Seiko 7A38 - by the numbers

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Forum Home > Parts Info, Tech Tips and Tinkering > 3 W's - a Warning about Warming and Warpage

Seiko7A38
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Posts: 14137

At some point in your collecting activities, you may be unfortunate enough to encounter a Seiko 7Axx or other watch that is suffering from 'old sticky oil' syndrome. Basically this means that the original oils applied to the jewels and moving parts has thickened with age. So instead of acting as a lubricant, it acts as a brake. This usually manifests itself in a watch that either won't run, or regularly stops for no apparent reason; loses a lot of time (particularly between 11:00pm and 2:30am) - or sometimes a recalcitrant sweep second hand.


The only proper solution is to strip and clean the movement, removing all traces of the old dried-up oil, and re-lubricate with fresh oil.

However, there are albeit temporary solutions. One of them is to gently warm the watch. Doing so, reduces the viscosity of the old oil.

When I've done it myself, I've left the watch on a shelf in the airing cupboard for a few days. I've had some limited success with this.

I've read elsewhere (had it recommended to me, by someone who should know better) about leaving the watch on top of a radiator.

If you try this yourself, all I will say is be VERY CAREFUL  about where, and for how long you leave the watch 'warming up'. 


May 4, 2013 at 5:41 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 14137

Earlier this week, I had recourse to go back and read an old thread on the RLT watch forum.

I may have 'walked away' from there myself, but there's still a wealth of information to be found in old topics.

I was looking for a quote of mine in a thread about the 7A28-7120 RAF Gen. 1 (which I quickly found, quite easily) ....

But later on I went back to the beginning of the thread (to read it all the way through) and remembered how it started:


http://www.thewatchforum.co.uk/index.php?showtopic=66398 .... the OP began:


I received a trashed gen 1 7a28 RAF issue. The watch has suffered water ingress and movement is gone, dial is ok, chapter ring is knackered it's not round anymore but square!!

Hand seem ok. I know I could get another 7a28 movement from fleabay to replace, but does a 7a38 fit? And where could I get a chapter ring to fit, or what model has an identical ring?


As I stated in the thread, the chapter ring in a 7A28-7120 is exactly the same part as used in the 7A38-7010, Seiko p/n 84310763:

http://www.thewatchforum.co.uk/index.php?showtopic=66398&view=findpost&p=669759 (the 7A38-701A's is a slightly different colour).

If I remember correctly, DaveS subsequently sourced one (from a beater 7A38-7010) and ended up rebuilding the 7A28-7120 for him.


May 4, 2013 at 5:50 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 14137

We never did get to see a photo of the OP's old dial ring, quote: chapter ring is knackered it's not round anymore but square!!


Keeping in mind what I wrote about the slight difference in colour (black versus dark grey) of the 7A38-7010 and -701A's dial rings ....

I think I may now have some idea what happened to the dial ring of the original RLT poster's 7A28-7120, and how it may have looked.

I was browsing the Italian Orologi & Passioni forum last night, catching up, reading a few recent 7A38 threads I'd missed.

Found this one, posted a week ago: http://orologi.forumfree.it/?t=65757861 - about a rather tired looking 7A38-701A.

 

Ringrazio chi mi darà informazioni su questo Seiko 7A38, in quanto in rete non ho trovato niente circa la seconda parte della ref. 701A.

Mi piacerebbe sapere se ha un certo interesse collezionistico, il significato della sigla [A3] dopo la referenza riportata sul fondello, se è facile o meno reperire un bracciale acciaio adatto, originale e coevo e magari un inserto ghiera in miglior stato.

Grazie a tutti x l'aiuto

P.S. l'orologio funziona perfettamente






Look carefully at the minute ring !

It's no longer circular, but in places between the batons (which will have restricted its shrinkage), it has developed flat 'square' edges.

In his reply, '6309 7040' (a.k.a. Manuel) wrote: Peccato per il rehaut deformato. Translates as: Too bad about the warped inner ring. :(

Plastic, particularly old brittle thin plastic can warp of its own accord, but especially when subjected to heat. You have been warned. ;)


May 4, 2013 at 6:07 AM Flag Quote & Reply

6309 7049
Member
Posts: 34

Seiko7A38 at May 4, 2013 at 6:07 AM

We never did get to see a photo of the OP's old dial ring, quote: chapter ring is knackered it's not round anymore but square!!


