1960 Thin-o-matic T-502

There was a time when my least favorite Hamilton models was anything in the Thin-o-matic line.  It wasn't a particularly long time, and it was mainly because I found the microrotor movements to be very challenging to work on.  I ruined quite a few learning the tricks of the trade.  There's a lot tucked into a fairly compact movement, and you have to be very careful during reassembly.

There are at least 57 different Thin-o-matic models, if you include the TM-line.  The list grows to 85 if you included the Dateline models with a calendar complications.  They're actually great models - just a bit more complicated than traditional manual winding movements.

Thin-o-matics actually come in three flavors.  The first is the pink microrotor calibers that were produced by Buren.  Most of the Thin-o-matics fall into this group.  A smaller group of Thin-o-matics featured ETA movements that were similar to the Accumatic line, just a lot thinner.  The third group is the TM line with silver colored microrotors.

One of the earliest Thin-o-matics was the T-502.  It was the third stainless steel Thin-o-matic and followed the 1959 T-500 and T-501.  The T-502 is unique in that it has a grey colored textured dial that looks like linen.

The T-502 was made through 1965 but the last two years is was the T-502B.  Hamilton used the B nomenclature when there was a change in movement that required a different case design, even though the outside of the watch looked the same.  I'm not sure what changed with the T-502B but I suspect perhaps it opens through the crystal while the original has a two-piece case.

My project watch arrived in "as found in a drawer" condition.  It's pretty beat up and it's missing the crown - a classic sign that the watch opens through the crystal.  Could this be the elusive T-502B?

I had to look really hard at the back of the case.  I don't see a pronounced lip, indicating the back snaps on.  However, it doesn't look entirely like a one-piece case either.

I took bracelet off and could make out a little slit between the lugs that I could fit my case knife into.

With a crisp "snap" the case back popped off.  So this is a regular T-502 as far as I can say.  It even has the classic microrotor drag mark inside the case back from the oscillating weight spinning around.

I don't think this movement is installed correctly... it has two case braces but they are on top of a spring ring that surrounds the movement.  I think the braces should go under the ring.

The two braces are removed, as well as the ring.  Then the movement can be lifted out of the case.  You can see the crown is missing because the stem rusted off.

The dial is in decent shape.  It would be impossible to get refinished properly so I will just leave it as is.  I can clean up the hands at least.

Now that the dial and hands are removed, I can start stripping the parts from the movement.

While the parts are in the ultrasonic, I'll turn my attention to the old Speidel bracelet.  The owner asked me to see if I could clean it up, as it has sentimental value to them.  The bracelet is a calendar design with a little scroll that can be moved through a window to show the month desired - in this case, it was August 1971.  The first step is to remove the dirt and DNA that has accumulated over the last 50 years. 

One cleaning session and two rinses later, and the movement is now sparkling clean.  I also replaced the crystal and gasket in the case back.

The movement is almost back together.  The balance is ticking away but I still have to put the balance jewels back in.  This movement had two odd-ball screws from a prior watchmaker.  I replaced those with the correct screws from a donor movement.

The movement is running nicely!  The beat error is just within my personal specs of 3.0ms or less.  It's not an easy adjustment for this movement so I'm glad I can leave it as is.

With the movement sorted out, now I can turn my attention to replacing the stem and installing a new crown.  The stem will need to be trimmed to the correct length to match the placement of the crown on the case stem tube.  It's a little tricky, as if you trim the stem too short, you have to start all over.

Alright, the stem is trimmed, the crown is on, the braces are installed under the spring ring.  Time to close up the case.

The finished watch looks great now - even on the cleaned up Speidel bracelet.  This watch can now spend some time on the wrist and enjoy not be trapped in a drawer somewhere.

1972 Sea Haven III

It's interesting to note that there are almost 50 Sea-somethings in Hamiltons model lineup.  That's about 5% of the men's models but the first Sea-something didn't get introduced until 1957 with the Seabrook.   I don't know what started the trend of naming models with Sea but it continued well into the 1970s.

One of the 1970s models is the 1972 Sea Haven III.  It was produced for two years.  It's unique in that it's one of a small handful of models to feature a blue dial.

The Sea Haven III is unlike it's earlier Sea Haven predecessors.  It's cased in a stainless steel case where the 1964 Sea Haven and 1968 Sea Haven II are cased in 10K yellow rolled gold plate.  The only similarity between the three is they all utilized the same movement.

My project watch was sent to me after the owner said it suffered a hard fall.  Although it still ran, he noted it now had a rattle like something was loose inside the case.  Since it hadn't been serviced recently, he sent it to me to check out.

As received, it doesn't look too bad.  The blue dial is definitely unique.  I think if this was on a blue and white NATO strap it would look pretty cool.  I like the white chapter ring that extends around the inside  perimeter of the crystal.

The case back screws on to the rest of the case.  The model number is 688014-3.  That's interesting, as it gives you a clue to what's inside the case.  The -3 implies a stainless steel case.  If it was -4 it would be yellow gold RGP.  That would be a different model, of course, but the case shape would be similar.

The inside of the case back says Hamilton Watch Co. Swiss.  That's because this watch came from Switzerland, as production in Lancaster ended in 1969.  I see no service marks inside the case back.  I wonder if it's ever been cleaned in 1972.

