Opening an Unopenable Caseback? ['72 Zenith Defy A3642]

[dpn]

Hello all,

I'd appreciate any advice you might be able to share here. This watch is well beyond my ability to service, and I'm having trouble determining what the correct path forward is. Thank you in advance for any suggestions on how to best proceed. I'm pretty freaked out.

Background: A few weeks ago, I bought a nice unpolished, 100% original Zenith Defy A3642. This watch was purchased new in Paris in 1972 by the seller's father, who recently passed away. Per the seller, his father wore the watch only briefly after purchase and put it into a safe where it sat for 40+ years. One of the reasons this watch was so attractive to me was the fact that it was pristine, and I planned on having it completely overhauled. I posted a little while back asking for input on a deteriorated crystal gasket that was visible in this watch, realized that it was beyond my skills to fix (in part because I couldn't find the correct Zenith caseback die), and made sure to discuss it with the watch repairer I sent the watch to. I sent the watch to someone who sounded to me to be quite qualified to overhaul this watch. He is described as "a highly-decorated skilled master watchmaker with over 37 years of classical watchmaking experience. Having been the Technical Director of Vacheron Constantin, among many other prestigious positions at brands such as Girard Perregaux, Breguet, Richemont, and more, [Name] can handle every watch complication that comes his way including tourbillons."

Unopenable Caseback: I received this status update tonight: "[Name] is trying his best but it looks like we may have to deny service as we are having a ton of trouble getting it open. Caseback gaskets have seized up and the watch is not water resistant so we cannot boil it off. We are gonna give it one last shot tomorrow."

Given the visible deterioration of the crystal gasket, I'm not surprised to hear that the caseback gasket has deteriorated as well. When I received this watch, I failed to open its caseback with a rubber ball ... but I didn't think that it would be described as unopenable. Has anyone run into this situation before, where a deteriorated gasket has jammed a caseback to the point that it couldn't be opened?  I hope that the issue isn't just that the shop doesn't have the correct hexadecagonal Zenith case back opening die. (I asked for confirmation that they have the correct die, and hope that I didn't offend them by asking that. It just seems like a fairly esoteric tool.) Are there any slightly more aggressive techniques that might work? Boiling the caseback off doesn't sound like a particularly safe technique, and I'd be OK getting some scratches on the caseback if that were the only way to get it open. What about gently heating the caseback to try to get the rubber gasket more malleable? I guess this is one of the hidden risks of buying a watch that looks pristine but obviously hasn't been serviced in decades.

What's the Plan? This watch was a significant purchase for me. It's not a watch I'm trying to flip. I had (briefly) considered mailing this watch to the Zenith factory in Le Locle for service, but had ruled it out as likely to be significantly more expensive that other options with a significantly longer turnaround time. Given the puzzle of the unopenable caseback, this is sounding like a better option. It would probably be very expensive, but I imagine that the factory would have an original NOS caseback they would happily sell me for a very high price if there's no non-destructive means of opening the caseback.
 

Edited August 26, 2020 by dpn

[anilv]

I smell BS here, maybe he works on such high end watches and probably can't justify the time to work on a simple watch? Think about it, a service of a higher end watch (tourbillon) would be into four figures so this would be an hourly rate of close to 200USD?

I would try another watchmaker. Anyway if you have a problem send it in to Mark, the owner of this forum..might be the subject of another video!.

Anilv

[Ishima]

While i certainly don't know everything...
I've never heard of a deteriorated caseback gasket causing that much trouble, i struggle to imagine it could.
Also never heard of the technique of 'boiling a watch case back off' that sounds kind of... completely insane. 

Not to challenge their expertise, this may just be a case of "make something up that sounds convincing" because the truth is either too complicated or awkward to explain.

I don't know what to suggest than to keep looking around for other good repairers, I doubt this watch is impossible to open. 

Edited August 26, 2020 by Ishima

[watchweasol]

Hi If all other avenues end up in a blind alley and the only recourse is to open the case your self I would suggest heating up the case back in order to soften the gasket. use either a hot air gun (as used for heat shrink) or a large soldering iron to keep the heat as local as possible (confined to the case back).    This of course is a last resort.  One might consider immersing the watch in a shallow dish of spirit, enough to reach the case back seal and allow the spirit to soften the gasket.

It looks a beauty of a watch so be careful and no brute force whatsoever.

