[samgher]

Hello:

I am a watch collector that started with Seiko classics such 6309's, 6105's and 6217. I have skills for restoring the watches and I would like to share my experience with crystal polishing.

I polished Omegas and Breitling mineral crystals, Citizen crystals and others. This week I polished the Hardlex crystal of my H558 Arnie (the original part was discontinued).

I have used a Dremel with a buffing tool (felt pad) and some compounds such as diamond paste, cerium oxide and others.

The process is very slow and requires a lot of patience.

I do not recommend to use sand paper to remove the deep scratches, even the finer grid. It only worked with a Citizen watch but with the others the crystal turned worst.

For the Hardlex, I have used cerium oxide paste and polished the surface with the Dremel buffing pad. You must ad small quantities of water for lubrication and prevent crystal overheating. As I said, it requires a lot of patience and an hour or more of your time to achieve very good results.

If you can find a replacement crystal, proceed and do not waste your time. If it is not available or you want to maintain the original parts of your watch, use the technique I described.

 

[jdm.watches]

Yes it takes time. However using grit 400 or 600 paper to remove deep scratches is not a problem, the finer abrasives will make do rest.

 

[LongBike]

I found out using a dremel at first only heats the crystal up. Then it blur's it then it has a awful time to reset back to getting it clear again.
It is the heat that does all that. Cold sand is the best for Hardlex.
I use water as I Sand / Buff Hardlex and it keeps it cool too even with a Dremel and gets better results.

I just use by hand a little and hold it flat on thePaper and do it slowly and it turns out better at finish. For bad Crystals I cut it down a little
but like it to be originals for my own.
I also use this for finish but it costs around $40.00 dollars USD, for about half a Quart Bottle. This is used to finish fine scratch's on cars like
Corvettes , Mercedes, and after it is painted with expensive paints.
It cost around $110.00 for a Gallon + for this stuff. My friend always gives me this now when needed because he is a ....Custom Car , Bike Painter and use's it a lot.
This is it and great for watch cases also. Can be used with a Dremel / Buffer / Hand Rubbed / Buffed for fine results.

 

[amebamind]

I have some experience with polishing hardlex
This was my first try on 7002 replacement hardlex glass
I put sandpaper sheet on hard and even surface, and grinden
only by hand in circular motion with some water no Dremel bussines

I used wet sand paper grid 800, 2500 and 5000

first look before damage on glass between 10 and 11



First go with grid 800



again grid 800



than grid 2500



now grid 5000



Than i took cape cod and rubbed for 3-4 minutes



And this is final product



All together took me 45 minutes and 4 dollars.

 

[jdm.watches]

After various experiments I've found that what works best is diamond paste of various grits, applied with a 1cm thick hard felt wheel. Job done in 20 minutes compared to hours with wet paper that no matter how fine always leave strange marks like pitting.

 

[amebamind]

Yes I agree, the wheel is the best. But still it is possible to get good result
with this method. I do not get any pitting. Maybe it would be a good idea to
finish with cerium oxide on leather.

 

[amebamind]

Look at this one, ok it is not hardlex, it is ordinary mineral glass
Took me almost hour with cafe, but you can do it in 20 minutes or less.

before





Grid 800



grid 2500





Grid 5000





final







So it is possible to get good results without any special tools.
Its clear, no abrasions, no "clouds", no pitting.
If you have time, outside is rainy, why not?

 

[DaveA]

Could I ask what grades of diamond paste you use. Up till now I have always used wet emery paper but it takes soooo long. Always get nice result but I have better things to do with my life. Willing to give anything a go to speed it up.

 

[jdm.watches]

I mainly use 10 and 2.5 from aliexpress. If many or deep scratches start with a 5cm roundel of 600 grit wet paper on a rotary tool.

