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Monday, April 21, 2014

1927 Ladies' Tonneau - Overhaul

Arguably, Hamilton's first wrist watches were ladies pendant watches that were presented on a rope "strap".  They go back to the early "-teens" of the last century.  But once the 6/0 men's models were introduced in the 1920's, other ladies models were also introduced.

The ladies line-up was similarly spartan - and only a handful of "geometric" models were available, named for their shape.  One of them was the 987 Ladies' Tonneau.  It was produced through 1931.  It was also available earlier than 1927 with a 986A movement - but the 987 model came out in 1927.


The Ladies' Tonneau came presented on a ribbon strap with what was surely a very attractive matching clasp.  I've never seen one though, so I can't say for sure.  Ribbon straps are extremely rare since very few have lasted intact for 80+ years.

You will find this model in green and white gold filled as well as solid gold.  There are also a number of different sterling silver dials that were available, as well as various hand styles.

The cases are always heavily engraved and their large size makes quite a statement on a lady's slender wrist.

I've actually restored quite a few ladies watches but "my better half" doesn't have the same affinity for watches that I do.  So most of the time I use their movements as donors for men's models I'm working on… especially if their cases are worn-through, which is common.

I recently received a Ladies' Tonneau in need of love and since I didn't have one on the blog yet it was a good opportunity to tell you a little about the model.  As received, the watch is in nice shape.  There's no wear-through because this one is solid 14K white gold.  The crystal has yellowed and there's a replacement crown installed that I think is probably stainless steel - it's color and shape aren't quite right so I will replace it.


Like the men's models, this watch comes in a three-piece case.  There's the back, the center (that holds the movement) and the bezel (that holds the crystal).  A metal stub on the center case aligns the back and the bezel with corresponding holes.

Here the bezel has been removed.  The movement comes out the front, once I remove the crown / stem and the two movement case screws.  This style of hands is called "spear".


One the other side, with the back out of the way you can see the two case screws that hold the movement in place.  Technically you could drop a 987A into this case but only the earliest 987A's have holes for case screws.  Otherwise the movement would only be held in the center by the stem.  Of course, a 987A really isn't appropriate for a 1920's watch, since it was introduced in 1937.

You can see by the blurred balance wheel that the watch is running.  It's actually running about 3 minutes fast per day (180+ seconds) and the regulator is set towards "slow" - so I may have to fuss with the timing screws on the balance to "speed it up".


With the movement out of the case, I can remove the hands and the dial.  First things off (after the dial) are the hour wheel and cannon pinion in the center.  I'll also take out the minute and setting wheels.


Next, the movement is flipped over and after making sure the mainspring is fully "let-out" I can disassemble the back.


Watches with 987 movements usually have a "set" mainspring so I'll open the barrel and check it out.  In this shot, when the mainspring is in the barrel you really can't tell what shape the spring is in.


But once the spring is removed, you can see that it doesn't splay out very far - this shows that the spring has "set" and lost most of it's energy.  The watch would run - it just won't run as long as it should… ~ 40 hours.


All the parts, save the balance and pallet fork, go into my baby food jar with cleaner.  Then the baby food jar goes into my ultrasonic.  I'll clean the balance and pallet fork separately.


The cleaning, rinse, and rinse cycle takes about 25 minutes from start to finish so while that's going on I will prep the case for a new crystal, etc.  First I have to remove the remnants of an old metal bracelet.  These can be a real bear to remove and it's not unusual for me to end up jamming a screwdriver into my finger tip.  Needless to say, there's no love lost between me and these metal clasps.


The case is now polished and ready for a new glass crystal.  Sometimes these engraved cases can be highlighted with black enamel.  I usually do that with the men's models but I'll leave this one au naturale - it looks great the way it is.



Glass crystals are held in place with UV glue - so you have to let it cure in either sunlight or under a UV lamp like below.


Now a fresh white alloy mainspring gets installed before the watch is reassembled.


Here's all the parts (except the bezel), ready for lubrication and reassembly.


These old balances have timing screws that allow you to adjust the speed that the balance turns.  If you've noticed a spinning ice skater, when they pull their arms in they go faster and when they put their arms out they slow down.  The same is true for the timing screws on the balance.  If you move them in the watch will run faster and if you pull them out, the watch slows down.  Of course, you need to adjust them correctly or you'll ruin the "poise" of the balance… so it's tricky business.

As you can see below, with the regulator still set towards slow, I was able to slow the watch down from 180+ seconds fast per day to 57 seconds slow per day.  Now I can move the regulator to speed the watch back up.


0 Seconds per day… that's pretty good.  Plus the amplitude is above 300 thanks to my new mainspring and the beat error is very good too.  This watch is running very well.  Now I can put the dial and hands back on and reinstall it in the case.


Well, here it is, all put back together and looking as great as it runs.  This watch looks 100% better with a new glass crystal and a correct crown.  Don't you think?


One of the challenges of cases with fixed lugs is how to put a strap on them.  In this case I fed a single piece strap through the lugs across the case back.  But you can also buy what are called "open straps" that allow you to pass a section through the lugs and either glue it or pin it closed.  This strap will do for now.


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