[dpn]

Thanks for the quick responses. The initial estimate was $650, so I doubt that it's a service cost issue. That said, the shop sort of specializes in higher end stuff and they might have just decided that it was too much trouble to be worth bothering with. I hope it's just that they don't have the correct die. Fingers crossed, and I'll update if I learn anything more.

Edited August 26, 2020 by dpn

[watchweasol]

Hi  I would be surprised if a high end watchmaker repairer had not got access to the proper tools, So it may be it too much trouble.  Be interested in the outcome.   good luck with the problem.  cheers

[watchweasol]

Hi Check this out, Its about removing a glued in crystal, but the methodology may well be applied ti your problem with the "glued" on back.           https://blog.esslinger.com/watch-crystal-3/              cheers

[JohnR725]

I don't suppose we can get a picture of the back of the watch?

[dpn]

27 minutes ago, JohnR725 said:

I don't suppose we can get a picture of the back of the watch?

I didn't take a good picture of it, but here's the picture from the seller showing the 16-sided caseback.

[JohnR725]

What has happened is the case back gaskets has sort of disintegrated and turned into tar like substance. It holds the case back on really really tight.

What you need is somebody who has a case back opener like the one below. What makes this holder interesting is you can hold the movement very securely in the vice. You change the jaws to the flat ones as you basically Have flat sides to grab. The lower it down and as the video shows you can move the or spin the locking ring which locks it in place. That means everything is Held really really secure and then you put a heck of a lot of pressure on the handles and if you're lucky the case back will start to rotate. As soon as it rotates a little bit then you twist the locking ring a little to release it and slowly can Remove the back. Sometimes though you might have to put a penetrating oil on the edge hoping that that might make things better.

Others in the past in this group have suggested things like gluing or epoxy glue something I a really big not and using a suitable ranch.

 

https://www.nielsmachines.com/en/precista-generic-bench-top-watch-case-opener.html

[AndyHull]

2 hours ago, dpn said:

Are there any slightly more aggressive techniques that might work?

Supergluing a large steel nut to the caseback will give you much more to grab hold of. You can dissolve the superglue back off with acetone, but don't get that on the crystal as it will cause damage. Also the superglue will typically fail before the watch case gets damaged if you start to go full gorilla on it. Boiling a watch sounds like a good way to make watch soup, but a very bad way to start servicing it.

[AndyHull]

1 minute ago, JohnR725 said:

Others in the past in this group have suggested things like gluing or epoxy glue something I a really big not and using a suitable ranch.

Superglue is probably safer than epoxy, but when things get really stuck, epoxy is an option. You may need to use a lot of heat on the caseback to remove epoxy though, or in some cases you can dissolve the epoxy with an aggressive solvent like  MEK.

Epoxy is not easily dissolved in the way that cyanoacrylate (superglue) is.

Glue the nut on so that it is concentric with the case back. I've done this a number of times with a good rate of success.

I have also encountered front loading cases with backs that appear to unscrew, but in fact do not. Check with a microsope to ensure there is actually a break between the front and the back, and that they are not actually case as one piece.

[eezy]

10 minutes ago, AndyHull said:

Boiling a watch sounds like a good way to make watch soup, but a very bad way to start servicing it.

[Nucejoe]

Given the right tool, it will open, no heat, no boiling .......

[jdm]

2 hours ago, dpn said:

The initial estimate was $650, so I doubt that it's a service cost issue..

That is a lot of money for servicing that kind of watch and not even being able to open it. Take it back and give it to someone else. 

BTW I am also of the party that uses the right die is possible at all. No problem applying a bit of heath all around with a 65W soldering iron. 

[HectorLooi]

Here is a watch that belonged to my late father. It was never serviced before. The caseback was so tight that it broke the jaw of my mentor's bench mounted caseback opener.

We sprayed WD40, we heated it with a microtorch, we dripped acetone into the threads, we superglued a nut to the back...

We didn't just go full gorilla on it. We went all out King Kong! It still wouldn't budge.

In the end, I used 5 ton epoxy and glued a really big nut to the caseback, mounted my caseback holder to my bench vise and used a 15" wrench on it. Finally it opened. Broke my caseback holder in the process. 

[dpn]

Great feedback and suggestions. I've asked for the watch to be returned, but the shop has asked for a couple of days more to keep trying to open it. They did confirm that they have the correct die.

[rodabod]

The bond formed by a perished gasket can be incredible. I used the nut + epoxy trick on a Smiths watch and with the case held in a holder inside a bench vice, my entire bench rotated with the watch... it did come off eventually, though from memory it may have required heat. 

