6218, Dress watches, Modified watches, Seiko, Seikomatic, Vintage
Oh dear. What have we here?
Grist to my mill is what. Something most sane folk might reasonably consign to the scrap heap but what I know, and what you should know by now, is that watches that look like this, more often than not, are ripe for revival. The chronic cosmetics are a signpost to the fact that this is a well used watch that has not been footled around with too much during its long life and therefore likely to contain some innards with potential.
This watch continues a recent Seikomatic theme here but this one is a bit of a minor aristocrat, fitted as it is with the 35 jewel 6218 movement, one clear level above the 26 jewel 6206 fitted to the Seikomatic featured a couple of posts back. Let’s not get ahead of ourselves though and instead take a closer look at what we’ve got.
The caseback reports that this is a Seikomatic 6218-8950 dating from July 1966, a model that came in two flavours; this one, with a gold-plated brass case and gold-highlighted dial and hands; and a more sober steel–cased version with the same model number but without the gilt-edged ostentation. A view of the lower lugs provides no more basis for reappraisal than the initial view of the face
but does serve to highlight the very nice softly-domed crystal. The crystal fitted to the steel-cased version of the same watch has sharp edges, which suggests that this one might be a non-standard replacement but I’ve seen a few examples of the gold-plated version with the same style crystal and so perhaps this was a distinguishing design choice in the original watches. What is clear at this point is that the case is a write-off, the underside showing considerable wear and none of the original sharp edges remaining (anywhere). However, I have a solution to that particular problem, as long as the insides look a little prettier than the exterior. Fortunately, that turns out to be the case:
Given the massive wear to the exterior, the movement looks surprisingly fresh, with very little evidence of rotor wear to the edges of the bridges. A nice surprise is that this relatively late example is fitted with the third ‘C’ iteration of the 35 jewel 6218 movement, boasting a fine regulation adjuster on the balance cock in place of the teardrop adjuster we met during the 62MAS hot-rod project.
I had somehow expected an immaculate dial to lie beneath that crazed acrylic crystal but, although it was in decent condition overall, the markers and hands were quite badly tarnished, potentially letting the side down rather and undermining what I hoped to achieve.
Short of removing all of the markers and replating them, my only option appeared to be to polish the tarnishing away without removing too much of the gold plate. In the event, this proved very tricky. On some markers the tarnishing had penetrated through both the gold plate and the nickel plate beneath, whilst on others the tarnishing was relatively light, affecting only the surface of the gold plating. The end result is not quite what I had hoped, comprising a mix of semi-silvered markers showing remnants of gilt on exposed nickel plate beneath and others where I had had to work all the way through to the brass. Somehow though I am not unhappy with the result. We’ll see how it turned out towards the end of the post.
Extracting the movement requires the two case ring screws to be removed first, followed by the case ring and then the movement which, with the autowinder removed, provides a nice view of the fine adjuster on the balance cock.
In some ways, although the fine adjuster provides a very nice degree of control over the regulation of the movement, it is geared directly to the regulator and so that control is somewhat coarser than provided by the teardrop regulation in the earlier editions of the movement.
Removing the dial and hands provides a view of the calendar side and an opportunity to compare this side of the movement with the closely related 6206A.
The differences appear rather minor: a slightly different design of day and date driving wheel and the presence of two additional jewels on the date dial guard and date jumper guard. Removing the two jeweled guard plates and the date dial reveals an additional seven jewels running around the recess in which the date dial runs.
With the extra two jewels in the guard plates, that brings the added value over the 6206 to +9 jewels, none of which play any significant role in the smooth running of the movement, other perhaps than in aiding a slicker passage for the date and day dials.
As we’ve seen quite a lot of 62xx movements recently, I won’t dwell on what was an uneventful dismantling and cleaning, other to take a quick peak at the usual encrusted barrel arbor hole in the main plate, happily exhibiting not too much wear.
The return leg proceeded reasonably smoothly barring one heart-stopping hiccough when refitting the setting wheel plate:
It doesn’t happen often, but sometimes screws just come apart without any provocation, a bear trap waiting to undo all of the effort expended in getting to the point at which they shear. If they break in the main plate then it can potentially be a show-stopper, particularly in a watch such as this one whose main plate is not interchangeable with the humble and far more common 6206. In this case, lady luck was smiling on me, the screw remnant still turning easily in the threaded hole and easy to work through, dropping out harmlessly on the other side. A replacement screw sourced from a scrap 6206A and we can move along, heart beat settled once more.
As the rebuild continues, it’s worth pausing to take a look at the stop seconds lever (hacking lever) fitted to this movement, and of the same construction as that in the 395 movement used in the 62MAS project:
You can see that it works by acting on the fourth wheel. In the later 6106, 6105B and 6306 calibres, the hacking lever works by coming into contact with the balance wheel directly. You can see the three positions of the lever in the photos below. In the first, the crown is pressed in; in the second pulled one click out to the quickset date position and in the third, pulled two clicks out to the time setting position. In this last, you can see the lever making contact with the fourth wheel:
In completing the calendar side, the only real potential fiddle is in the fitting of the date jumper and date jumper spring. In the date only variants of the 62xx series (such as the 6217 and 395), there is no outer lip to help keep the date ring in position under the gentle pressure of the date corrector spring. In my experience, the jumper and spring can only be persuaded to remain in place by simply willing it to do so through a process of horological transcendental meditation. Happily, with the day-date variants of the caliber, the date ring sits in a groove with lips either side and will generally stay put reasonably happily while you locate and fit the date jumper guard.
In the first photo above, we can see the date jumper positioned (and clearly itching to fling itself across the room) before fitting the guard plate whose dual role is to keep the date jumper in position as well as house the day jumper spring.
