Anyone scratched their sapphire?

[COLDI]

I know the sapphire is strong as heck but who here has scratched one? I've got a watch I think is scratched and I've rubbed the heck out of the crystal and the mark is still there. Anything else to test it? Rub on it? It's on a giddy crystal if it matters.

Thanks guys.

 

[MoreCowBell]

From what I gather it's pretty damn hard to scratch sapphire crystal. It's even tougher to rub the scratch out....

A scratch (depending upon how deep I guess) could compromise the integrity of the sapphire. Think of a sheet of glass with scoring mark when you cut it...one odd press could cause the entire glass to break apart...

Having said that...there is still hope.

This might offer the solution you seek..http://forums.timezone.com/index.php?t=msg&goto=1932539#msg_1932539



PS.....just make sure you indeed have sapphire glass and not mineral glass as that might require a different approach/solution.

 

[mysterio]

Yep, since diamond is the only thing harder than sapphire, diamond paste would be the way to go about buffing scratches out of sapphire crystal. A page I read had 3 sizes of diamond paste, the link above uses only two.

 

[ALE7575]

Maybe you have get scratched JUST the AR coating ?

ALE

 

[Nikoteen]

I have a Seiko diver that has a scratch on the saphire....i couldn't get it out but i didn't try diamond paste so i would be interested to know if anyone had success.

 

[Nikoteen]

I just ordered some from these chaps..http://stores.ebay.co.uk/THK-Diamond-Tools-3?_trksid=p2047675.l2563

I'll update how it goes either way.

 

[COLDI]

Might try a little diamond paste. Thanks gents

 

[Wiz]

I sratched the sapphire on my gen breitling a while ago. I don't know exactly how it happend but I suspect scuba diving.

I managed to shade it off using diamong paste on a hard buffing wheel, but it took quite some time, and for the tip, it's better to do it perpendicularly to the scratch.

That said, I never managed to competly remove it, it just became invisible to the naked eye.

And +1 on the pastes from THK, best I could find except for the crazy expensive swiss ones.

 

[COLDI]

This is not very deep so I will try it. Thanks gents

 

[mydnytrydr]

I know this sounds crazy, but it has worked for me...Meguire's Deep Clean auto polish...it gets the swirl marks and oxidation out of auto paint and is GREAT for removing scratches off of your watch crystal..

 

[Nikoteen]

An update from me....I have been cleaning my crystal a bit at a time in the evenings, a few minutes here and a few minutes there...Used 3.5 microns a couple of times and 1.0 / 1,5 finishing..

The fine scratches are still there but can only be seen under the loupe,,,,I used my thumb, finger and a nail polish 'buffer' to rub in the diamond paste.

Unfortunately, i could only get a small section of the scratches on a picture of the crystal before. (you can see the excess paste on the edge of the pic)

I tried but really can't get the scratches to show up on camera....not that i'm complaining
I still haven't finished polishing out the scratches and may well get the dremel on it (You may just be able to see the fine scratch across the 12 marker) which i haven't worked on much...the biggest issue was the scratches near the winder.

So, to sum up, this stuff works, you just have to use a bit of good old 'elbow grease'.

 

[KBH]

Seiko uses a proprietary "Hardlex", not sapphire. And, I strongly suspect that a lot of you guys that think you've scratched a sapphire rep crystal have actually scratched a normal mineral crystal. Sapphire is very hard to scratch.

Here's some info:

There are four main types of crystals that concern us here: Sapphire, Seiko Proprietary, Acrylic & glass.

Artificial sapphire (as is used for watch crystals) is grown in a crystal lattice, unlike the flame-formed sapphire, like the kind you find in common graduation rings. The Sapphire crystals used in the overwhelming majority of watch crystals are artificially grown (in a boule. Once formed, the boule is then sliced and the pieces are then cut and polished to the desired shape. This material is very hard an resistant to scratches from common every day use, but it is also (like diamonds) brittle and has a tendency to shatter on impact (provided the impact is just right). Flame formed sapphire while chemically identical, lacks the internal crystalline structure and is much softer and brittle.

