Job Number 190043

We see a lot of pocketwatches with discolored plastic crystals. They can appear tinted blue or green but yellow is the most common. Sometimes it appears that the color is the dial, but it's not.

The crystals are not supposed to be this way, they were originally clear. Over decades these early types of plastic decayed and changed. While doing so, they gave off a corrosive gas that very commonly, as is the case on this Hamilton, severely damages the hands and often the dial too. In the worst case, the corrosion will extend to internal parts inside the movement through the center of the dial.

It's temping to think that plastic crystals are always "cheap" replacements. But this is not necessarily so. Plastic crystals were considered a technological improvement over glass as they were said to be "unbreakable".

Some people prefer to leave these crystals on as original. This may be fine. Many believe that the degassing stopped long ago. On the other hand, some say that the old plastic crystals should always be replaced to avoid the risk of further damage. I don't know. This plastic crystal was replaced with glass.

Broken mainspring...

 The train...

The Hamilton pallet fork and pallet bridge...

Hamilton hairspring stud clamps, which are pretty small, have two small screws, one for each side of the stud. It always takes a little holding of breath to get these placed with the balance bouncing around, but there are a few tricks that make it easier.

Follow all my watch repair projects in detail here.

And the album for this Hamilton project is here.