Inside the case is a Hamilton 61 caliber.  It's hard to see that it also says Hamilton Watch Co and 688.  This is the same movement that was used in the earlier Sea Haven models - although those would say HYL on the balance cock, as that was the import code Hamilton used for their Swiss-made movements.

The good news is there is nothing loose inside the case.  I think the rattling going on was just the assembly held in place by the two case ring braces.  Perhaps they were bent in the fall but there's not a lot of play to them - just a slight amount.  Perhaps it will be fixed when I reassemble it.

At this point everything gets disassembled and thoroughly cleaned.  The 688 is the granddaddy of modern ETA movements.  There have been improvements, of course, and today's beat rate is faster than 18,000 beats per hour, but this movement is otherwise identical to today's manual wind movements.  It doesn't hack though, so that's one major difference, along with beat rate.

Everything goes back together smoothly.  After a few winds to the mainspring, the balance swings back to life.

Not too shabby... the amplitude is a little low but it's not fully wound yet.  The beat rate and error are fine, but I can tweak them with little effort.

I sped it up a smidgeon and reduced the beat error - this is about as good as it gets.

A little Polywatch buffing cleared up the crystal and a new cork strap provides a crisp, but funky, look to this clearly 1970s watch.

1964 Dateline A-579

It's interesting to note that if you research the "Hamilton Pan Europ" you'll likely find the interweb thinks the origin is the 1971 Hamilton Chronograph, or more specifically, the Chronomatic D.

This model utilized the Caliber 11 movement that was also shared with Breitling models.  The Caliber 11 is a micro-rotor powered automatic chronograph developed by Buren, which was owned by Hamilton at the time.  It was such a popular model that new models were introduced in the last 10 years that were inspired by the colorful design.

However, although the Chronomatic D said Pan Europ on the dial, the first use of Pan-Europ was the 1964 Dateline A-579.  So it makes me wonder what the original purpose of the Pan-Europ logo was.  I suspect that it was a series of models, along with the Estoril line, for use outside the US - but that's just a guess.

The Dateline A-579 was introduced in 1964 and produced through 1967.  The model was cased in stainless steel and features a calendar complication at the 6 position.  There are similar models that are not in the catalogs, including a very similar model without the calendar complication - and that's part of my rationale for saying there was a non-US model line.

The Dateline A-579 is a cushion-shaped model, similar in shape to Hamilton's original men's wrist watch from the 1920s.  In this case, the cushion shape comes from a snap-on bezel that attaches to the case and surrounds the round crystal.

The case back shows the model number 64017-3 - it also shows a plethora of scratches from someone trying to get the back cover off.  The cover says Hamilton paneurop and "model depose" - which is a French phrase that translates to "registered design" or "patented design".  The Pegasus logo is interesting - it reminds of an Omega Seamaster rear cover.  There was also a Hamilton Pegasus model - it's one of the Electric models.

Fortunately the rear cover didn't give me too much of a fight.  It opened to reveal the Hamilton 694A movement used in the Dateline Accumatic models.

The movement is held inside the case by a couple of braces that screw into the main plate and attach to the movement ring.

Uh-oh, the brace is missing from the crown-side of the movement.  All I see is a broken screw head and no brace.  Hopefully I'll be able to get the screw out.

With the dial and hands out of the way, you can see the business end of the date complication.  There are actually different calendar wheel options, depending on where the design places the dial opening.  Since this watch has the window at the 6 position, the number is upright at the 6 position.  If the window was at the 3 position, it would be a sidewise 14.  The movement functions the same, regardless of the printing on the wheel.  Once the hands pass 12:00 midnight, the wheel indexes clockwise one position.

The 694A is based on the Hamilton 64 and in this case the main plate is stamped A as well.  I have heard that the A represents "anodized" and that the barrel is anodized on the 694A but not anodized on the 694.  There's also a difference to the shape of the automatic framework.

All the parts are cleaned and accounted for - even the pesky U shaped spring that likes to disappear if you're not super-careful with it.

I was able to back the broken screw out of the main plate - so if I have an extra brace I should be able to secure the movement with two braces and not just one.

It took me a while to get the balance in position and to start running.  The position of the hairspring stud looks out of position to me, and very close to the regulator.  That would introduce a significant beat error and make the watch run very slow.  The timer will tell me for sure.

Yikes!  The watch is ticking but the timer can't pickup a clean rate.

Eventually I decided to use my best guess for where I though the hairspring stud should go and gave the timer another shot.  Now it's running with an excellent beat error but it's still a little slow.

Okay - now we're talking... a tweak here, a tweak there, and I got the timing right in line now.

Notice the change in position of the regulator and hairspring stud now... it's very different from what I started with.  You'd never be able to make these sorts of adjustments without a timer and a little experience. 

Next, I'll install the dial and slowly advance the time until the date wheel indexes.  Now I can install the hands at 12:00.

I happened to have the correct brace and a screw to secure it.  Now the movement is installed and properly held in the case.

One of the challenges with this model (and those similar to it) is the shape of the lugs.  They are very short and require a curved spring bar.  If you use a strap, it has to be unpadded in order to curve to fit the contour of the case.  

I looked online and was able to spot the correct Kreisler bracelet that was original to this model (see the catalog add).  When it comes to bracelets, there's a lot that goes into it - including the shape of the ends to fit the case - in this model, they have to be curved.  There are similar bracelets out there but the ends are straight and won't work.

This was a challenging project but with a proper bracelet and a fresh crystal, it now looks as good as it runs!