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The verb ‘to squirrel’ derives most obviously from the foraging habits of that most iconic of tree-dwelling rodents and is synonymous with the concept of hoarding, caching or accumulating something of value for later use.  Squirrels typically display a foraging behaviour in which they select the food type based on a conservation of energy principle in which they try to balance the energy expended in obtaining and consuming the food against its nutritional content. My own foraging habits are guided similarly by a logic operating at the border between my conscious and subconscious.  While I confess to regularly finding my eye caught by some bright new prospect, the follow-through is often motivated either by the need to tie up loose ends or to provide some sort of counterpoint to other unrequited projects. A case in point is illustrated by this latest entry.  Three and a half years ago, my head was turned by a mid-60’s Seiko Business-A 8346-9000, a close cousin to the Seikomatic-R counterpart.  My interest was piqued I think by a combination of the opportunity to tackle once more an 83 series movement and the appeal of the sharp and distinctively modern lines of the case and crystal.

I won the auction and once landed, I located a slot for it within my repository and quickly forgot about it.  Just under a year later, I came upon an eBay auction for a vintage Seiko watch case and crystal from a seller in the USA. The case was an old stock 8346-9000 in more or less as new condition and it appealed of course because I thought I might use it when rebuilding the Business-A example.  I was also interested because the crystal in these watches is the 320W10GN, the same part used in the 6105 dive watches.  Original, unused examples of Seiko OEM crystals of this type can fetch double what I’d paid for the complete case and so I figured it was a bit of a no brainer.  Another 10 months passed by and I happened upon an auction for a gold plate Seikomatic-R 8346-9000, this time fitted with a very dark brown/black dial with gold indices and hands.  The typically poor condition of the case meant that I secured this last piece for little more than pocket change.  Two more years have passed since and here we are, teetering on the edge of summer 2019, the world order crumbling about us, and I think I’m ready to tackle my small pile of acorns.

With the two watches side-by-side, it is clear that in all but colour scheme and branding they are identical.  The gold-plate watch is the older of the two by four months and carries the Seikomatic-R branding.  The younger steel watch is badged as a Business-A model, designed to appeal to the younger businessman market.  The fact that the two watches have the same design sits at odds with the logic of their respective brandings but perhaps the gold plate would more obviously have appealed to the older generation buyer.  Regardless of the reasoning, both watches are striking, handsome and do not really look like a product of the 1960’s.


A Seikomatic-R 8346-9000 from October 1966

I am going to focus first on the gold plate Seikomatic-R because that is the more obvious candidate for a re-case, the plating having worn through to the base metal in many places.  The 27 jewel 8346A movement looks in much better condition than the case.

The 8346A differs from the 8306A in having 3 fewer jewels, a difference that may originally have been driven by marketing logic rather than cost considerations, perhaps to more closely align the 27 jewel Business-A models with the parallel 26 jewel 6206-powered Business models.

The dial is pretty much clear of marks or obvious flaws but the hands are a little scratched.

The case is in very poor condition, with the usual plating wear compounded by serious corrosion around the edge of the lower lip where case meets the steel caseback.  This case is unsalvageable and destined for the cylindrical receptical.

You will notice that the crystal is of exceptionally high profile.  I think this must be an example of the Type I 320W10GN and the reason for its withdrawal from production fairly early in the production lifetime of the 6105-8000 becomes obvious when you take a closer look at the edge of the bevel surrounding the flat top.

The scene is now set to attack the movement.  As I’ve previously documented the workings and design of the 83 series in some detail, I don’t propose to duplicate that again here but will pause at pertinent points to highlight anything notable.  Let’s start with the calendar side, the main obvious difference, compared with the 8305, being the presence of a day wheel.

The dial side of the main plate reveals another difference compared with the 30 jewel 8305: a simple jeweled bearing serving the fourth wheel in place of the Diafix setting in the 8305.

The same is true of the train bridge with one Diafix setting replaced by a simple jeweled bearing.

These two missing Diafix cap jewels account for two out of the three fewer jewels on this movement compared to the 30 jewel 8305/6.

Any temptation to indulge in minor shortcuts, such as leaving the first reverser idler in place, quickly evaporates as we realise that we have to remove this part in order to access the second of the two screws securing the centre wheel bridge to the main plate.

It is also worth observing that on movements of this age that may not have been serviced in decades, you should probably not rely on your ultrasonic bath/watch cleaning machine to remove all of the caked-on mucky neddy that may have accumulated in, on and around the jewels.

An initial manual clean with sharpened peg wood is advisable before moving onto the cleaning machine.

