Time Force Quartz Chronograph Miyota OS 10
The Time Force chronograph looks like a
new watch after the crystal cleaning
I had bought the watch ca. 1996 and took the first pictures with the black background ca. 6 years later, in late 2002. Already then I had a feeling that the pictures were not really crip. Now today on April 13th 2007 on the last day of the Thai year, I decided to remove the movement and have a look at the crystal. It was completely fogged. I am not sure what the cause of this fogging is, the movement and the inside of the case were very clean. The Miyota (Citizen) OS 10 chronograph caliber was a lot cleaner then e.g. the same movement found in a Timex Quartz chronograph. No finger prints here. I assume it must have been evaporating battery acid (the battery was not leaking when removed) that caused the crystal to be so severely fogged.
Crystal Cleaning Hints
I am sure different people have different setups, but here is how I do it:
Step 1 - Washing: Use a drop of liquid soap and then carefully rub the inside of the crystal with my index. If the crystal is really dirty around the edges of the crystal, then finger will not reach that area. I have in the past used Q-tips with mixed success. The Q-tips tend to leave fibers in the crystal. So a very good rinsing is necessary if those tabs are used.
Step 2 - Rinsing: I use very hot water to rinse it. I also make sure that I have a very good grip of the case and then I try to shake off all excess water with some strong and fast flicks of the wrist
Step 3 - Drying: I then immediately blow off the remaining one or two water droplets (it is almost impossible to flick off all the excess water the inside of the crystal) with a strong hairdryer. Every tiny water droplet dried in step 3 will leave a very fine line on the crystal (visible with a loupe). If I have a black dial I will return to Step 2 and try to shake more water off. It is really a bit of an iteration and if you have a black dialed watch, you will have to make sure that you will not leave any washing residues on the inside of the crystal. On a black dial, you will see everything that is left on the inside of the crystal
Step 4 - Final Drying: For chronographs with pushers I will leave the watch open to dry for at least 3 or 4 hours. I will make sure that the movement is covered so no dust from the air can settle inside the watch case. Of course the cover should not be entirely air tight, otherwise the drying would be slowed.