1971 Hamilton Dateline A-684 | Restoration

Made from 1971 through 1973, the Dateline A-684 is part of Hamilton's Dateline family of automatic date watches, running on the caliber 694A. The case is 10k Rolled Gold Plate with a stainless steel back, round in shape, and the watch carries a deep golden brown dial. 

As received, the movement was not secure in the case. When the watch was moved, the movement would move and 'clunk' around in the case. My suspicion was that the crystal wasn't installed correctly so wasn't holding the dial and the movement into the case. In addition to the unsecured movement, the owner also reported that the power reserve was very low. With a good cleaning, the power reserve should come back up to the ~48 hours I'd expect for this movement. Hopefully it's just a dirty power train that's the cause and not a fouled mainspring.

The loose movement also probably caused the two-piece stem to seperate. Fortunately the owner didn't lose the crown and male half of the stem and sent it along with the watch.

With the bezel removed, it's possible to see how the crystal is fitted to the case, rather than the bezel.

Yup. There's the reason the movement is clunking around in the case. The crystal wasn't seated all the way into the case, allowing the dial and movement to bounce around.

The stainless steel case back is in good shape, if a little dirty. The green verdigris should clean right up.

The watchmaker's side of the movement has the weighted rotor that powers the automatic works as the wearer moves.

The entire automatic works is removed from the movement.

With the dial removed, the date wheel and the rest of the dial side of the movement is visible. The female half of the split stem is also visible and is in good shape. This is further confirmation that the unsecured movement likely caused the crown to come out, rather than a damaged stem.

Back on the watchmaker's side of the movement, with the bridges, removed, the power train is visible.

And with a stripped movement, the complex mainplate is fully exposed.

This is one of several styles of shock absorbtion use on the balance. The two fingers of the gold-colored spring are manipulated out of their setting...

...and the jewel setting is removed for cleaning.

The same process is repeated on the lower jewel setting of the balance wheel.

The shock absorber is closed without the jewel setting to prevent damage in the ultrasonic cleaning machine.

This caliber uses a third shock absorber on the mainplate. This design is a little finicky to open as is very easy to ping across the shop if not careful.

The jewel setting stays in place, but the cap jewel is removed. This cap jewel is very small and it's much safer to remove with some Rodico.

This give you an idea of scale of the cap jewel.

The automatic works is fully disassembled prior to cleaning as well.

The components of the automatic works.

After fully disassembling the watch, all the parts are cleaned in a heated ultrasonic cleaning machine with solvent and rinses specifically made for watch cleaning.

Uh oh. There is a hairline crack in the mainspring barrel. I only noticed this AFTER I lubricated and installed the mainspring.

The crack was so small that it was all but invisible until the pressure from the mainspring pushed the two sides apart. I'm not sure if this had a huge effect on draining the power reserve, but I'll swap out a barrel from a donor movement.

A clean and shiny mainplate ready to be stuffed with equally clean and shiny parts.

The top balance jewel setting and cap jewel cleaned and ready for lubrication.

The jewels are small.

Much brighter power train now.

The upper balance jewels installed.

Ready to get the dial side reassembled now.

This is the female half of the split stem with grease prior to being reinstalled.

The motion works, keyless works, and date works installed on the dial side.

With the date wheel installed, the reassembly of the movement is almost complete.

The cleaned autoworks plate...

...is reassembled (less the weighted rotor).

The dial is in excellent shape and just need a light cleaning of some dust and schmutz.

But the lume needs a refresh.

I start with cleaned hands, using a balance tack to hold them.

Then using luminescent powder mixed with lacquer, the backside of the hands are painted with the lume.

The hands are then left to dry overnight.

As is the dial with the newly applied dots.

I had the correct acrylic crystal to install to hold the dial and movement in place.

The stainless caseback cleaned up very nicely.

As did the bezel.

A fully cleaned, serviced, and lubricated movement, ready for the automatic works to be installed before going back into the watch.

With the correct crystal and a solid mainspring barrel, this watch is back in fighting shape. The movement is now secure and it's getting ~48 hours of power reserve.

And back on its bracelet and in non-harsh bench lighting, this watch is showing off how it should look.