With all of the parts clean and dry, reassembly begins with fitting and oiling of the Diafix cap jewels and the refitting of the mainspring.  I have opted to replace the mainspring with a new part in spite of the original looking pretty healthy.

Having first fitted the winding stem and setting parts, we can set the centre wheel, its bridge and the sweep second friction spring.

The second reduction wheel, barrel, ratchet wheel and the three train wheels next find their way into their respective positions.

And before you know it, the remaining parts on the balance side are assembled and the watch is up and running, with the mainspring wound to full power.

Thus far, this movement has not thrown any tantrums or revealed any obvious operational flaws.  On a full wind, the amplitude is hitting about 270 degrees and the timing trace looks clean and tidy.  Of course, having noted the lack of drama at this point, reassembly of the setting wheel lever and its componentry reveals the first fly in the ointment: one of the teeth on the setting wheel is missing which means that in operation the setting wheel slips and setting the time becomes problematic.

The condition of the clutch wheel also betrays reciprocal wear that will not have been helping the situation.

Neither of these parts are in free supply and so I have to raid my cache of spare 83 series movements to source healthy replacements.

The new parts can now be test driven by refitting the remaining calendar parts and then putting it through its operational paces.

Everything works as it should, day and date wheels clicking over around the midnight point and the quickset date functioning correctly.  The day mechanism on this movement is not quickset but can be shuffled along to the required position fairly quickly by swinging back and forth between just past midnight and about the 9pm position.

I find myself now regularly in the habit of checking the rear of the dial to see if it is date-marked and whether any such marking coordinates with the date indicated by the serial number on the case back.

The 60 stamp indicates a manufacture date of October 1966 which is exactly the same as indicated by the first two digits of the serial number on the original dolphin caseback.

We’ve reached the point at which we contemplate re-casing the movement.  The original SGP case is a write-off and so I assign the old stock steel case as a suitable home for the freshly serviced movement.

Unfortunately, the case did not come with a crown and so I have to source a steel crown from one of the 8306 parts watches that I’ve had languishing for a number of years.  The stem on the parts watch crown is too short for this case and so I’ll need to swap that over.  The crown itself features a properly encapsulated gasket and unsurprisingly it is hardened and no longer fit for purpose.  I resolve to try the gasket extraction routine described elsewhere on this blog.  For those of you new to the process, it involves serial micro-gasket stuffing to the point that the retaining washer cries out in protest and adopts the appearance of a prolapsing sphincter (apologies for that imagery!).

Eventually, the washer can be released, providing access to the gasket.

You should be able to see that this design of crown does not really allow for a clean escape route for the washer with the result that the lip of the crown is somewhat mangled by the experience.  However, we should remember that this is an exercise in restoring water resistance not a beauty contest.  Having cleaned the crown and located a suitable replacement gasket, we can lubricate it and introduce it to the crown.

The injured washer is fitted using a staking tool, shortly followed by the original stem, harvested from the crown from the original case.

One of the features of both watches that I particularly enjoyed was the exaggerated profiles of their first-generation high top tempered mineral glass crystals.  The crystal fitted to the new case is of a much lower profile and I decided to replace it with the only other Type I 320W10GN that I have:  an aftermarket facsimile produced originally by East Tech Manufacturing.  That crystal is currently fitted to my first 6105-8000 but to be honest, I’ve never quite got on with the shrinking effect that it has on the dial of that watch.

And so I resolve to perform a swap.  First remove the lower profile 320W10GN from the new 8346 case, revealing a pair of box fresh crystal gaskets.

Having extracted the high top crystal from the 6105, I clean it and fit to the 8346 case.

That’s more like it!  It’s not especially relevant to the current project, but it is worth just taking a look at how the low profile OEM crystal from the Seikomatic case now looks in the 6105 case.

I am really happy with the result.  It is perhaps a little lower of profile than is my ideal for these watches but I think the effect with this example is spot on.

We are now ready to unite the movement with the case, fit the crown and stem and survey before packaging the whole lot up.

I think it is just worth remarking what a handsome movement this is and what an air of sophistication it offers compared to some of the parallel Seiko calibres of the time whose somewhat more agricultural magic lever autowind systems were fitted as additional modules to base movements original conceived as hand wind.

Gasket lubricated, the case back is screwed into position and we can take a look at the effect from the front.

You will have your own opinions I am sure about whether you think this is a successful transformation but I for one am more than satisfied.  The only loose end now is the choice of strap.  I rather think that this watch needs a bracelet but I have only one contender and that has been bagsied by the other watch.  I choose instead to fit a black crocodile Hirsch.

This concludes part 1 of our two-part project.  Part 2 follows shortly.