[dpn]

So, the shop appears to have given up and they'll be returning this watch to me.

I am quite tempted to use one of the techniques suggested (gluing a bit nut to the caseback, specifically) to get the watch ready for a repairman to overhaul. I strongly suspect that almost anyone I contacted for this repair wouldn't be comfortable using the more aggressive techniques described in this thread, and I wouldn't ask anyone else to assume the risk of damaging the watch. If my three choices are to: (1) send the watch to Zenith for a long and expensive overhaul; (2) get the caseback off myself before sending it for a normal overhaul; or (3) give up on this watch, then I'm good trying (2) before resorting to (1) or (3). If nothing else, it'll be fun to try to get this caseback off myself. I will, of course, document my progress.

I do not know whether this is against the forum rules, so please forgive me if these two questions are inappropriate:

1) It was mentioned that the $650 overhaul quote I was received was quite high. What should I expect to pay for a vintage watch overhaul? (I'm hoping, because this watch moldered in a safe for 40 years, that all of the components other than gaskets and o-rings will be good with a cleaning and lubrication. Obviously replacement parts will increase cost significantly.)

2) Can anyone recommend a watch repairman? All things being equal, I would prefer to send this watch to someone from this forum. It'd be super cool if Mark were willing to have a go at this watch -- I'd love to see it in a video.) I am located in the US, but would be comfortable mailing this watch almost anywhere. Please PM me with any recommendations.

[Nucejoe]

The place to go is any zenith forum, Timezone has a dedicated subforum forum, where sellers, entusiast ...are having a ball. 

 

[JohnR725]

56 minutes ago, dpn said:

1) It was mentioned that the $650 overhaul quote I was received was quite high. What should I expect to pay for a vintage watch overhaul? (I'm hoping, because this watch moldered in a safe for 40 years, that all of the components other than gaskets and o-rings will be good with a cleaning and lubrication. Obviously replacement parts will increase cost significantly.)

Asking for prices is always interesting. There is a another discussion group out there that for pocket watch repairers they feel somewhere between 50 and $100 is a good price.

I see that you're in Sacramento? Do they have a minimum wage there? Or if you found a vintage automobile in a barn somewhere and took it to the auto shop would they charge you $100 to go over the engine? Fortunately based on pricing watch repair is not considered a skilled profession.

The reason I bring these things up is to properly service the watch requires a little bit of time and equipment possibly some spare parts it can't be done in 30 minutes so like Seattle has a minimum wages $17 we can't charge $20 to service a watch because there's other expenses Then 650 is approximately the going rate the service a high-end watch and it would probably include case refinishing if needed. This is around the price of servicing a Rolex watch. Minor little reminder here as high as you think that Rolex repair cost is if they think it's a vintage watch it's going to easily double or more. Someone was telling me Rolex now charges $1000 just to evaluate a vintage watch and I think my memories hazy I think it's actually more than that.

To get a better price you need to find the watchmaker directly. If you go to a jewelry store and they send the work out they typically double the cost

Then adding to niceJoe's suggestion See if there are any authorized Zenith people in the US. Go there Swiss website they should have recommendations find out what they think the price should be then that will give you the maximum you should pay for anybody.

Basically to get the best price online is an option. Or seek out watchmakers in locations that have a low overhead. Like in the middle of the country perhaps. Get out of the big city like I imagine if you went to downtown LA they probably charge you just to walk into the store because of the cost of the rent.

Oh and in case you're curious the $50-$100 price recommended in the other group some other people have suspicions that maybe the watch isn't disassembled maybe it's cleaned intact it saves a lot of time. I noticing it's really hard to find now in fact it's been discontinued for watch repair as far as I can tell is still make it for clock repair the used to have a final rinsing solution that lubricated the watch. So in the old days the production shops did not disassemble the most part ran the watch intact through the cleaning machine the final rinse had the miracle lubrication and just a little grease here and there and you're good to go was very cheap and affordable exactly what you're looking for. This is one of my amusements and watch repair you take your watch to a jewelry store they send it out all they care about is the price typically the watch comes back you can't see what's inside you don't know what was done but maybe got a really good price and you're happy. But you might also find a passionate hobbyist who just enjoys working on watches that just charges enough to cover supplies and conceivably they'll do a better job than the so-called professional watchmaker. Means you can't tell what you get for the price.

