Toad's Guide - Sea Gull ST19 Keyless Works and Freezing 6-o-clock Subdial

[Toadtorrent]

Hi folks,

My usual preface: I am not a watchmaker...but a hack. There are some things I'm going to do that a watchmaker would shudder at. There is also some dust on the pics presented that would make Pugwash, Zig and others puke. The lighting on the pics is terrible...sharpness is bad...composition terrible...yada yada yada. BUT, I did do this work inspired to make a tutorial to help others out including my bud HackR who is having some keyless works problems right now.

I was originally inspired to do this by Ajoesmith who's tutorial on the Replica Collector site gave me all the info I needed for the subdial freezing.

The Keyless Works info came from a combination of the ETA 7750 tech guide as well as some other tech docs I have kicking around.

Thanks to RWG...the place to be, I was inspired to go the next level in watch fixing (beyond changing straps and sizing bracelets). By the way, you'll see 2 different watches used in this tutorial because pics the best pics were found using a combination of documented efforts.

Without further delay...excuse the crappiness...and lack of prose...we're into the business lickity-split. Oh...and yeah...my fingernails need clipping...useful for peeling dial strips though.

MOVEMENT: Sea Gull ST1902 (aka Venus 175, Lemani Manual Wind)

PROBLEM:

• 
  
• 6-o-clock subdial on the ST1902 is mated to the hour wheel instead of being a chrono totalizer function
  
• Crown would not insert properly or wind movement
  
• Movement would not run
  
  
  SOLUTION:
  
  • 
    
  • Freeze 6-o-clock subdial
    
  • Check keyless works
    

Tools Used

Open Bracelet

Open Caseback

To open the caseback, I use a cheap Rolex caseback kit I picked up plus the Bergeon 29.5mm die purchased from H.W. Perrin in Toronto.

The Movement...lovely!

Remove the Stem

With the crown unscrewed and in the winding position, I use my springbar tool and depress the stem release button gently, while turning clockwise and pulling out the crown.

Remove movement holder screw #1

Remove movement holder screw #2

Remove both movement holder tabs

Remove the movement gently on a decasing pad

Mount movement in movement holder...note chrono second hand is not pointing at 12-o-clock

NOTE: 6-o-clock subdial hand is already frozen and sort of reset already (not pointing right at 12-o-clock in the pic...it has since been resolved). On the watch "out of the box" it will be parallel to the hour hand so it can look kind of funny as none of the other chrono functions will be running but the 12 hour totalizer is pointing to the hour of the time unless it's frozen.

Sea Gull had talked about making a true 3 register chrono function ST19, but have yet to do so.

Install Bergeon 6938 dial protector

Use Bergeon #1 hand remover tool to remove the chrono second hand (or use a generic cheapy)

Chrono second hand off

NOTE: Dust on dust on dial protector. This is to ensure similar conditions to Chinese assembly plant to make sure the movement operates properly as per factory conditions and specs.

After removal of the chrono second hand, remove the minute and hour hands using the same tool. For the subdial hands, you will need to use a carefully dressed hand tool (i.e. filed) or a Bergeon #6 I believe (I don't have the #6) because the small hands are pretty tight to the dial so you need thin claws on the puller to grab the hands effectively.

Hands off

Unscrew dial feet (2 sets)

Dial feet screw

Dial removed reveals cover plate

Arrows indicate cover plate screws that need removal.

Screws removed

Cover plate removed

Note the faux chrono 6-o-clock subdial is in fact merely hand attached to a wheel with a pinion connected to an intermediate gear that is connected to the hour wheel.

To Freeze the Subdials: These 2 brass wheels are merely removed with tweezers as the cover plate holds them in place.

Wheels removed...not grease / wear marks

Add dial strips where the pinion wheel sits

Stick pinion wheel into dial strips (or use dial dots...whatever)

Note buggered keyless works

Proper Keyless Works

If you note 2 pictures up, the setting lever jumper is not correctly hooked onto the setting lever. This likely was caused from pulling the stem out in the time-setting position and popping things out place. You can also bugger the keyless works by pressing the stem release too hard.

To reset the keyless works, merely hook the setting lever jumper back on the setting lever post.

I also had the problem that the winding pinion fell out somehow. To put this back in, use a screwdriver or springbar tool to push the spring loaded sliding pinion to the left, and drop the winding pinion back in place so the teeth on the face of the winding pinion mate with the teeth on the face of the sliding pinion.

Easy peasy.

Once the keyless was reset, everything worked properly. I was able to reinsert the stem properly and proper function allowed the movement to run again instead of being locked in the time setting position. I was lucky!! On other movements (not the ST1902), you might have to re-position the yoke between the winding and sliding pinions to reset things.

Put the cover plate back on...and install the screws.

Screw back on the dial using the dial feet as guides...or mount using dial strips / dots if the feet break off or you change to another dial without feet. 3 register movements are easy as you have 4 small reference pins to ensure proper centering of the dial. Movements with date functions help as well...but can be a bit finicky to centre still.

It is harder to center the dial on movements without dial feet when you don't have additional registers and will have to use dial hour markers lining up with stem insert holes or other movement references to ensure proper centering.

Dial back on

Mount running second hand

I use Rodico to pick up the hands.

Use hand pressing tool to mount hands.

I used JMB's great hand tools from THIS THREAD.