Hardlex is a Seiko proprietary type of hardened mineral crystal and comes in at least two different varieties (what goes in Seiko 5's is not the same quality of what goes into ISO divers). Hardlex is closer to 7 in the Moh's scale, but is much more flexible than sapphire. IOW's sapphire is harder but more brittle. Hardlex will scratch easier but resists impact much better. You can read more about Hardlex and the different types of it here:

http://www.larrybiggs.net/scwf/index.php?mod=103&action=0&id=1037842045

Sapphlex is also a Seiko proprietary type of hardened mineral crystal that is laminated (layered on the outer side of the crystal) with sapphire. The idea being to provide the best of both sapphires's superior scratch resistance and Hardlex's superior impact resistance.

The types of plastics used to make acrylic crystals has varied widely throughout the years. From a performance POV there are acrylics out there which perform very well in professional divers (most dive computers today use acrylic crystals). The problems with acrylics are that although they can be made to be very very impact and preasure resistant (at least in higher end ones), they are highly susceptible to scratches from simple bumps that would normally not scratch a simple mineral crystal. Provided the scratches are not too deep, they can generally be easily buffed out with the appropriate tools.

Buffing out scratches on mineral crystals (of any kind - sapphire included) is possible, but difficult and time consuming. even then if you are able to remove the scratch, you run the risk of altering the shape of the crystal in that spot. There are no real guaranties as to the quality of results. Although it is possible, it is usually not worth the time and effort to repolish a mineral crystal. Also, since replacements are generally inexpensive, most people prefer to just replace them.

 

[ALE7575]

Good post KBH
Rep points added
Congrats
ALE

 

[Nikoteen]

KBH...excellent info...and explains a few things....that Seiko crystal is hard...really hard. However, i can only see the scratches on mine under a loupe (imagine an ice rink after skaters have been on there and you get the picture).

Thanks for the info and I'm sure it will come in useful for others that come across this thread.

 

[offshore]

We do a sapphire polishing kit-
http://watchbitz.com.au/shop/index.php?_a=viewProd&productId=39

Below are our instructions for use-

Watch Bitz Sapphire Polishing Kit.
Instructions for use
Sapphire glass is a synthetic material with a very high hardness, (around 9 on Moh’s scale, as below.)
Moh's Hardness Scale
Hardness is measured on the Moh's Scale, identified numerically hardness of by standard minerals, from 1 (softest) to 10 (hardest):
1.Talc 2. Gypsum 3. Calcite 4. Fluorite 5. Apatite 6 .Orthoclase 7. Quartz 8. Topaz9. Corundum 10. Diamond.
A mineral of a given hardness will scratch another mineral of a lower number. With a systematic approach, you can use minerals of known hardness to determine the relative hardness of any other mineral.
To polish a sapphire, we need a product harder than it, so here a diamond polishing paste is used. We have put together this kit of 2 grades of diamond paste, for this job. The 3.5 micron is used initially to remove the deep gouges and scratches, and the 0.5 is used as a final polish.
If you are attempting to polish a crystal which is still in the watch case, we recommend that you tape or mask off the surrounding case and bezel areas, so no diamond paste comes into contact with these areas. It is much easier to polish a crystal that has been removed from the case.
You may need to polish a sapphire crystal for some time, using the 3.5micron (red) polish. (Up to 20-30 minutes to achieve a good result) Always check every few minutes, as to how the polishing is progressing, and once the crystal is free of scratches, apply a final polish using the 0.5 micron (rose) polish.
Polishing can be done, either by hand, using a soft cloth, and polishing with the forefinger or thumb, or can be carried out using a felt pad attached to a Dremel style machine. Note: If machine polishing, check your progress at regular intervals, as you may have removed the scratches very quickly.

Hope that helps!
www.watchbitz.com.au

Offshore

 

[rbj69]

If affordable buy a sapphire crystal for it and be done with it. I'm doing this for some ap watches that are not sapphire. Joe rbj69

Sent from s4 Active, it's waterproof like our watches

 

[ALE7575]

We do a sapphire polishing kit-
http://watchbitz.com.au/shop/index.php?_a=viewProd&productId=39
Hope that helps!
www.watchbitz.com.au
Offshore

Nice and helpful post Offshore

Many thanks

ALE