Clone 2836-2 Broken Stem - Extraction Ideas?

[minty007]

Hi gang. I have a problem that requires your sage advice...

The stem broke on my Timewalker w/ a clone 2836-2. It snapped cleanly at the base of the crown, which means that it broke a few mm inside the tube. As you can see in the picture, the MB case design leaves next-to-no room for stem access next to the movement and the tube is just narrow enough to prevent narrow tweezers from getting to the stem from the outside. Lack of access is my issue. Since the movement has very little side-to-side clearance inside the case, I don't think I have enough room to cantilever the movement out with the stem remnant in place. Nor can I think of a way to get in there to cleanly & safely snip the stem off at the edge to pull the movement.

I'd be most grateful for any creative ideas you might have as to how to get this thing apart...

 

[KBH]

Can you possibly unscrew and remove the crown tube and then pull it out?

 

[junbug5150]

Hi gang. I have a problem that requires your sage advice...

The stem broke on my Timewalker w/ a clone 2836-2. It snapped cleanly at the base of the crown, which means that it broke a few mm inside the tube. As you can see in the picture, the MB case design leaves next-to-no room for stem access next to the movement and the tube is just narrow enough to prevent narrow tweezers from getting to the stem from the outside. Lack of access is my issue. Since the movement has very little side-to-side clearance inside the case, I don't think I have enough room to cantilever the movement out with the stem remnant in place. Nor can I think of a way to get in there to cleanly & safely snip the stem off at the edge to pull the movement.

I'd be most grateful for any creative ideas you might have as to how to get this thing apart...

Here's a way to remove it without having to remove the dials and hands. It's pretty straightforward and takes 10 min max

https://www.youtube.com/watch?v=0b83l-1DmlQ

 

[minty007]

Can you possibly unscrew and remove the crown tube and then pull it out?

Here's a way to remove it without having to remove the dials and hands. It's pretty straightforward and takes 10 min max

https://www.youtube.com/watch?v=0b83l-1DmlQ

Thanks very much guys. The case shape make tube removal questionable, but I'll carefully try that first to leave the movement intact. If no luck, I'll dive under the bridge per the video and get at the stem that way - it looks like something I can handle pretty easily. I'll let you know how it goes.

 

[junbug5150]

Thanks very much guys. The case shape make tube removal questionable, but I'll carefully try that first to leave the movement intact. If no luck, I'll dive under the bridge per the video and get at the stem that way - it looks like something I can handle pretty easily. I'll let you know how it goes.

Good luck!

 

[minty007]

And I assume getting the nub out of the crown to salvage it is impossible?

 

[junbug5150]

Yeah, sorry to say you're probably gonna need a new crown.

 

[minty007]

Yeah, sorry to say you're probably gonna need a new crown.

I have a slew of screw extractors... but nothing even close to one that small! I'll work on sourcing a replacement crown...

Thanks again for the help

 

[KBH]

You can dissolve the stem in about 5 to 10 days with powdered alum and water mix.

 

[DreadPirateRobert]

Maybe a fat glob of superglue( or JB weld) on the broken piece in the crown? The after letting it cure just pull it out as you would naturally? I've done that on a standard drywall screw that lost its head.

 

[minty007]

You guys are awesome. Thx for the ideas!

 

[KBH]

Another idea about removing the screw from the movement is to get a stem extender which would just screw onto the old stem threads, although I think Junbug's idea is still the easiest.

 

[minty007]

You can dissolve the stem in about 5 to 10 days with powdered alum and water mix.

Not being even remotely a metallurgist, are the stem and crown metals dissimilar enough that alum would dissolve one without affecting the other?

 

[KBH]

Yes. It has no effect on stainless steel and the stem is hardened steel which rusts away to nothing in no time. I bought that alum on Amazon a few years ago.

 

[minty007]

I'll give the alum a shot. Looking closer at the crown, the break occurred slightly below (recessed) the outer edge, so attempting Hdresden's good idea of creating a new head would prove difficult.

 

[minty007]

OK, I'm trying the alum soak on the crown and thought I'd document the process in case it works and can help someone else.

I picked up the alum in the spice section of the local grocery. Cheap and easy to find.

Doing a little research, I found a few tips for the process. The first was to protect any non-metallic parts against potentially discoloring vapors by lathering them w/ wax or a petroleum-based product. Since my crown has a plastic Montblanc logo tip, I covered it in an industrial-strength hand cream which uses paraffin wax as its base...

The second tip was to use heat throughout the process to stimulate the reaction. I started with some boiling water to dissolve the alum. As to the amount/concentration, it was suggested to make it as super-saturated as possible by adding the powder slowly until it no longer dissolves when stirred. I then placed the crown right-side-up in a small beaker with just enough solution to cover all but the plastic tip...

Finally, I placed the the beaker on an electric mug warmer to keep the solution warm and the reaction going...

Now, we wait patiently while it does its thing. Since this is a relatively weak acid, it can take some time (days...) to work, depending on the composition of the metal it's attacking. I'll keep you posted as I check in on it (and in the meantime I'll have a chance to go after the other end of the stem caught in the movement)...

 

[minty007]

Update, T+1 hr:

Well, that didn't take long to get my first finding. Left uncovered, the heated acid solution evaporated within the first hour. The beaker has been refilled and is now covered with a rubber stopper (of sorts). The experiment continues...

 

[junbug5150]

Update, T+1 hr:

Well, that didn't take long to get my first finding. Left uncovered, the heated acid solution evaporated within the first hour. The beaker has been refilled and is now covered with a rubber stopper (of sorts). The experiment continues...

Whoa! You took it up a notch! GL man!

 

[junbug5150]

Did you ever get that stem out of the movement?

 

[minty007]

Got sidetracked w the alum, but hopefully I'll be able to dive into the movement tomorrow. I'll post the success or failure.

Sent from my CONTROL shoe phone inside the Cone of Silence