 

[rain10]

Any thoughts on the stuff that you use to clean headlights? I've been thinking about cleaning Hardlex but put off by a long process of buffing, and not knowing if it will actually improve

 

[rob3rto]

Any thoughts on the stuff that you use to clean headlights? I've been thinking about cleaning Hardlex but put off by a long process of buffing, and not knowing if it will actually improve

Most headlights are soft plastic so stuff might not work on glass.

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[IMeasure]

People have no idea how hard hardlex is. Here is something I posted on reddit....

I have tried to take them out and it is almost impossible without a lot of serious effort. For starters hardlex is much harder than glass, not quite as hard as saphire, but close. On the mohs hardness scale, mineral watch glass is 5, hardlex is 8, saphire is 9 and diamond is 10. Regular polywatch is for acrylic, so is useless on hardlex, although they have released a new diamond paste product for mineral glass. But I think I will be difficult to get anywhere with it on hardlex. I have used specialist 3M glass polishing pads with some success, but it's difficult, messy and not worth the effort.
Cheers
Dan

 

[uncleluck]

People have no idea how hard hardlex is. Here is something I posted on reddit....

I have tried to take them out and it is almost impossible without a lot of serious effort. For starters hardlex is much harder than glass, not quite as hard as saphire, but close. On the mohs hardness scale, mineral watch glass is 5, hardlex is 8, saphire is 9 and diamond is 10. Regular polywatch is for acrylic, so is useless on hardlex, although they have released a new diamond paste product for mineral glass. But I think I will be difficult to get anywhere with it on hardlex. I have used specialist 3M glass polishing pads with some success, but it's difficult, messy and not worth the effort.
Cheers
Dan

I did wonder myself whether some of the above have actually been mineral on glass.

I have taken an electric DA sander and 240 grit sandpaper to a hardlex and it hardly touched it! In fact I went down to 120 and tried so hard and long I overheated the crystal and it cracked in half!

The thing that always makes me laugh though is how easily damaged they get from people wearing them! When you can give one that much abuse you wonder how some get them completely scratched to the point the dial is hardly visible through it.

 

[rob3rto]

Was the "sandpaper" the silicon carbide stuff or just plain ole sandpaper?

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[meanoldmanning]

Was the "sandpaper" the silicon carbide stuff or just plain ole sandpaper?

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I was wondering the same thing. I figure it is definitely possible to polish our Hardlex with the right abrasive, considering diamonds are faceted on an abrasive disk.


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[rob3rto]

I was wondering the same thing. I figure it is definitely possible to polish our Hardlex with the right abrasive, considering diamonds are faceted on an abrasive disk.


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Well, glass is 6 on the mohs scale and that is easily polished. I've seen videos where they use silicon carbide loose grit and water to smoother edges of a just sawn glass bottle.

Hardlex is between 6 & 7 on the mohs scale.

Soon as I get my replacement crystal for my Lord Matic , the Old badly scratched one is going to be experimented on.

The "difficulty" is not having access to lapidary machines so it will take hours not mere minutes to achieve anything.

Watch this space

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[TheTigerUK]

I have often wondered if it would be worth going to a optician lens manufacturer to see if they could polish old crystals at a decent price, I have a box full of 6309/6105 used crystals.

 

[rob3rto]

I have often wondered if it would be worth going to a optician lens manufacturer to see if they could polish old crystals at a decent price, I have a box full of 6309/6105 used crystals.

Any flat crystals or even faceted ones could be done by any semi precious gem polisher on their lapidary machine.


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[IMeasure]

Well, glass is 6 on the mohs scale and that is easily polished. I've seen videos where they use silicon carbide loose grit and water to smoother edges of a just sawn glass bottle.

Hardlex is between 6 & 7 on the mohs scale.

Soon as I get my replacement crystal for my Lord Matic , the Old badly scratched one is going to be experimented on.

The "difficulty" is not having access to lapidary machines so it will take hours not mere minutes to achieve anything.

Watch this space

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Great.... Now I'm ebaying lapidary machine.

 

[meanoldmanning]

I'm wondering if I could fit some lap disks to my wet tile saw...


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