Wristwatch restoration, servicing and repair

Posts Tagged ‘Seiko’

Seiko 5246-6000 (King Seiko Special Chronometer)…

At the top of the King Seiko food chain and with enough dial text to rival a modern Rolex, Seiko made it obvious that they were ticking all the boxes with this 5246-6000 Special Chronometer.

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As many enthusiasts will know, Seiko’s vintage watches were produced by two wholly owned subsidiaries; Daini Seikosha Co. and Suwa Seikosha Co. During the 1960’s and early 70’s the two companies were competing to produce Seiko’s flagship models and although both companies produced watches for all segments of the market, the competition was most evident at the ‘prestige’ end of the market where technological development and accuracy were key factors.

In December 1960 the Suwa factory released the first Grand Seiko model, realising their long held ambition to produce a chronometer rated timepiece that exceeded the recognised standards of the Official Swiss Chronometer Testing Institute, the Contrôle Officiel Suisse des Chronomètres (COSC).

In response the Daini factory released the first King Seiko model in 1963, but without a chronometer rating it was deemed inferior to the Suwa Grand Seiko.

What it did do however was spark a rivalry between the two companies which would see the development of some outstanding high-beat manual and automatic calibres which were undoubtedly the pinnacle of their output prior to the quartz revolution.

For a more in-depth overview of the Grand and King Seiko models, check out this excellent two part series written by Evan Yeung for the online watch magazine Monochrome.

The subject of this post is arguably the best watch that the Daini factory produced, but before getting into what’s inside, let’s have a closer look at the case. Turning the watch over you immediately know this is an unusual model as it is completely smooth; no caseback or medallion, just a simple KS logo, model number and opening instructions.

Between the lower lugs is a screw to allow for fine regulation but more on that later…

To open the watch the bezel has to be levered off and the crystal and gasket removed. The mineral crystal is mounted in a stainless steel ring which slots into the gasket and the bezel compresses the two to form a waterproof seal.

When removed, a pin or small screwdriver is then used to press down the lever opposite the 4 marker on the dial and the stem and crown can be pulled out.

A casing spring holds the movement securely in the case which has to be rotated before the watch can be from the case.

Inside is the Seiko cal. 5246A, a chronometer rated 25 jewel automatic movement with a beat rate of 28,800 bph. The calibre can also be hand wound and has quickset functions for both the day and date via the crown.

The architecture is unique to the 52xx family, it shares no parts with other lines. The automatic winding mechanism is typical of the higher end Daini calibres using a roller system rather than the magic lever used on lower quality calibres and there are also diafix installations on the escape and third wheel pivots to prevent oil contamination and promote a more stable rate.

Like all other 5 series calibres, under the dial is a raft of parts making up the calendar mechanism and keyless works. Over-engineered? Possibly.

One last thing to cover is the micro-adjuster mechanism which I alluded to earlier. On the outer edge of the movement is a regulating lever and a screw with an eccentric centre section used to provide fine regulation without having to remove the watch from the case.

The screw between the lugs is removed from the case and a small screwdriver can then be used to rotate the regulating screw, sliding the connected lever either left or right to increase or decrease the rate of the watch. A very useful feature.

Having worked on the majority of Seiko’s vintage calibres I can say that this one is certainly on a par with any of the Grand Seiko calibres and this watch would be a worthy addition to any vintage Seiko collection. The hard part may be finding one as they rarely come up for sale these days.

The movement needed no more than a new mainspring and a routine service this time, so with the case cleaned and the watch rebuilt it was soon back in full working order.

Rich.


Seiko 5740-8000 (Lord Marvel 36000)…

This Seiko Lord Marvel 36000 is the first red dialled watch to feature on the blog and if I think about it now I can’t recall working on more than two or three watches with red dials. I don’t know why they aren’t more popular as I think this watch looks great!

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The Lord Marvel 36000 is quite small by todays standards (35mm) but if you can live with that then there’s a lot to like here. The case lines are sharp and the overall design is crisp with the simple hour batons, dauphine hands and an unfussy dial script.

However, under the hood is where the real action is as inside is Seiko’s 23 jewel, manually wound, cal. 5740C.

