Polish mineral glass

Posts
542
Likes
1,806
Hi folks,

I don't know if question was raised in the past, but is there a good way to polish scratched mineral glass ?

Did anyone try this before ? https://www.polywatch.de/en/glass-polish

I am about to buy that diving watch from the 70s but the glass is ruined....

thanks for your input
 
Posts
334
Likes
739
I did polish an old SKX mineral crystal with some diamond paste as an experiment but never used the exact same product you provided in the link. The one I used was for industrial glass polishing if I remember correctly. I was able to remove the fine scratches with no problems.
It depends on how deep the scratches are and if there are any chips. Be aware that polishing it too harshly could lead to a weak point in the crystal(provided there wasn't one, to begin with) that will cause the crystal to crack during vacuum testing(if you choose to do so)
Also, the crystal will have to come out and be reinserted. That is another risk since it could crack during reinstalling.
I'm not familiar with these Certinas but I'm guessing crystals are hard to source if they can be sourced at all.
Based on the picture I wouldn't touch it. High risk, low reward plus that scratch that spans from 3 to 5 o clock is large and deep enough, in my opinion, to cause trouble.
I hope this helps.
 
Posts
453
Likes
679
Hi folks,

I don't know if question was raised in the past, but is there a good way to polish scratched mineral glass ?

Did anyone try this before ? https://www.polywatch.de/en/glass-polish

I am about to buy that diving watch from the 70s but the glass is ruined....

thanks for your input

I tried it, the result was zero. The scratches were probably too deep for the product.
 
Posts
26
Likes
135
I’ve tried the polywatch glass polish too (talking about the one from the OP’s link, which is different from the regular polywatch), on the mineral crystal of a Zenith. No luck at all... Either the scratches were too deep or I wasn’t patient enough.
 
Posts
29,671
Likes
76,828
Polywatch is for acrylic crystals

No, there are two types, one for acrylic, and one for mineral glass...
 
Posts
849
Likes
1,749
No, there are two types, one for acrylic, and one for mineral glass...
He’s right you know! I love this forum for many reasons. Learning valuable new things is one of them (I admit this was new to me).
 
Posts
4,339
Likes
10,272
I've watched several videos to polish mineral glass. I have a couple kooky shaped crystals on some old dive watches. Crystals can no longer be sourced. It's on my "to do" list. Set aside some time 🙁. If you have just basic tools, patience is needed.
 
Posts
4,339
Likes
10,272
That video looks too good to be true. Just bought some to try it out.
 
Posts
1,443
Likes
3,810
That video looks too good to be true. Just bought some to try it out.

I haven’t had great success with diamond polish from other brands. Can you please post your review or results?
 
Posts
453
Likes
679
I've watched several videos to polish mineral glass. I have a couple kooky shaped crystals on some old dive watches. Crystals can no longer be sourced. It's on my "to do" list. Set aside some time 🙁. If you have just basic tools, patience is needed.

The same for me, i don´t have a chance to get a new glass for my Zenith XL-Tronic. The glass polish didn´t work so definetly no chance to make it look better 😉

 
Posts
411
Likes
1,411
That polywatch for mineral glas is joke. Dont buy it.

I tried more times but there was almost zero difference.
 
Posts
542
Likes
1,806
That polywatch for mineral glas is joke. Dont buy it.

I tried more times but there was almost zero difference.


Thanks for your input guys !!!
 
Posts
542
Likes
1,806
I did polish an old SKX mineral crystal with some diamond paste as an experiment but never used the exact same product you provided in the link. The one I used was for industrial glass polishing if I remember correctly. I was able to remove the fine scratches with no problems.
It depends on how deep the scratches are and if there are any chips. Be aware that polishing it too harshly could lead to a weak point in the crystal(provided there wasn't one, to begin with) that will cause the crystal to crack during vacuum testing(if you choose to do so)
Also, the crystal will have to come out and be reinserted. That is another risk since it could crack during reinstalling.
I'm not familiar with these Certinas but I'm guessing crystals are hard to source if they can be sourced at all.
Based on the picture I wouldn't touch it. High risk, low reward plus that scratch that spans from 3 to 5 o clock is large and deep enough, in my opinion, to cause trouble.
I hope this helps.

thanks a lot. I am suprised they fit a mineral glass in 1973-1974 on this Certina... an acrylic would have been easier for me.... 😀
 
Posts
743
Likes
2,541
thanks a lot. I am suprised they fit a mineral glass in 1973-1974 on this Certina... an acrylic would have been easier for me.... 😀

I've had one good result. First I sanded by hand with a series of progressively finer sand papers starting at 400 and going down to 3000. I sanded for about 2 hours hours while I watched a movie. Then I used a Dremel tool with a felt pad and cerium oxide slurry for the final polish. It looks great now. The sanding makes the crystal red hot so remove the movement from the case

https://www.ebay.com/itm/392320942485

 
This website may earn commission from Ebay sales.
Posts
542
Likes
1,806
there is a better photo of the glass.... I reckon it is heavily scratched.... the idea is not to get a flawless glass, but rather make it a little cleaner
 
Posts
792
Likes
918
Hard to tell for sure but it looks flat. Why don't you just replace it with a modern sapphire crystal?

I know that in the car restoration business, they sell diamond pads to remove scratches from windows. The vendor stated that if you can feel a scratch with your fingernail, it's too deep to buff out.