Clone 2836-2 Broken Stem - Extraction Ideas?

[minty007]

T+1day: No heat overnight since I wasn't able to babysit the process. I had to slightly renew the solution this morning, which gave me the opportunity to check the process. It's actually working. I've dissolved a little more than 1mm of broken stem so far. No, not much progress... but progress. And I was told I needed to be patient!

No chance to tackle the movement yet. Likely this weekend if the schedules cooperate.

 

[Raddave]

Nice dude ! cant wait to see how this works out.

couple tips i can think of.....id have dripped candle wax on it instead of that cream, but your way looks to be ok too.

while you are not present, maybe you can set it on top of your refridgerator or water heater, wont be as good as Mr. Coffee but it wont be unsafe either !


Keep us posted !

 

[minty007]

Nice dude ! cant wait to see how this works out.

couple tips i can think of.....id have dripped candle wax on it instead of that cream, but your way looks to be ok too.

while you are not present, maybe you can set it on top of your refridgerator or water heater, wont be as good as Mr. Coffee but it wont be unsafe either !


Keep us posted !

Thanks for the tips - I'll try to implement both of them!

T+5 days: So the heat (or lack of it) definitely makes a difference in how quickly the alum solution does its thing. The heat was off during the last 2 1/2 days (over the weekend) and the progress was about equivalent to one day with the heat on. I'd estimate that approx 2mm of the stem nub has now been dissolved. It's tough to tell how much is in there, but I'd like to think I might be about halfway through it.

The heat is going back on today. And I'll look for a convenient and safe source of overnight/weekend heat as well (i'm running this experiment in my office so I need to get creative). The patient cooking continues...

 

[KBH]

Pretty soon the last big chunk should fall out, or stick a pin or something in and wiggle it around and the rest may fall out. The threads have probably already rusted away.

 

[minty007]

Pretty soon the last big chunk should fall out, or stick a pin or something in and wiggle it around and the rest may fall out. The threads have probably already rusted away.

Thx, I've been poking at it w/ a needle. No major movement yet but I was hoping that the threads would go first, allowing the rest to plop out. I'll keep at it...

 

[Psambrose]

This was kind of like reading a good book, only to find the last two chapters are missing...

 

[minty007]

Thanks for the kick!

Sorry guys for going MIA - while I was waiting for a new stem to arrive I had to do some unexpected traveling so the continuing repair job went in fits and starts and I and forgot to update the project thread.

Here's where the project stands...

It worked! Patience was the key, but alum was the magic potion. It dissolved the broken, embedded metal without damaging the internal threads needed to re-attach the replacement stem. New stem (Esslinger) cut to length and a perfect fit. The one downside - despite the wax used to protect the white MB star on the crown, it yellowed slightly from the alum off-gassing. I've tried to brighten it up with some concentrated peroxide without success, so I'll move on to a little stronger bleach to see if that may work. If all fails, it's not that big of a deal since the discoloration isn't very significant.

Thanks to [MENTION=93965]junbug5150[/MENTION] 's YouTube video link, I was able to partially disassemble the movement and extract the rest of the stem. Damn, some of those internal screws are microscopic! It all went back together fine, with movement running strong, then...

While fine tuning the stem length for proper crown fit - pulling the stem out and back in each time - the hack mechanism malfunctioned and the darned second hand wouldn't start running again. So, that's where I am now. Fortunately, the same repair video shows the hack repair, so I'm going back in to the movement's innards to give it a shot. This time I'll shoot some pics for posterity's sake and post 'em here. That's my planned project for the weekend - I'll let you know how it goes... I promise! :wink:

 

[Raddave]

Two steps foreward, one step back.........thats how it goes in this crazy world of ours !

 

[junbug5150]

Glad the video helped!!

 

[minty007]

Well, despite my best efforts... no love was returned by the MB.

I dove in three times to check/re-position the yolk under the sliding pinion hoping it would reset the hack... but no go. So I had a decision to make - dive in even deeper to attempt my first full keyless repair (or worse), or call in the cavalry to make sure things get done correctly. Happy with what I've accomplished so far but frustrated by the amount of time already spent on this project, I decided I had enough and selected option two. I've sent the watch off to miracle worker Katt for a proper repair.

I certainly learned more about this movement and the creative use of chemistry through my efforts and I really appreciate all of the help and input from you guys along the way. It'll be nice to finally get this one back on the wrist...

Here's a parting shot of the partially-disassembled movement during my attempted hack repair (but notice the nice, snug crown position!)

 

[Raddave]

Check the hack lever

 

[minty007]

Check the hack lever

I attempted to check and re-position it based on what I could get at from the open backside, but it seemed that a more thorough investigation from the front of the movement was in order... and I wasn't in the mood to add yet another set of hands and dials to the workbench. I have too many perpetual works in progress already!

Katt will give me his take on the issue once he has a chance to evaluate. Then I'll know for sure whether I would have been in over my head to continue or could have actually fixed the thing w/ a bit more effort... I'll report back.

 

[minty007]

Once again, Katt has proven to be a wizard...

It turns out that my choice to send it to him was a good one. He had to go a bit deeper into the movement and found that somehow, the pivot on the escape wheel was damaged. A quick replacement with a new part, reassembly and proper lubing of all jewels then an overnight QC check to make sure all was well and Katt already has the watch on its way back to me. I only wish I could find that kind of stellar service from other providers in my life...

Here's a pic from Katt of the movement at its deepest stage of disassembly...

 

[KBH]

Your biggest F-UP was taking the train bridge off. There was no reason for that and it's very easy to break a pinion on one of the gear wheels, which you apparently did while trying to put it back together. Ask me how I know that. :lol:

Glad Katt finally got you squared away.

 

[Raddave]

Looking back at your pictures,

if you ever need to remove that bridge again, you should also remove the main barrel, the balance assy, and the pallet fork.
(after of course you let down the movement).

that way when you go to replace the train bridge, you can check the rotation of the gears, make sure they spin properly, and all the pinions are in their respctive jewel holes before you tighten down the bridge.

 

[minty007]

Your biggest F-UP was taking the train bridge off. There was no reason for that and it's very easy to break a pinion on one of the gear wheels, which you apparently did while trying to put it back together. Ask me how I know that. :lol:

Glad Katt finally got you squared away.

Looking back at your pictures,

if you ever need to remove that bridge again, you should also remove the main barrel, the balance assy, and the pallet fork. (after of course you let down the movement). that way when you go to replace the train bridge, you can check the rotation of the gears, make sure they spin properly, and all the pinions are in their respctive jewel holes before you tighten down the bridge.

Thanks guys for the tips. Despite my many years of collecting watches, this level of movement repair is pretty new to me. Despite the speed bumps, I've enjoyed the learning experience and I look forward to keeping it going. Hopefully others reading this thread and those like it are learning along with me and if new, will gain the confidence to try operating on their own watches.

I really appreciate all the help and support!

 

[Raddave]

Is that a scooby doo mystery machine in the background.......i sure hope its not carebears !

 

[minty007]

Is that a scooby doo mystery machine in the background.......i sure hope its not carebears !

Ha! Close... not carebears, but dancing bears!