As any Seiko enthusiast will know, the 4xxx and 5xxx series calibres are some of the best calibres that Seiko produced and can be found in the majority of the vintage Grand, King and Lord Matic models, watches well worth seeking out.

The cal. 5740C however is quite significant as it marked Seiko’s entry into the high-beat arena and is said to have been the “proving ground” for the cal. 4420 – the high-beat calibre used in subsequent chronometer rated, Grand and King Seiko models.

In the late 1960’s and early 1970’s in an attempt to increase the accuracy of mechanical movements a small number of manufacturers, 12 to be precise, produced calibres with a beat rate of 36,000 beats per hour (10 beats per second), which became known as “high-beat” (or “hi-beat”) calibres.

Although many manufacturers had already started producing calibres with either 19,800 or 21,600 bph, the industry standard beat rate at the time was still 18,000 bph for watch calibres, so when high-beat calibres doubled the beat rate they were seen by many as the pinnacle of mechanical watchmaking used in mass production. Sadly however the quartz revolution curbed any further development in that area.

Rather than get side-tracked into the technical merits of high-beat calibres, I’ll point any interested readers to this post about the excellent Longines Ultra-Chron which I wrote a few years ago. I’ve written about several other high beat watches on blog in the past too including the Zenith El Primero A385, Favre-Leuba Sea Raider 36000 and the Zodiac Astrographic SST to name a few.

Getting back to the Lord Marvel 36000, it actually started life with more ‘low tech’ beginnings. Although the first Lord Marvel models were released in 1958, the first one with a cal. 5740 appeared in 1964 with the “low beat” version of the calibre inside, the cal. 5740A, which ran at 18,000 bph.

A revised version of the calibre, the 5740B, was introduced in 1966 increasing the beat rate to 19,800, and the final version of the calibre, the 5740C, was released in 1967 and featured exclusively in the 5740-8000 model seen here.

This third and last generation of the Lord Marvel 36000 was produced from 1967-1978 in both stainless steel and gold plated cases and with a range of dial colours. Later versions were also produced with linen patterned dials and arabic dial markers.

If you try and track down a Lord Marvel 36000 it’s worth noting that the earliest models had the seahorse embossed caseback found on some early vintage Seikos.

Finding one in good condition may be tricky however as these embossed casebacks wore away quickly when worn, so many are now either severely faded or polished smooth.

As the watch in this post was already in great condition, it needed no more than a routine movement service this time and a case clean to bring it back up to scratch so here it is all finished up. Perhaps I’m just smitten, but what’s not to like here? 😉

Rich.

** Many thanks to Peter Owen for letting me feature his watch on the blog. **


Seiko 6105-8110…

There’s always room for another Seiko diver on the blog, even when it looks like this…

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Although I’ve written about this model before on the blog, as you’ve probably already guessed, this watch needed a little more work than usual to get it back up and running.

Time hadn’t been kind to this watch and neither had the water that had found its way inside. As you can see from the picture above, the moisture had caused some serious deterioration to the lume and also the hour frames and hands. Opening the watch too revealed something of a grim picture.

The automatic winding mechanism had broken off, probably due to the ball bearings rusting solid, and although the winding rotor and upper half of the mechanism were present, it was well beyond repair and would need to be replaced. In addition to being scored by the winding rotor, the balance cock too was incorrect for this calibre as it had the orange painted markings usually found on a 6106 or 6119 calibre, so that too would need to be replaced.

The case was still in reasonable condition although it had been polished by a previous owner and so had the crystal which is notoriously difficult to get right. In most cases, the crystal surface is left with scored lines or is slightly opaque which was the case here, so a replacement was ordered. The bezel insert although marked and missing its lume pip was original to the watch and deserved to stay.

Out of the case the true extent of the water damage to the dial and hands was clear. The lume was totally shot throughout and the dial surface had ‘bleached out’ due to the moisture sitting on it for what must have been at least couple of decades.

The ideal solution would have been to source a replacement dial but being one of the early models with the ‘water 150m proof’ text that would be no easy task. Watches from later in the production run were marked ‘water 150m resist’ due to a change in the US law regarding the water resistance markings for watches. In 1968 it was deemed that all watches sold in the US should be marked ‘water resistant’ rather than ‘water proof’.

