Rusty hands and green crystals

[Uncle Myer]

Several old American watches I own have green crystals and very rusty steel hands. Is there any correlation between the green colored crystal and the rust on the hands? I have not seen this level of rust on watches with glass crystals and clear plastic ones. Myer

 

[Uncle Myer]

Several old American watches I own have green crystals and very rusty steel hands. Is there any correlation between the green colored crystal and the rust on the hands? I have not seen this level of rust on watches with glass crystals and clear plastic ones. Myer

 

[Jerry Treiman]

YES. The plastic used in some of the older "unbreakable" crystals gives off corrosive gases as they age (indicated by turning yellow or green). You will almost always see rusting of the hands occurring with these crystals, as well as corrosion of the exposed end of the cannon pinion. Whenever you get a watch with one of these discolored crystals, one of the first things you should do is replace the crystal and have the hands restored or replaced to prevent further damage.

 

[Stephen1529]

I just I would put in my 2 cents worth. I am not a watch expert but I have seen plastics and things made of plastic react to ULTRAVIOLET light. I think the plastic crystals are turning color because of the years of UV exposure. The heat from the sun reacting with the paint on the dial could also have an effect on the crystal too. As for the hands rusting - moisture settling on the hands could be a culprit. The watch is worn in cold / rain / snow / and very hot weather have take it's collective tolls on the watch hands and movement which in most cases is not air tight esp. on the older ones and not able to acclimate as fast as the changing enviorment. Like I said this is my 2 cents worth and it could be worth only 2 cents. --

 

[Wes]

Jerry is right - there is certainly the corrolation between discolored plastic crystals outgassing and seemingly causing the oxidation on the hands.
Certainly remove (ideally replace) the plastic crystal before it does more damage.
Happy collecting!

 

[Jerry Treiman]

The crystal is definitely the culprit. A number of years ago my brother did an experiment, placing some steel parts in a sealed container with some pieces of yellowed watch crystal. Within a short while the steel was showing rust and eventually was completely deteriorated.

 

[Uncle Myer]

Thanks for the informative answers. Myer.