Do the other subdial hands

Mount the hour and minute hands

The beauty of mounting the hour and minute hands on a movement WITHOUT a date feature is that you don't have to worry about the position of the hour and minute hands as they can be manually set when setting the time with no "rollover" coordination with midnight to worry about...so just plug them in, set the time and go!

Check for hand clearance

If the hands are pressed too deep, are not parallel to the dial surface or are bent, they will hit each other. you may have to try and level out the hands with your hand pressing tool or try and straighten the hands if they are bent.

Mount the chrono seconds and admire your work

NOTE: The chrono seconds hand does not mount around anything, but has a post that fits inside the pinion. This is best positioned through a loup using Rodico and then pressed once centered correctly.

As well, you'll see the chrono second hand is properly pointing to 12-o-clock. This is a bit finicky to get set properly and WILL take a bit of trial and error so keep that loupe and hand puller handy!!

ANOTHER NOTE: When installing the chrono second hand, you should make sure the stopwatch is not running, and that the chrono reset pusher has been pushed otherwise you will find your perfectly centered hands are NOT pointing to the top after you install everything.

Re-case movement

Put back in movement holder tabs and screws

Re-insert stem

Blow off dust...Rodico off finger prints, oil and grease. Grease gasket

Re-install caseback

I find the rubber tool is easier to handle for re-installing the caseback.

Re-install bracelet

Would you believe I forgot to take final pics of the watch? Whoops!!

Hope you found this useful. Good luck...and let me know of comments questions, or things I should have done.

[Utheman]

Wow! Great tutorial. Thanks Toad!

ww

[budda]

thanks for the tut very helpful

[highoeyazmuhudee]

NICE! come here Moon watch...

[sander]

[jmb]

Fantastic tutorial, your pics turned out a lot better than mine when I'm trying to tear something apart and click the shutter at the same time! :-P

[Ronin]

That was incredible! Great job!

[ubiquitous]

Excellent play by play, S! Job well done!

[RWG Technical]

Excellent write up and pictures. You covered all the basis and details, well done.

[Toadtorrent]

Thanks Ubi and Zig!!! I wasn't sure if I got the parts named right...glad it makes sense!

[kbh]

Thanks. That one was certainly worth Bookmarking. Very well done.

[HauteHippie]

Wow, good stuff as usual, Toad... I will have to come back and read the whole thing later, but it's clear that this is nothing less than a fantastic guide!

[dluddy]

Great tutorial post Toadie...

One question.....

How did you get the dial to change from Black to Silver to Black again

[Toadtorrent]

How did you get the dial to change from Black to Silver to Black again

Ask Ubi...it was his dial. It magically appeared in the mail (THANKS AGAIN!!) and more magic happened.

[hackR]

...I am not a watchmaker...but a hack...inspired to make a tutorial to help others out including my bud HackR who is having some keyless works problems right now.

hey - I resemble that comment?!...

Toad -- wow...simply wow!...

a lot of work and learning went into this -- this i know...thanks for showing us how this can be done by novices...you have to start somewhere...

now i know i'm going to get some pressure to try this on my Omega BA...for both frozen subdial and frogged up keyless works (pun intended, of course... )

i just wish someone packaged up an entire kit of tools/supplies to get someone started...would make it great to order a single kit...

S - seriously well done... but a lot less enticing to women then showing them how to use the Navi slide-rule!...

well-done...

R-

[andreww]

Great post mate! I didn't realize you were getting so deep in to watch repair! I guess I'm going to have to send my stuff to you instead of Boots soon

[Pugwash]

Amazing! Nice post, well put together. Great photos, too.

[Rubi]

Great tutorial - thanks a lot! Worked nice on my Moonwatch (I ran into the same problems, so thanks for the hints).

One little problem: the watch runs a little fast now (about 2 secs per hour), could somebody please tell me, how to fine-set the movement?

Thanks!

[highoeyazmuhudee]

Great tutorial - thanks a lot! Worked nice on my Moonwatch (I ran into the same problems, so thanks for the hints).

One little problem: the watch runs a little fast now (about 2 secs per hour), could somebody please tell me, how to fine-set the movement?

Thanks!

did you bump the regulator or beat error lever? did some debris enter the movement?

[Rubi]

did you bump the regulator or beat error lever? did some debris enter the movement?

I think I did. Here's a picture I found that helped me solve the issue:

(unfortunately I can't post any images or link, it was great, if a mod could edit)

[Ephry73]

Where did the dial come from that fits the St19 movement? Is there a difference between the a7750 dials and the ones that fit the St19?

E

[gpvecchi]

Where did the dial come from that fits the St19 movement? Is there a difference between the a7750 dials and the ones that fit the St19?

UP! Very interested!

[gasdoc]

Bump for an awesome old thread. I used the pics to fix my keyless without even removing the dial or hands. I just put the lever back into place from the side of the movement.

Thanks!!!

[shaunie_007]

Great thread.  I just froze the hand on my Speedy moonwatch, but now the big chrono seconds hand flies off every time i reset the chrono.  I think i may need a new big chrono hand.  Other than that this tutorial covered all the bases, even walked me through when my keyless works went awry.  Just really need to figure out the chronograph hand situation.

[Skywatch]

Fantastic detailed tutorial. Thanks for taking the time to post such a great resource.