Seiko responded quickly to this change and made the necessary corrections for all watches destined for the US in 1969 but they took their time with watches bound for other markets, most of the changes being made during 1970 and 1971.

It’s for this reason that you’ll often see early Seiko divers being referred to as ‘Proof/Proof’, meaning that both the caseback and dial are marked water proof rather than water resistant… and being less in number the collectability (and price!) goes up accordingly.

With no option for a replacement dial, the first job was to remove all the old lume from the dial markers and hands followed by as much cleaning as was possible. As I’ve written about before on the blog, the chrome plating on the markers and hands get tarnished and can’t be restored and while the dial marker frames can be repainted silver, it’s often better just to leave them as they are, this is a vintage watch after all.

With a cream lume applied across the board things were much improved but the bleached out dial remained a problem and would have spoiled the overall look of the watch, so it was decided to oil the dial to restore the colour.

This involves putting an very thin layer of oil across the dial surface so that the bleaching effect is removed. It’s very important to do this carefully as you don’t want to apply excessive oil or it may pool or worse, seep off the dial edge over time. This restoration technique will remain something of a last resort for me, but the results are surprisingly good when correctly applied. Here’s a before and after…

With all the cosmetic work taken care of, the movement was cleaned, serviced and the necessary parts replaced. The case was then cleaned and a new set of gaskets and crystal installed and the watch could be rebuilt. Although it’s not perfect, it’s always good to give a second chance to a watch that could easily have become a parts donor.

Rich.

** Many thanks to Dieter Deschacht for letting me feature his watch on the blog. **


Seiko 6105-8119…

It’s been almost three years since I’ve written about a Seiko on the blog, so let’s have a look at this vintage 6105 diver.

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Replacing the 62MAS, Seiko’s first ever diver, the 6105 was produced from 1968 until 1977 and has become something of a Seiko legend. Having seen a rise in popularity over the last few years, values have steadily increased and all original examples in good condition are now highly prized by Seiko enthusiasts.

The watch was produced in two flavours, the cushion cased 6105-8110/8119 seen here, and also a slimmer cased model, the 6105-8000/8009.

You may see the cushion cased model referred to as the ‘Captain Willard’, so named because Martin Sheen wore the same model in the 1979 film Apocalypse Now.

Unfortunately time hadn’t been kind to the subject of this post and it arrived in poor cosmetic condition. Still in the possession of the original owner who logged hundreds of hours of diving whilst wearing the watch, it was finally replaced in the late 1980’s and has been resting in a drawer since then.

Although the case was in decent shape, the crystal was heavily scratched and as is common to many 6105’s, the lume had deteriorated and the resulting ‘rot’ had eaten away the plating on the hands and frames of the hour markers. You’ll notice too that the SEIKO logo is also heavily tarnished.

With the caseback removed I was pleased to see that the movement was still in good condition with no sign of rust or heavy wear, just a few patches of light tarnish on the winding rotor. The movement in this watch is the cal. 6105A, a 17 jewel automatic which runs at 21,600 bph.

The movement required no more than a routine service, so the majority of the work on this watch was cosmetic.

As can be seen in the dial shot above, the tarnish on the hands and dial markers was extensive, so much so that the chrome plating on the hands had been completely eaten away. Consequently, the owner opted to replace them with a set of 6105 aftermarket hands on this occasion.

The hour markers had suffered too but not to the same extent, so with the old lume carefully removed and a little work done to clean up the tarnish, the new hands, dial markers and bezel pip could all be re-lumed to match. The last job on the dial was to replace the tarnished logo.

The case was then stripped down, cleaned and rebuilt with new gaskets for the crystal, bezel and caseback, but the crown gasket proved to be problematic.

The crown gasket on the 6105 is a known issue as the original crowns were never designed to be serviceable and Seiko never supplied replacement gaskets for them (the whole crown would have been replaced as part of a service). When the crown is made, the gasket is inserted first, a thick metal washer is then pressed over the gasket and the edge of the crown is then crimped/folded over to seal the gasket and washer inside.

The only way to fit a new gasket is to prise out the washer, replace the gasket and try and re-insert the washer – I’ve never attempted the manoeuvre myself, opting to either stick with the original crown, or fit an aftermarket replacement. Here’s a picture of a crown from the internet that has had the ‘operation’ and while it worked, the result isn’t pretty.

