1956 Accumatic

Sometimes Hamilton watches come with a bit of a mystery... especially when come across two of them.  

This post gets to a good example of a mystery model.  Back in 2015 I had the same situation and I called it the 1956 Accumatic.

The Accumatic introduced a new line of automatic models to supplement the K-series that was introduced earlier.  The Accumatic model line really was a continuation of the Illinois automatics that were introduced even earlier - so you could say the Accumatic line came first, depending on what you called the starting point.

The Accumatic was followed initially by the Accumatic II, Accumatic III, etc. all the way up to the Accumatic XI before being continued with numbers like the Accumatic A-501 starting in 1961.  The Accumatic line continued on into the 1970s, long after the K-series ended.

The original Accumatic was produced from 1956 through 1958.  It was distinctive because of the "flying saucer" case but also because of the dial options.  And here is where it gets interesting.

Here's a photo of the Accumatic with the all-numeral dial option shown in the catalog depiction.  If the case looks familiar, it should.  A similar lug shape was used on the design of the 1955 K-503. 

The similarities are definitely there but as you can see in the photo below of a K-503, the bezel isn't an exact match. 

So what is it that makes the Accumatic so different?  Mainly it's the movement inside... the Accumatic line uses ETA movements while the Automatic K series used Kurth Freres movements (primarily).  That means that if you have a mystery watch with an ETA movement, it's going to be an Accumatic of some ilk.

Of course, ETA made different versions of automatic calibers and continues to do so to power today's modern Hamilton watches.  I suppose you could safely argue that the Accumatic is the great great grandpappy of all Hamilton automatics today.

So onto my project watch.  As I said above, it's the exact same setup as my 2015 watch.  It's an Accumatic dial and movement in a case with slightly different lugs.  The Speidel bracelet is a 1970s aftermarket add on and can be safely disposed of, although it does have one of those funny analog calendar scroll do-dads, which is interesting.

The case back is the same setup as the 1958 Sea-Glo I recently did.  It's a pie-pan disc held in place with a screw-on ring.  They can be tricky to remove if they are secured by layer after layer of "old man funk".  This one is engraved with a presentation from 1958... in keeping with the time frame for Accumatics.  If you peruse the catalogs, there are no other options that utilize this case.  Having now found two examples in the wild, I think you can safely say that this is an Accumatic variation.

Tucked inside the case is a Hamilton 672 movement.  This is the same caliber Illinois models used and clearly dates this watch to 1958 or earlier.  Again, by 1958 you only had a small handful of Accumatic models to choose from and this doesn't match the Accumatic II through V.

Black dialed watches are interesting.  The green lume is an obvious add on.  The appropriate color would be white.  The black dots at the numerals are spent radium lume paint.   Part of the challenge with black dials is if you attempt to clean them they usually turn gray - so you have to be really careful with them.

With the dial out of the way, you can see the business end of the movement.  It's a classic ETA design.

Once the automatic framework is removed, you're left with essentially a Hamilton 671 like what was in the Sea Glo.  The difference would be the mainspring and mainspring barrel.  

Everything is cleaned and ready to reassemble.  I relumed the hands with white lume and the dial too.  Before doing the dial, I treated it to a "poor man's refinish" and gave it a light spritz of lacquer after removing the old radium in my watch rinse.

Like the 671, the trick to this movement is to get the train bridge back in place.  It's not as difficult and the later ETA movements with four wheel pivots to align - but it still takes some finesse to get the bridge to drop on place so all the wheels spin freely.

Once the movement is reassembled and wound up a bit, the balance comes back to life and it can go on the timer.

Not too shabby at all.  I can tweak it a smidgeon from here.

The finished watch looks great with a fresh strap and a new crystal.  The new lume looks a little like new shoelaces on old sneakers but it's a load better than what I started with.  Applying lume, especially to dials, is very challenging.  At least it will glow in the dark again.