 

 

 

 

[jdm]

1 hour ago, Nucejoe said:

The place to go is any zenith forum, Timezone has a dedicated subforum forum, where sellers, entusiast ...are having a ball. 

Specialized forums are great for specific knowledge, estimates, collectors's chit chat, but there is no differece between servicing a Zenith or any other comparable mechanical watch? E.g. watchguy.co.uk, he works on anything. Same for Mark Lovick, same for thewatchspotblog. The same names made in a Zenith forum would be seen in any other. And then the directory by AWCI in case one prefers local business.

[dpn]

1 hour ago, Nucejoe said:

The place to go is any zenith forum, Timezone has a dedicated subforum forum, where sellers, entusiast ...are having a ball. 

 

Thanks. I am already quite active on Watchuseek in their Zenith forums. I was hoping for recommendations from folks who know what differentiates a good repair person from a poor repair person, for many of the reasons mentioned below by @JohnR725

1 hour ago, JohnR725 said:

Asking for prices is always interesting. There is a another discussion group out there that for pocket watch repairers they feel somewhere between 50 and $100 is a good price.

I see that you're in Sacramento? Do they have a minimum wage there? Or if you found a vintage automobile in a barn somewhere and took it to the auto shop would they charge you $100 to go over the engine? Fortunately based on pricing watch repair is not considered a skilled profession.

The reason I bring these things up is to properly service the watch requires a little bit of time and equipment possibly some spare parts it can't be done in 30 minutes so like Seattle has a minimum wages $17 we can't charge $20 to service a watch because there's other expenses Then 650 is approximately the going rate the service a high-end watch and it would probably include case refinishing if needed. This is around the price of servicing a Rolex watch. Minor little reminder here as high as you think that Rolex repair cost is if they think it's a vintage watch it's going to easily double or more. Someone was telling me Rolex now charges $1000 just to evaluate a vintage watch and I think my memories hazy I think it's actually more than that.

To get a better price you need to find the watchmaker directly. If you go to a jewelry store and they send the work out they typically double the cost

Then adding to niceJoe's suggestion See if there are any authorized Zenith people in the US. Go there Swiss website they should have recommendations find out what they think the price should be then that will give you the maximum you should pay for anybody.

Basically to get the best price online is an option. Or seek out watchmakers in locations that have a low overhead. Like in the middle of the country perhaps. Get out of the big city like I imagine if you went to downtown LA they probably charge you just to walk into the store because of the cost of the rent.

Oh and in case you're curious the $50-$100 price recommended in the other group some other people have suspicions that maybe the watch isn't disassembled maybe it's cleaned intact it saves a lot of time. I noticing it's really hard to find now in fact it's been discontinued for watch repair as far as I can tell is still make it for clock repair the used to have a final rinsing solution that lubricated the watch. So in the old days the production shops did not disassemble the most part ran the watch intact through the cleaning machine the final rinse had the miracle lubrication and just a little grease here and there and you're good to go was very cheap and affordable exactly what you're looking for. This is one of my amusements and watch repair you take your watch to a jewelry store they send it out all they care about is the price typically the watch comes back you can't see what's inside you don't know what was done but maybe got a really good price and you're happy. But you might also find a passionate hobbyist who just enjoys working on watches that just charges enough to cover supplies and conceivably they'll do a better job than the so-called professional watchmaker. Means you can't tell what you get for the price.

@JohnR725 You make some really good points, and thank you for taking the time to respond!

I'm absolutely not looking for a lowball price; I was completely fine with a $650 estimate to begin with. I sent a vintage Rolex into the San Francisco "Rolex Service Center" around ten years ago, and that overhaul was $850. As I've been learning how to disassemble and reassemble watch movements, I've really come to appreciate how *difficult* watch repair is. I don't want to send the watch to a butcher, and am more than happy to pay a significant amount of money for a quality overhaul. I was just curious about what an overhaul "should" cost, given the reactions of others to the $650 quote I received (which, again, I was fine paying). Of course, I don't want to unnecessarily overpay -- which is why I'm hoping to avoid sending this watch to Zenith's factory in Switzerland.

I think I need to apologize for asking about price on this forum. Please disregard my request for price and recommendations.

Edited August 27, 2020 by dpn

[jdm]

55 minutes ago, dpn said:

I think I need to apologize for asking about price on this forum. Please disregard my request for price and recommendations.

No need, no rules against that.

[dpn]

It's not that my question was against the rules of the forum, it's that it's out of place given the spirit of this forum. It would have been better placed in a watch enthusiast forum.