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Old 18 November 2008, 12:49 AM   #21
CanuckRolex
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Join Date: Feb 2008
Location: Canada
Posts: 282
Quote:
Originally Posted by sbakar View Post
I'm afraid you may be wrong on this. The Mohs scale is relative...so, yes, the toothbrush bristles will be affected more by the metal than the metal will be by the bristles. HOWEVER...your eye can resolve fine scratches that are mere microns deep on a highly polished surface. Using the tootbrush may well cause fine scratches, especially on softer materials such as gold. It doesn't take much to cause multiple micron-level scratches that are visible to the naked eye.

Here's another example: should ordinary glass be able to scratch sapphire? On the Mohs scale, glass is around 5.5 while sapphire is around 9. By your example, sapphire should not be scratched. However, using a glass point WILL scratch sapphire, as a local Omega dealer will attest after challenging me to rub the crystal on the edge of his glass case. Using only light pressure, I made a slight scratch in his Seamaster's sapphire. Not huge, but it was noticeable. Very high point stress concentrations can be created by pressing through a glass point. This WILL scratch sapphire! Granted, the glass probably came out much worse in this, but the point is that the sapphire DID scratch.

Something else to think about: if diamond is the hardest substance known to humankind, how are we able to cut diamond? By using diamond, of course! Both pieces of diamond have hardness of 10 Moh and will thus wear each other equally. Again, the point is that the Mohs scale is relative. It cannot be said that something will NEVER scratch something else...only how MUCH will it scratch!

Back to cleaning gold: use a mild soap (NO DETERGENT!!! This causes seals to shrink - why risk that??) and warm water and you will preserve the high polish!

SNB
Sorry, but you are wrong here. As I am a practicing geologist, having a good knowledge of the moh's scale of hardness is key for mineral identification.

There is in no way a possibility that a soft plastic toothbrush bristle will scratch a gold or any metal surface. Now somthing that gets dislodged during the cleaning (a grain of sand) may get lodged in the bristles and therefore cause the scratches but even then only if you use excessive force, but saying the bristles scratch is nothing less than pure ignorant nonsense and the spreading of uninformed baseless opinion.

If that was the case, some of our synthetic sweaters that are essentially made from a thin form of threaded plastic should scratch the heck out of our watches in no time which again, is nonsense.

Using a soft tothbrush is perfectly safe, using a mild detergent is safe and using water and detergent and a soft toothbrush used very lightly is perfectly safe. You are 100 times as likely to scrath a watch dry buffing it with a polishing cloth than even using water, soap and a TB.

Anyone waving the red flag saying that this is unsafe for a watch with the durability and materials used in a Rolex is being overly neurotic and making up stories to back up pure ignorance and the lack of basic knowledge of the fundementals of metals.
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