As we saw earlier, the calendar side is all but identical to that of the 6206A, but with a slightly different design to the day and date driving wheel. As we can see in the photo below, the location of the day and date fingers at 180 degrees to each other means that the date and day change over more or less in unison, rather than in the staggered fashion of later designs in the 61xx and 63xx series movements.
I quite like the design economy of having the date finger sit in a groove in the upper day driving wheel, thereby causing the latter to perform its function of driving the day disk. You can perhaps see a little better how this all works by looking at the figure below taken from the 6218A service manual:
The manual reports that date driving mechanism works by transferring torque from the hour wheel to the intermediate date wheel to the day & date driving wheel to the date finger and on to the date dial. The day driving mechanism works by transferring torque from the day & date driving wheel to the day finger to the star sitting beneath the day dial disk.
With that all done, all that is left to do is fit the day dial and dial spacer:
ready to receive the dial and hands. I’ll save that particular reveal until the end though as I am still not quite sure to what extent the de-tarnishing of the markers has been an aesthetic success. Let’s turn now to the case.
At about the same time as I bought this particular flawed gem, I happened upon an auction for an unused, old stock 6218-8950 steel case and managed to bag it. Here it is:
As the case had been stored for the better part of 50 years, some of which evidently not in any protective wrapping, it is not entirely immaculate and the crystal in particular has that scuffed look acrylics can get which you know will not easily buff out. So, I removed the crystal, separating it from the dedicated tension ring which is designed to sit neatly around the outer edge of the dial. The tension ring I then fitted into a new 33 mm diameter crystal intended for the 6218-8971. This latter crystal has a softer, more rounded profile more in keeping with the crystal originally fitted to the now discarded gold plated case.
In the event, the replacement crystal was a tad too broad of beam to fit into the aperture and I had to reduce its outer diameter a tad before pressing it snugly into place.
The case came without a crown and so I had to source a new one from Cousins and swap over the stem.
We are ready now to fit the movement to the case. As the case ring is secured to the case using tabs, the movement goes in first, followed by the case ring, crown and stem and case ring tabs, secured using a pair of screws:
The final step is to fit the autowinding mechanism and rotor, seal her up and finally take a look to see whether the new look works or not:
I have to say, I rather think it does.
With a strap fitted we can take a look at the gorgeous dolphin case back, still showing some remnants of the green/blue case back sticker.
A few more and we can wrap this one up.
Lovely piece of work yet again mate, all I need you to do now is a ladies 4205 diver to help me out renovating one that I have for my sister
I wouldn’t hold your breath on the 4205 front. The only small diver on the horizon at the moment is a 2625 and after that, all those slight of wrist in my family are taken care of!
Peter White said:
Damn it man i implore you to do one haha, only kidding, guess im on my own then, cant wait for your next project to arrive in my inbox though, thanks again for sharing your knowledge with us.
martin….i’m curious. how do you know exactly that a certain movement will fit into a certain case? for instance, i have an old 60’s seiko sportsman with a 66a movement. the case is knackered and i’d love to put it into a modern case as you did here. is it simply trial and error, or is there a table somewhere with all of the measurements of each movement? still, you have differing thicknesses of the movements to deal with.
Every case is designed to fit a movement of a particular diameter and with a particular stem height (the distance between the top of the dial and the stem hole in the movement). The 6218-8950 described in this post originally came in either a gold-plated brass or stainless steel case. The cases are identical apart of the material used in their construction. So in this example, I managed to find an unused old stock 6218-8950 case in steel, knowing that everything would fit.
In general though, if you want to find a case to fit a particular movement, the absolute minimum requirement is that the movement diameter is appropriate and the stem height is correct. For movements with calendars, it matters too where the crown is located – a movemement sourced from a case with a crown at 3 o’clock may need calendar disks replaced if you plan to transplant into a case with the crown at 4 o’clock (or vice verse).
In your case, if you want a case to accommodate a 66a, then any case originally designed with the 66a in mind will work, including the automatic and calendar variations (6601, 6602 etc). The reverse may not work though because the case backs on manual wind watches are generally not deep enough to accommodate the rotor.
Hope that helps
that helps greatly. i never knew that stem height would have been a critical dimension.
thank you very much for the explanation.
John Ammerman said:
Why didn’t you remove the hands and marker and replace them with silver ones from a donor watch so they would match the steel case?
I ask because I’m thinking about doing the same operation eith a gold-plated Sea Lion and a NOS SS Sea Lion case. Should I do it? Would it be a restoration, or a Frankinwatch?
In my case, I worked with what I had available and that did not include a spare dial and handset from a steel cased watch. I rather like the overall look of what I’ve ended up with and so would not be inclined to tinker further even with a spare dial and handset to hand.
As to your dilemma, the issue of swapping the cases is either a pragmatic one (the existing plated case is in poor condition) or you just fancy something different. I see no harm in using steel cases to house the innards from gilt watches because they are so obviously what they appear.
Always such a pleasure to read your write ups, thank you for sharing!
Philipp Ganglberger said:
Dear Martin, hope my message finds you well, we have not hear3 from you for some time. I would like to ask how did you get off the tarnish from the markers? I have the same problem with one of mine! tried brushing which made it a tiny bit better but its still tarnished. Any info is very appreciated.
Hi Philipp, as I recall, I used kitchen roll wrapped around a pair of tweezers and moistened with Cape Cod polishing liquid. Residue then cleaned off with lighter fluid.
I appear to be on the finishing straight of a slightly troublesome project with a new post to follow so watch this space.
Hi Martin, I hope you don’t mind me asking. But what is the correct crystal number for the 6218-8950 watch and do you have a link to where I would be able to find this information. Thank you in advance
Hi Sten, the crystal part number is 330T04AN. I recently bought a couple from a seller on eBay. A search there should turn up any sellers who still have stock. Good luck!