Removing an old 12 sided case back

[linux]

I purchased a training watch on ebay, a Dorset which I came to find out was made either by Oris or Benrus and sold by a department store.  It has a 12 sided back spaced at 29mm from side to side.

I can't get it off.  I started with the 8-ball, tried the jaxa tool, looked in my tools for hand wrenches but only have a set of 10-sided and no "sockets".  The shop tools like an adjustable wrench or automotive socket probably won't work.  It's a beater watch so I don't care too much if I have to use brutal force.  I guess I can always try the super-glued nut on the back.  I did see a reference to using suction cups, I think with a Bergeon 5700 but they're pretty expensive and I'm not even sure they would work.  I also searched around for a 12 sided 29mm tool for watch backs but to no avail.

Anyway, thought I'd ping the community and see how you'd approach it.  I've attached pics of the watch.

 

 

[Neverenoughwatches]

3 hours ago, linux said:

I purchased a training watch on ebay, a Dorset which I came to find out was made either by Oris or Benrus and sold by a department store.  It has a 12 sided back spaced at 29mm from side to side.

I can't get it off.  I started with the 8-ball, tried the jaxa tool, looked in my tools for hand wrenches but only have a set of 10-sided and no "sockets".  The shop tools like an adjustable wrench or automotive socket probably won't work.  It's a beater watch so I don't care too much if I have to use brutal force.  I guess I can always try the super-glued nut on the back.  I did see a reference to using suction cups, I think with a Bergeon 5700 but they're pretty expensive and I'm not even sure they would work.  I also searched around for a 12 sided 29mm tool for watch backs but to no avail.

Anyway, thought I'd ping the community and see how you'd approach it.  I've attached pics of the watch.

 

 

Not all faceted backs are screwbacks, some don't even remove at all. So anyways what do we see on the case at the left hand lug ?

[JohnR725]

it would be really nice in the pictures if we had one a little farther back where we could see the entire watch and it's back. As opposed to I'm going to have to guess it looks like the writing is not centered perfectly or straight up-and-down which is what you would typically have with a non-screw off back. So probably this screws off and at one time you had a special wrench just for this.

but I really would like to see a better picture back out a little bit they just can't quite see what I want to see.

 

[HectorLooi]

You'll probably need a Breitling or Panerai caseback tool.

 Opener Repair Tools for BRL Panerai OMG RLX IW
https://a.aliexpress.com/_mLx25AT

But I usually just grip in a very big adjustable wrench and apply a lot of downwards force to avoid slipping and scratching the cover. Usually works.

But failing which, you can glue a huge nut to the cover and use a wrench.

[AndyGSi]

Looks to me like it's a screw back of sorts but only requires a slight rotation with the tab in the slot to unclip.

I'd just used a 29mm spanner vertically on 2 of the tabs but don't suppose you'd have such a spanner.

[rehajm]

…the glued nut works well and also cheap. I’ve had to do it a couple times. I use a socket wrench instead of a spanner…

 

Edited November 26, 2024 by rehajm

[oldhippy]

This is the Jaxa tool you need and its vice not that single handed one. It never failed with me to open cases such as what you have.

[HectorLooi]

1 hour ago, oldhippy said:

This is the Jaxa tool you need and its vice not that single handed one. It never failed with me to open cases such as what you have.

That is a very unusual Jaxa tool. Most of them I've seen only have 3 jaws.

Although the Jaxa was among the first tools I own, I've never really gotten comfortable using it. I just can't get used to the handle coming out from the side. I prefer a tool that is torqued axially.

Maybe I should give it another try.

[oldhippy]

I think the new type just have a single handle, which must be hard to use without a vice. Here is a photo of the vice. Don't forget there are also cheap imitations of the tool from China and God knows where.  

 

Edited November 26, 2024 by oldhippy

[linux]

Here are some more pictures not taken with the microscope.  I tried again with the jaxa and a case holder after seeing old hippie's photo, but no joy.  I also found an automotive wrench with 12 sides/12mm.  Huge tool but it's not meant to slip over a nut with such small (vertical) edges.  So rather than shell out $25 for a $20 beater watch, I'll take the watch into the hardware store and try it out.  Pretty sure it won't work.

 

[tomh207]

It does look like it should come off with a partial rotation with lugs lining up with the equidistant slots around the edge of the caseback as @AndyGSi suggests.

 

Tom

[linux]

6 minutes ago, tomh207 said:

It does look like it should come off with a partial rotation with lugs lining up with the equidistant slots around the edge of the caseback as @AndyGSi suggests.

 

Tom

Sort of looks that way.  Has anybody seen a caseback like this?  In any event you'd think that there had to be a tool available when they manufactured the watch, but I can't find anything so far.

[AndyGSi]

I'd expect you'd have to put some downward force on it as these appear to be tabs that slide under the case.

[HectorLooi]

The tool would probably have looked like this.

Did you check out the AliExpress link I sent in an earlier post?

[JohnR725]

On 11/25/2024 at 4:59 PM, linux said:

Benrus

if you go searching for something like the term above in case ranch you will find something like this

it's one of the interesting problems of watch companies there are lots and lots and lots of variations of stuff including how back's on. It's like the picture above of all the various case wrenches typically if you require old watchmakers stuff you'll end up with a huge supply of those it typically you'll never use almost because it was a limited for one company and that was the end of it.

2 hours ago, linux said:

I also found an automotive wrench with 12 sides/12mm.  Huge tool but it's not meant to slip over a nut with such small (vertical) edges. 

 

On 11/26/2024 at 12:17 AM, HectorLooi said:

But failing which, you can glue a huge nut to the cover and use a wrench.

the alternative to using the wrench on the case back itself is epoxy a large nut to the back and unscrew that. Although the word unscrew is not quite appropriate as it only needs to move a little bit the free the tabs. Then the epoxy is really easy to get off you just dropped the thing of boiling water and usually not that much pressure is required and I will pop off. That's also really nice way of removing glass crystals and have been epoxy into watch cases is you just boil them and they will just push out.

Then the other probably may be facing is that a lot of times the gaskets disintegrate and become super sticky like glue which is one of the reasons you may be requiring so much forced unscrew it

[linux]

3 hours ago, HectorLooi said:

The tool would probably have looked like this.

Did you check out the AliExpress link I sent in an earlier post?

I did but didn't find anything suitable.  Checked ebay also, and the Paneri backs are too big.  I also went to home depot with the watch and tried to fit a "massive" 29mm wrench over the back.  The 12 sided closed end would not even engage due to the sheer size, and the open end (2 sides) were actually a hair small.  Sigh.  I think I'll try the super-glue/nut trick next.

[linux]

Hector, I looked again and realized that you pulled them off of Ebay.  Thanks.  I made contact with one of two people selling these "spoonz" and he measured one that looked like it could work, so I'm thinking about it.  I think i may tinker a bit more and try to superglue/nut trick first.

[linux]

So I only had a small nut, about half the diameter of what I thought would provide enough torque to break it loose.  I slathered it with superglue, set it off center unfortunately and let it sit for 30 minutes.  Then I nudged a big adjustable wrench on it and voila, it worked and I didn't have to apply much pressure at all.   I fully expected the nut to come off.

It only had to turn a small amount and it popped out of the 3 equidistant notches.  So now I'm a believer in the superglue nut technique.  Here are some pic's:

 

What a strange design.  And under magnification it says cal 1115, which I take to be the movement, Swiss and Montgomery Ward.

Edited November 29, 2024 by linux
grammer

[mbwatch]

1 hour ago, linux said:

And under magnification it says cal 1115

Ronda RL 1115, common in a lot of skindivers.