Newbie with 7A38-7270

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doing_time
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Newbie with 7A38-7270

Post by doing_time »

Hi folks
Long time lurker and have been after one a while now. In a late night fit of "want that one" I threw in a lowish offer and surprisingly won :?
Was then worried it might not work despite the vague description saying it did. Often a seller isn't aware of all the potential failures...
While it was making its way I said I'd try to be an optimist and ordered a sapphire crystal and gaskets.

I was happily surprised when it arrived as everything was as described with crisp buttons and full functionality.

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Nice! No leaky battery or corrosion and thankfully free of fingerprints. Case back was finger tight tho :roll:

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Gasket was nipped.

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Immaculate beautiful dial. Puts Seiko of today to shame imo with their pressed indices and somewhat garish designs.
I was tempted to pull and re-lume the hr and min hand as despite it not appearing degraded its performance in terms of lume is pants, almost nill in fact.
After thinking about I decided I need to chill, it's nearly 39 years old and besides, I'm not going to go at the indices so there would be an obvious mismatch there. Leave the dial and hands original.

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While I was faffing trying to get a nice even start with placing the crystal I had the bracelet fizzing out a gross ooze of the previous owners ample dna :o

He included a single spare link so that made a total of 22 links. I put ten links off 6 o'clock side and twelve off the 12 o'clock side if you get me. Unfortunately I also had to add a 16mm clasp extender as I've a thick wrist, but the main thing is the watch head and clasp were nicely placed.

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Despite my best efforts the crystal was very slightly crooked by the time I was half way installed. I like to do small incremental presses and rotate the watch head 90 degrees to combat this and have a great record using this method but I resorted to using a much smaller die to locally press the high point slowly to flush. Once corrected I used the 29mm die and brought her home flat as a pancake.

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Excuse the terminator propping it up but here's the fruits of my fifteen minutes of flapping. I'll press it one last press again tomo for final seating. This crystal is 0.05mm thinner than stock I believe. I specd a small chamfer on top and a micro one on the bottom to aid seating it.

Now began the torturous dust eradication palaver. I''m full blown rainman re this craic using a bright torch underneath to identify microscopic dust particles and various methods of ridding the crystal of them. Cousins do a nice Bergeon rip off cleaning pen that I use with some lint free cloths straight from the washing machine and of course, mister squeezie blowie. Dial gets the same treatment with them sticky stick dohickeys.
I aligned the chapter ring and cased the movement, new lubed seal and gave it the back and forth as it just seating (to not nip it) and tightened her home.

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It's a beauty imo. Delighted to finally have one, even if it's not luming!
I asked for lots of clear AR coats on the underside and tbh the only way I can improve it in these stakes is if I got him to coat both sides for that spooky invisible crystal effect, but the coating is prone to scratching on the top side so that'll do pig as he says.

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Seiko7A38
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Re: Newbie with 7A38-7270

Post by Seiko7A38 »

doing_time wrote: Fri Apr 18, 2025 9:08 pmHe included a single spare link so that made a total of 22 links. I put ten links off 6 o'clock side and twelve off the 12 o'clock side if you get me. Unfortunately I also had to add a 16mm clasp extender as I've a thick wrist,...
I checked a couple of mine, which happened to be lying around (daily beaters) and both of them had 22 links (10 on one side, 12 on the other), so I don't think your bracelet was particularly short of adjustment links - you're just a big lad. :P

PS - That's a hefty-looking crystal press you got there Colum. Whose make is it ?

doing_time
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Re: Newbie with 7A38-7270

Post by doing_time »

Seiko7A38 wrote: Sat Apr 19, 2025 7:31 amPS - That's a hefty-looking crystal press you got there Colum. Whose make is it ?
It's pretty affordable for what it is and a game changer for me over the usual lever press one.
https://a.aliexpress.com/_EJY8KrS
I've checked both faces with a gauge block, it's aligned/square. First time I used it I was almost angry with myself for not having bought one like it sooner.

OK so I'm maxed out in links then it seems, I've skinny ankles and thick wrists, maybe I was made from leftover parts :lol: I don't mind the clasp extender as it's no longer than the folding part of the clasp, have them on most my watches.

Would you think my lume situation is particularly unusual or do most suffer at this age? Or maybe this how they were? Last night I gave it a blast of light in the dark and there is lume but only for about four minutes and then it's very weak. I have the Bergeon lume kit with white compound that I've used to great effect on other watches but I'm not sure about meddling with this one.

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Seiko7A38
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Re: Newbie with 7A38-7270

Post by Seiko7A38 »

doing_time wrote: Sat Apr 19, 2025 12:09 pmOK so I'm maxed out in links then it seems,...
You may already have the full complement of links (I need to dig out my NOS examples to check), but there's nothing stopping you from adding more adjustment links - if you can find them (and are willing to pay the asking price). :|
doing_time wrote: Sat Apr 19, 2025 12:09 pmWould you think my lume situation is particularly unusual or do most suffer at this age? Or maybe this how they were?
I can't say I've given it much thought - lack of working lume has never really bothered me. What I do dislike is missing or discoloured / manky lume. I don't even remember how well the lume worked on my original 7A38-7270 that I bought in 1988. What I have sometimes noticed is how different coloured vintage Seiko lume works better on other models - for instance the slightly greener lume on my 7A38-7260's. Some of them will glow for a couple of minutes after I come indoors, after taking a wrist shot. Personally I'd leave well alone. The white paint on those hands can be fragile.