Genuine NOS (New Old Stock) crowns can still be found for the 6105 and one was included with this watch, but as the gasket inside is already 30+ years old it is known for them to have hardened in storage, and unfortunately that was the case here.

In the picture below the crown on the left is the original crown in which the old gasket is barely visible after decades of being stretched around the case tube. In the NOS crown on the right, the gasket is clearly visible and, with some silicon lube and moderate pressure, it should slide over the case tube making a tight seal. However, on this occasion the gasket was as hard as rock, rendering the crown useless.

Thankfully the seller of the NOS crown had some more in stock and the gasket in the replacement crown was still soft, so the watch could finally be rebuilt and fitted with a new Seiko strap to finish the job.

Rich.

** Many thanks to Paul Stevenson for letting me feature his watch on the blog and also to Paul Briggs for his sterling work as the middle man. 😉 **


Seiko 6217-8001 (62MAS)…

It’s been a while since I’ve written about a Seiko on the blog, but here’s one of their iconic vintage divers, a “62MAS”.

(Click pictures to enlarge)\

I’ve written about a good few Seiko divers in the past, but this one is historically significant to the brand as it was their first model made specifically for scuba divers.

First released in 1965, the 62MAS was a significant change to the majority of Seiko’s output. It was the first diver to feature an external rotating bezel, and a water resistance of 150 meters. Prior to the 62MAS, the only watch with similar leanings was the Seiko Sportsmatic SilverWave, with an internal rotating bezel and a water resistance of 30 meters.

Although the watch arrived in good cosmetic condition, it had already been on quite a restoration journey. As you can see in the picture below, when the owner bought the watch it wasn’t in good shape at all, missing its external bezel, and having an inscription on the case side.

Having sourced all the missing parts, the owner sent the watch to two other craftsmen to have the dial and hands relumed, and the case refinished before it landed on my bench. My job was to make sure everything was mechanically sound.

Opening the caseback revealed a relatively clean and tidy Seiko Cal. 6217A, though it did have underlying problems. There was a distinct click in the keyless works when setting the time, and the date quickset was very hit and miss, both common problems to Seiko 62xx calibres when wear starts to set in.

This watch has a quickset date, which means that when the crown is pulled out to the first position, it is then possible to cycle through the dates until the right date is showing in the aperture. In watches with significant wear, the mechanism can skip or in extreme cases, the quickset doesn’t work at all.

Looking closely at the date corrector on the left in the picture above, you can see that there is wear on the underside of the teeth. Wear eats away at the teeth until they no longer have sufficient contact to push the date ring forward. Instead, the corrector tooth just skips over the top of the date ring tooth, increasing the wear on both parts. When this starts to happen, the only option is to replace the part with one in better condition, often acquired from a donor movement as new parts are no longer available.

It’s a similar story for the clutch wheel, pictured above right. When viewed with a microscope, you can see that the teeth are severely worn and one of them had chipped off at the end which was causing the clicking in the mechanism when setting the time. Again, the only option is a replacement part.

With the parts replaced and the rest of the movement serviced, things went smoothly from there on. Here’s the watch re-assembled and ready for action once again.

Like several other Seiko watches from this period, the caseback detail has often worn smooth after 40+ years of wear. It was great to see that wasn’t the case with this watch, the dolphin is still crisp and all the print legible.

For more information about the features and history of the 62MAS, check out this excellent collector’s/buying guide.

Rich.

** Many thanks to Duncan Hewitt for letting me feature his watch on the blog. **


Seiko 4005-7000 (27J Bell-Matic)…

I’ve written quite a few posts about Bell-Matics and their calibres, but it’s been well over a year since one appeared on the blog. This one however is somewhat rare, and in some respects is the missing chapter of the story.

(Click pictures to enlarge)

What makes this Bell-Matic stand out from the crowd is that it has a date only calibre, the cal. 4005A, rather than the day/date cal. 4006A found in the majority of Bell-Matics.

The date only models were produced in the early days of the production cycle, and only for a couple of years before being phased out.  Only two models were available, the subject of this post (also available with a blue dial) and this one, available with either a black or white dial.

