Citizen Hisonic

August 29, 2020

Here is my most prized Citizen Hisonic. The design of this one is so retro it deserves a high place in my collection. Like my other Hisonic on this website this one also came with extensive battery leak damage and was not running. As I had learnt from the other one disassembly was uneventful now being an easy and straightforward procedure.

My process is to strip all dial side components first before flipping the movement over and disassembling the movement / tuning fork side.

Removing the train wheel bridge reveals the small train of wheels which includes the very delicate 300 tooth 2.4mm diameter index wheel. This has to be handled with extreme care.

I also carefully disengage the pawl and index levers from the index wheel as they too are fragile being so thin.

Once the index was out I inspected and unfortunately I found that it was damaged beyond repair. Clearly some battery leakage got on it and over a decade or two rotted it away.

You can see it here as the black part of the wheel. There is actually a bit of it missing.

I would have to source a new wheel but for now I stripped the rest of the parts off ready for cleaning.

Now for the crystal. There was a big long scratch running across the whole crystal, as its hardened glass crystal there is little to be done easily but I set out to see what I could do using a felt wheel, some grades of diamond paste and scratch gene diamond paste. I came down the grades from coarse to fine. Well 6 microns to 1 micron ! still fine if you ask me. The problem doing it like this is heat. The glass gets very hot from the friction so you have to stop every few minutes to allow to cool. It probably took an hour or so on and off but I did get some decent results. I could still see some of the marks in certain light angles but the improvement was satisfactory.

You may ask why I just did not change it. Well I cant seem to figure out how the bezel comes off. There is no slot for a knife which implies to me that it might have to be pressed out with the glass. I did not want to risk this and break it.

A few weeks later I was able to buy two broken Accutron 218 movements (which are what is installed in these Hisonics) at a very reasonable price due to them being complete non runners and no cases or dials . Perfect for me!

I removed a index wheel, cleaned and then rebuilt this Citizen Hisonic. It fired up with a new 344 battery installed and I phased the index for it to run correctly on the higher voltage. As said in my other post the Accutron 218 was originally designed to run on a 1.35v mercury battery which are no longer made.

So here is the finished watch in all its glory.

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