Keeping in mind what I wrote about the slight difference in colour (black versus dark grey) of the 7A38-7010 and -701A's dial rings ....

I think I may now have some idea what happened to the dial ring of the original RLT poster's 7A28-7120, and how it may have looked.

I was browsing the Italian Orologi & Passioni forum last night, catching up, reading a few recent 7A38 threads I'd missed.

Found this one, posted a week ago: http://orologi.forumfree.it/?t=65757861 - about a rather tired looking 7A38-701A.

 

Ringrazio chi mi darà informazioni su questo Seiko 7A38, in quanto in rete non ho trovato niente circa la seconda parte della ref. 701A.

Mi piacerebbe sapere se ha un certo interesse collezionistico, il significato della sigla [A3] dopo la referenza riportata sul fondello, se è facile o meno reperire un bracciale acciaio adatto, originale e coevo e magari un inserto ghiera in miglior stato.

Grazie a tutti x l'aiuto

P.S. l'orologio funziona perfettamente






Look carefully at the minute ring !

It's no longer circular, but in places between the batons (which will have restricted its shrinkage), it has developed flat 'square' edges.

In his reply, '6309 7040' (a.k.a. Manuel) wrote: Peccato per il rehaut deformato. Translates as: Too bad about the warped inner ring. :(

Plastic, particularly old brittle thin plastic can warp of its own accord, but especially when subjected to heat. You have been warned. ;)


HI Paul,

I bought a 7A38 701A.

You can see it on the thread you mentioned.

Greetings

Manuel

May 23, 2013 at 2:11 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 14137

A different one, I hope, Manuel. :D Yes - it is. ;)


http://orologi.forumfree.it/?t=65757861#entry534995319


Is that the ex-Strega_68 7A38-701A ? :/ No it's not - I've answered my own question. Yours is s/n 393247, that was s/n 393410. :)

May 23, 2013 at 2:44 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 14137

Here's another example - a 7A38-7029 with a badly warped Tachymeter ring, I spotted while searching on ended listings on eBay.com.


http://www.ebay.com/itm/231166483374

GENTS SEIKO 7A38-7029 S/S SPORTS 100 CHRONO QUARTZ NICE PRICE RUNS BUY IT NOW


February 25, 2014 at 6:32 AM Flag Quote & Reply

donwatch
Member
Posts: 568

Like a dog chasing it's tail--another parts watch :P

February 25, 2014 at 10:01 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 14137

So Is that another one you've snaffled before anybody else got a chance for a second look, Don ? :o

Actually, as the seller stated in their description:  A VERY NICE WATCH TO REFURBISH

With some careful sympathetic re-finishing of the case and bracelet and a new crystal, that might make a half decent watch.

Problem is going to be sourcing a new Tachymeter spacer ring (Seiko p/n 84311023) for it. :/

Cousins UK and Seiko (UK) did have stock remaining, a few years back, but you know how it is. :P


But then again, perhaps that depends whether it needs to be kept warm (and warping) to keep running ! :lol:


February 25, 2014 at 11:14 AM Flag Quote & Reply

donwatch
Member
Posts: 568

I probably can guess where all those spare Tachy rings landed. :lol:

February 25, 2014 at 1:10 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 14137

All long since used in various projects, Don. ;)

I do however remember the unfortunate fate of one of them. The only time I've ever picked up the wrong size crystal press die. 

February 25, 2014 at 1:42 PM Flag Quote & Reply

donwatch
Member
Posts: 568

The 7A38-7029 Sports arrived the other day and I've been messing with it. Here is a mock-up of how it may go back together-I may put a two-tone band on to give some more color. " Franken"


March 1, 2014 at 5:04 PM Flag Quote & Reply

donwatch
Member
Posts: 568

The 7A38-7029  Franken Beater. :roll:


March 3, 2014 at 11:44 PM Flag Quote & Reply

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