The cal. 4005A was only available in a 27 jewel version and like all Bell-Matic calibres, the jewel count is clearly displayed on the winding rotor, and the calibre number on the winding bridge.

The main difference between this calibre and the 4006A is of course the calendar mechanism. With the dial removed, comparing the two calibres you can see that the advancing wheel and day jumper found in the 4006A are missing from the calendar plate on the 4005A.

In terms of other differences, the unlocking wheel has no raised boss for the day disc, and the date ring is not as deeply recessed as no additional space is needed to accommodate the day wheel.

Other than that the calibres are identical from a technical perspective, but there are subtle differences in the case designs for the two model lines. The date only models use a different crystal for example.

Although running on arrival, this Bell-Matic had ‘lost it’s voice’. The alarm wouldn’t wind up any more, which all pointed to either a problem with the crown wheel or a broken alarm mainspring.

Sure enough, the problem turned out to be broken alarm mainspring, so with that replaced and the rest of the movement serviced, it was back up and running again.

Rich.

** Many thanks to Neil Lever for letting me feature his watch on the blog. **


Seiko 6138-0030…

Here is another one of Seiko’s popular 6138 chronographs from the 1970’s, and one of my favourites…

(Click pictures to enlarge)

The owner of this watch bought it new in the 1970’s and wore it regularly, until condensation started appearing on the inside of the crystal, a sure sign that the gaskets needed to be replaced. A local watch repair shop agreed to service the movement and fix the leaking problem, but couldn’t source the correct gaskets, so rather than risk any further damage the watch remained unworn.

When assessing the watch on arrival I noticed a grinding noise from the automatic winding mechanism which would need further investigation. With the caseback removed, everything looked to be in order…

… but when I removed the winding rotor, it was clear that something was wrong as the rest of the winding mechanism simply fell apart. The bearing housing of winding bridge was broken, the ball bearings were scattered all over the movement, and the transmission wheel had been snapped in two (although curiously there was only half of it inside the watch?).

Apart from the winding problem, the rest of the movement was in good condition, so with the broken parts replaced and the movement serviced, it was time to turn my attention to the cosmetic issues.

As you can see in the first picture, the crystal had picked up its fair share of scratches and the luminous filling on the hands had darkened over the years, both of which would need to be replaced. A full set of gaskets would also be needed to cure the ‘fogging up’ problem.

After installing the new parts, reluming the hands, and giving the case and bracelet a thorough cleaning, here is the result. The watch still has the original ‘fishbone’ bracelet, which is always nice to see.

Rich.

** Many thanks to Mircea Radulescu for letting me feature his watch on the blog **


Seiko 6139-6009…

I recently bought a number of these models in various states of disrepair, the most interesting of the bunch being this one, a 6139-6009 from 1970…

(Click pictures to enlarge)

Known as the “Pepsi Chrono” because of the blue and red bezel insert, this particular watch is one of the earliest models which has a number of subtle differences that were phased out in later versions. When looking at the case you will notice a small section has been cut out to allow easier access to the crown, the dial has ‘Water70MResist’ written on it, and the centre second hand is the thin, two piece version only seen on early 6139 models.

While the blue dialled version is popular, there is also a gold dialled version which is even more popular. It is also claimed to be the first automatic chronograph worn in space as Col. William Pogue wore one on the Skylab 4 missions in 1973. (More information can be found here).

Although the 6139 arrived in non-running condition and missing it’s crown and stem, it had a lot of things in its favour. The dial and hands were in very good condition, still with clean original lume and the inner bezel had no fade at all.

A missing stem and crown is a very common problem with these watches and if the operation of the rotating inner bezel is to be maintained, exactly the right parts need to be sourced. I wrote about how inner bezels work in a previous post, click here if you missed it.

The movement just needed a service to bring it back to life, so with a new stem, crown, inner gear and spring all located, all that was left to do was fit a new crystal to finish the job…

(Notice also that the bracelet is the same width all the way from the watch head to the clasp. On later models, it flared where it joined the case. All subtle details, but important if you are interested in originality).

Finally, here is an advert for this watch claiming it as the “All Man Man’s Watch”. I’m not sure such cheesy advertising would make the billboards today, but it’s a great line…

Rich.