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Seiko7A38
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Re: Newbie with 7A38-7270

Post by Seiko7A38 »

It looks like 22 links (including 6 removable adjustment links) is how they shipped from the factory. Rather than get my case of 7A38-727x's out, I dug out this old photo of the first NOS 7A38-7270 SAA093J that I bought back in June 2011:

rsz_7a38-7270-stainless-blackface-minenos-withsaa093jtag-p1040862.jpg
rsz_7a38-7270-stainless-blackface-minenos-withsaa093jtag-p1040862.jpg (244.44 KiB) Viewed 3447 times

Count 'em up .... 10 on one side and 12 on the other. ;)

doing_time
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Re: Newbie with 7A38-7270

Post by doing_time »

Seiko7A38 wrote: Sat Apr 19, 2025 1:10 pm It looks like 22 links (including 6 removable adjustment links) is how they shipped from the factory. Rather than get my case of 7A38-727x's out, I dug out this old photo of the first NOS 7A38-7270 SAA093J that I bought back in June 2011:
"NOS" and "case" has piqued my interest :D How bad have you been bitten by the bug? ;)

So 22 links is full compliment then, cheers for the pic.

If the white paint on the hands is prone to flaking that would be problematic for re-luming as I soak them in isopropyl for about five mins to dissolve the old lume away. I think in this instance I'll leave well enough alone as the lume is not visually degraded.

We were away for the long weekend and I wore the 7A38 7270. Enjoyed it very much and two non-watch-centric friends commented on it, one saying it was cool to see a "dress stop watch" :shock: :D

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Seiko7A38
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Re: Newbie with 7A38-7270

Post by Seiko7A38 »

My '7A38-727x' case is a 24-slot aluminium watch case. It also contains my 7A38-7180 and 7A38-7190's, besides most of my 7A38-727A's, 7A38-727B's, 7A38-7270's and 7A38-7290's (which all use the same basic watch case). It's full. In fact I have 10 stainless 7A38-7270's in total. Two are currently in pieces, awaiting restoration and one is missing a bracelet. Due to space constraints, only 5 of them live in the case, including the two NOS examples.

The saga of my second NOS example of the stainless 7A38-7270 SAA093J, which was an unintentional purchase on my part, can be found on Page 86 of the old archived forum's One and Only WRUW thread.

doing_time
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Re: Newbie with 7A38-7270

Post by doing_time »

Yep that's pretty bad :lol:
How many 7A28/38 have you in total?!

Fair play to you, it's good to have a passion and beats hard drugs and gambling ;)

I have a fair few* 7t32/62 examples which I'm very fond of, one of which I recently found after being lost for ages and I brought it back to life. Was my first self bought proper watch, as they say.
Spurred on from this I did similar to a couple 7t62's I used to own and even bought some nos/display cases for spare parts I amassed to make complete watches from. Much fun and cursing was had, the 32 seems troublesome, especially where the fragile date change over mechanism is concerned.

On that topic can I ask is it a common occurrence to see similar in the 7A38 re date?

* my fair few is not like your fair few

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Seiko7A38
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Re: Newbie with 7A38-7270

Post by Seiko7A38 »

doing_time wrote: Wed Apr 23, 2025 10:16 amOn that topic can I ask is it a common occurrence to see similar in the 7A38 re date?
I've seen a couple of 7A38's with broken date wheels, but more often than not, it's the day change rather than the date that's adversely affected. The plastic changeover wheel is the 'Achilles heel' of the 7A38 movement. You always ideally want to ensure not attempting to advance the day / date anywhere between 10:30 pm and 3:00 am. I normally hack the watch to 12:00 Midday when advancing dates.

doing_time
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Re: Newbie with 7A38-7270

Post by doing_time »

Good intel and advice, appreciate that. Similar craic as the 7T32/7T62 regards the plastic changeover wheel then :roll: I've replaced more of them than I care to remember. Are the changeover wheels still available and do you happen to know if they are common to other other movements?
They are on the 7T32 / 7T62 so hopefully similar here?

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Seiko7A38
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Re: Newbie with 7A38-7270

Post by Seiko7A38 »

I'd forgotten I'd written a thread about the 7A38's day / date changeover wheel, Achilles heel on the old archived forum.
How to set the Day / Date on a Seiko 7A38 - and when NOT to do it

The p/n for the 7A38 day / date driving wheel is 867.725. They were obsolete, no longer available from Seiko.
However they do come up on eBay from time to time, for example: https://www.ebay.com/itm/135241019051

The part is not common to any other movements, AFAIK, except the Seiko 7A34, 7A36 and Jean Lassale Thalassa 7A74.

doing_time
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Re: Newbie with 7A38-7270

Post by doing_time »

I'm going to have to start digging into the archived forum so! Save myself a lot of trawling.
https://www.cousinsuk.com/product/seiko ... ode=867725
I've bought two of the above seeing as I might probably need one in the future if buying another 7A38.
So the date is rarely affected usually just the day, I'm guessing the wheel having two arms does both day and date?

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