F-4 Instruction shows how to remove the Bezel.

Screw-16 defines the exact Disassembling Procedure through steps 1 to 10 (on the left hand side of the diagram) and then the Assembly Procedure through steps 1 to 10 (on the right hand side of the diagram)

F-4.jpg

Screw-16.jpg

Good luck!
 

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Discussion Starter · #7 ·
IMeasure, thanks so much. Really appreciate you taking the time to share that. That is more involved than I had expected. I also realized that since it's a chrono, even case disassembly might be complicated with the extra start/reset buttons/springs. Maybe I'll start on a simpler junker to practice.

The hands are kinda goofy on the 8050, but the dial really is lovely and it looks like it might be perfect under the crystal. Fingers crossed. I'll pick up a watch press and start tinkering. Thanks!
 

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Hi,
I bought recently, a Seiko 6139-6102 with a scratched crystal and decided to try ultra-fine wet and dry and to my amazement produced an acceptable finish; very good by 20:20 vision, but with obvious scratches when viewing with Loop.

Start with P1200 and just circle glass over paper on a hard flat surface and repeat over the entire sheet and use up at least 4 whole sheets. Then repeat with P2000 grit and you'll be amazed!
No need to rush, take your time and have faith!
Regards
 

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If its Hardlex it'll be near impossible to grind/polish.
I have a glassblower friend who refinished my glasses and even he (he's very good at it) couldn't make an impact on Hardlex:(

Replace it.

It comes off from the front; get a pocket knife and you'll see a small cut out where the bezel meets the case. Knife blade in there and lever the bezel off.
Its the only thing holding the glass on.
 

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Discussion Starter · #10 · (Edited)
UPDATE: so, I tried to pop the crystal out... and shattered it. Now I have the case empty but can not get the bezel off no matter what I try. It has a small notch at the 12 o'clock position that I think is for a jeweler's knife but I can't get it to budge and I already did a little bit of damage trying. Any ideas on how to get the crystal bezel off if it's really good and stuck? Photos below:



 

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UPDATE: so, I tried to pop the crystal out... and shattered it. Now I have the case empty but can not get the bezel off no matter what I try. It has a small notch at the 12 o'clock position that I think is for a jeweler's knife but I can't get it to budge and I already did a little bit of damage trying. Any ideas on how to get the crystal bezel off if it's really good and stuck? Photos below:



If you look at the Casing guide I posted for this watch it shows that the bezel must be removed before removing the crystal.

If the notch on the bezel is really small, file down a small screwdriver to fit the slot. Just gently work at it. It will eventually start to lift. As it does gently work around the bezel with the screwdriver.
 

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Ok, so I guess you've figured out that you really should have removed the bezel BEFORE trying to remove the crystal?
What you need is a case knife to gently lever it off via that notch.
You might be best to walk into any small watchmaker's store and ask them to do it. They'll have it off in a moment and probably won't charge you.
 

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Discussion Starter · #13 ·
OK it took forever but it eventually just popped off all at once after hours of fiddling left and right of the divot. I learned a lot, and hopefully a lot of the grinding can get buffed out. In the mean time, the dial was *PERFECT* and it looks incredible with a new old stock crystal. Thanks so much for your help, it looks amazing.

 

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Love it .... what a difference.

Any of the tool marks you left behind should polish out without much difficulty. None of them looked that bad. It's how you learn.
 
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