Scratch test Applied to Fine_dd AR Treatment

[Francisco]

The dealer Fine_dd from RWI had to send me a crystal to be installed to an AP. So I asked him to send me another one to carry on a scratch resistant test. The results are shown in this thread.

This was my idea and I did not receive any “gift” from Fine_dd.

This is the crystal I received, for a Timewalker. As picture shows, it is broken (top right)

What I am going to do is to repeat a test I published two years ago in a Spanish forum (fororelojero.com) where I compared Chieftang and Taupada (Spanish dealer) ARs.

For that comparison a developed a procedure for measuting AR scrtach resistance. That procedure is employed in this thread.

There are two tests. The first one consists of using the feet of a 7750 dial to try scratching the AR treatment. To make a fair comparison, I employed a 100 grams weight on the dial, to produce the same pressure on the glass.

Folow a picture of one of the feet. A torture test...

The second test consists of employing one Jaxa tool to try scratching the dial. Again. 100 grams weigh is on the Jaxa tool, to apply always the same pressure on different crystals.

APPLICATION TO FINE_DD AR TREATMENT.

FIRST TEST.

Results:

It is difficult to show the micro scratches that were produced by the feet dial. Some pictures follow:

A picture taken using a watchmaker’s loupe:

SECOND TEST:

Results:

After the two tests there are many micro scratches, but they are difficult to spot. Some pictures placing the crystal on the dial.

As comparison, follows a picture I took when the test was applied to Chieftang´s AR treatment, two years ago:

In my opinion, Fine_dd AR treatment is quite resistant to scratching.

Best wishes,

Francisco

[FxrAndy]

Glad you posted this, I have FineDD Ar on my Ingy

[Mickey Padge]

It's nice AR, shame it has a yellow/gold hue

[wheaton26]

i recently had an outer layer removed on my cheif ar'd dssd because of scratches. i wonder if there could have been a flaw in the process this time? the reason i say that is because this is the first time i've noticed any scratches on my handful of cheif ar'd crystals. it was a no brainer to have it removed, first because of the (i'll be it minimal) scratches, but secondly because the double ar actually made the dssd look too good! lol. here's a shot of it with double ar ...