Watch Crystal Polishing

[bobm12]

Wow JD, it seems I'm reading minds since I just came from putting the same model in my amazon wish list! Thanks for showing it and clarifying this whole thing! Much appreciated.

 

...ramrod, if the scratches are very deep, you will have to sand too much down and might not be able to either finish it right (not removing the deep scratches completely) and/or making the crystal out of shape...at least that's my interpretation of it, since we are sanding those critters smooth. Still, it would be interesting to see how you fare!

 

Cheers,

 

Bob

[ramrod]

bob - i know what you mean about the crystal getting out of shape. last year i bought another seiko diver and i could tell that it was polished - hard. the surface is all wavy, but there are no scratches. i would think that simple straight line sanding would do the trick. this crystal must have been done mechanically and they weren't consistent with the pressure being placed on the crystal.

[bobm12]

Very true, the way JD illustrated, I see him sanding against a flat surface. Still, if it is too much/deep the scratch, you are risking of "thinning" the crystal....just let's hope for the best! As for me, I'm getting that dremel...experimentation: that's what's all about! :)

[ramrod]

this would be worth the effort  - if i have the ambition. after looking at it, i think i can get below probably all of these scratches. \on another forum, ausimax (max) had a recipe for polishing glass crystals. i can't put a finger on it, but he was effective in getting some crystals polished out.

if your out there, max, chime in.

[jdrichard]

i gotta tell you that is an excellent job. it looks like a new crystal. i just purchased a seiko diver that needs a lot of help with the crystal. i am actually gonna buy a new one, but i'd be interested in trying this method on this crystal. the diver i got has quite a few deep scratches that i think might not polish out.

the deep scratches will polish out if you start with the 240 grip on a drummel. The drum disk.

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[ramrod]

good to know, jdr. thank you.

[ausimax]

Hi ramrod,

 

I did a few on Seiko sports 100's they are not too bad to do as the crystal stands proud of the bezel, so you can work them in the case (easier to hold), I have a 4 sided diamond sharpening block 200/300/400 and 600 grit depending on how bad the crystal is , but i usually start at 400 grit and grind out all the marks I can see, then on to 600 grit then I move to wet & dry paper on a sheet of glass and work through 800/1000/1200/1500 grit and finish with 2000 grit, then i polish with a felt buff on the dremel and Brasso.

 

Takes a bit of time and patience but they come up OK and as these are on vintage watches that are not going to be water proof thinning the glass is no real concern, a different matter with an active diver I would go with a new crystal, but for old Seiko's the new original crystal is worth more than the watch.

 

Max

[jdrichard]

Max, your technique is basically what I did with the exception that I was able to get rid of the deap scratches with a drum sanding bit (240 Grit) on the Dremel. Where the crystal has a dome, I did rock it a bit to not flatten the top. It is an acquired skill I think but is worth it. On the diving side, I don't think taking a bit off the top of the crystal makes a difference I the structural integrity of the crystal, unless you dive to 1000 feet or more. Most dives are between 40 and 80 feet...i am an old NAUI certified diver.

From Canada

[Pbandle]

On March 11, 2016 at 10:51 AM, jdrichard said:

Ok, revised advice. I took the Crystal once again as there were two small hairline scratches that were just bugging me, and tried to remove them using pumice. That made it worse. Then I used my drumel again and tried to buff out the new scratches; that didn't work. Then I got out the 1200 grit and worked a full sheet of rubbing followed by the 2000 grit and a half sheet of rubbing; THAT WORKED! So new technique should be Drumel with 240 grit drum for the first shooting and major scratches followed by a quick drumel buff with number 6 High Gloss, followed by 1200 grit, Two Sheets of hand rubbing and 2000 Grit 1 sheet of hand rubbing (sanding). DO NOT GO IN CIRCLES while rubbing; back and forth is best. Thanks.

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Hi JD,

My scratches seem to be shallow. Do you think this might work with just a 240 grit paper folloowed 1200 and 2000 grit? Or is the drumel absolutely necessary? 

Thanks, Phil

[jdrichard]

Hi JD,

My scratches seem to be shallow. Do you think this might work with just a 240 grit paper folloowed 1200 and 2000 grit? Or is the drumel absolutely necessary? 

Thanks, Phil

Drumel not necessary. Just use 1200 and 2000 if scratches are not deep

[R1C4]

On 07/03/2016 at 11:01 PM, jdrichard said:

Here is the video I put on YouTube with the technique.

https://www.youtube.com/watch?v=2tQ4LHi0r1g

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Thank-you for taking the time to do a video. I feel confident to give it a go now. 

[jdm]

In my experience the only thing that grit 1,200 and 2,000 do to scratches is waste your time, including on a rotary tool. 

Again from experience the best results come with diamond paste on a felt wheel.

[Watchtime]

Nice result, gonna give it a go on my first crystal polishing today.

[clockboy]

I have tried many methods & all work to a degree. However unless it is a small scratch, if available I just change the crystal.  

[skridlov]

I see this is a dormant thread. Hope that it's OK  to revive it. 

I've just ordered a set of inexpensive diamond paste syringes from a Chinese (where else?) supplier - 5 grades - and 100 cheap Dremel buffing wheels - which I've found to be very rapidly consumed.  I have a question about handling the crystals. When polishing UBs I use a large dollop of Blu-tack (indispensable tool!) moulded inside the lens and then stuck to a flat work surface. This prevents firing the lens across the room whilst buffing. 

My query is, when diamond paste polishing of mineral glass, using the above fixing method, what is the risk caused by heat build-up?

Roy