On certain jobs I need to use an alcohol lamp in order to heat a part to be used with shellac.  His is done when replacing a roller jewel or a pallet stone.  I did a blog post a while back and showed how to replace a roller jewel.  Today we will talk about repairing a pallet stone.

How to Replace a Roller Jewel

The first problem that I have run into is I recently ran out of the methyl alcohol that I use in my alcohol lamp.  I purchased this bottle of alcohol 11 years ago from our pharmacist, he is now out of business.  This small bottle has lasted me all this time,  Goes to show how often I use the alcohol lamp.   I made a tip to our new local pharmacy and asked about buying more alcohol.  The pharmacist told me that they no longer are allowed to sell this product.  She had no idea where I could buy more of it locally.  It is highly toxic and unfit for drinking.   She made a good suggestion and told me to check the liquor store.   So my journey found me at the state store asking the clerk what type of alcohol would burn in my lamp.  She did a quick google search and found that 151  Rum is flammable.

It is named for its alcohol proof level of 151, that is, 75.5% alcohol by volume. This is much higher than typical rum at 35%–40%. It is the highest alcohol level that the store is allowed to sell

I figured I would take a shot and buy a bottle, if it did not work, then I could have a few rum and cokes after work.  I tried the rum in my alcohol lamp when I got home and it works perfectly.  Lights easily, buns clean, so we are good to go.  I am guessing that this bottle of rum will last the rest of my life, my son Tom will probably still be using it long into the future.  I tried a quick drink of it, and 151 proof liquor is strong stuff, a bit more than I can handle.

 

Now on to the pallet stones.

The relationship between the escape wheel and pallet is the heart of any mechanical watch. Tolerances are tight, everything needs to be just right in order for the watch to run properly and keep accurate time.

Escape wheel on left and the R stone with arrow. The face of the pallet stone must slide across the face of the Escape wheel tooth perfectly. The tolerances are in the 1000 th of an inch. about the width of a piece of paper
R (release stone) properly catches escape wheel tooth
L(Lock) stone must catch the escape wheel tooth, lock must be just right, not too much, not too little.
The problem on older watches is that the shellac that holds the stone in place dries out with age and that will let the stone move or come loose. here is where the repair comes in.

 

Pallet stone on holder ready for some heat
Cleaned stone on holder ready to be heated and shellac added
Alcohol lamp fuled with my 151 rum heats the pallet stone and holder ready for a new dab of shellac

 

Stone with new shellac, nice and tight ready to be reinstalled back into watch