pantina hands

[pitterpatter]

how come some vintage sub dials and hands turn like brownish color and some have a yellowish tint to them? what causes this.

[pitterpatter]

how come on some vintage dials and hands they turn somewhat of brownish tint and some have a yellowish tint? what causes this to happen.

[taylor]

look up 'patina' on wikipedia

[Wolfgang427]

One word. "Moisture", any exposure to it will "age" the dial and hands.

[learnmore60]

I think because back in the day the luminosity on the dial markings and hands was paint derived from tritium (a radio active material) which has a half life of about 12 years. These unlike todays watches didnt need to be placed in light first before glowing in the dark but were permanently on glow since it was using radioactive material for the brightness.

Anyway I think tritium has a tendency to become slightly yellowish colour with age.

[mike]

Originally Posted by wolfgang427

One word. "Moisture", any exposure to it will "age" the dial and hands.

X2.

Tritium only makes up part of the markers we see.

Tritium dials are made up of;

1.Tritium--the catalyst that "excites" the,
2.Phosphors in the dial to glow (tritium does not glow)
3.The bonding agent that holds everything together--about 90% of what you see.