I have 3 watches with this case. The first one fell off my wrist when the strap broke and I had to open it to fix the balance staff. I had a heck of a time getting it open (took like 45 min) but I assumed it was because of the fall. Eventually my other two needed service too and these I could not get open with a quality (several actually) case knife. Finally I had enough and decided to start the case back off with a few taps from a hammer and screwdriver. Once widening the gap I was able to open the backs with a kinfe with a loud pop. These are designed to be waterproof and there is no gasket so they are quite tight. Because they are so well sealed you are probably fighting a vacuum.

There must be tens of thousands of these watches out there and I have never heard anybody say they had difficulty opening the back. I'm sure there are dozens of members of the forum with this watch. Does anyone have a tool they like or a specific tip or trick for getting these open? The rest of my case backs I can open in just a few seconds.

 

I use a blunted Stanley knife blade - take the points off (you don't want them snapping off and firing themselves into your eyes) and blunt it slightly on a stone.

 

I remove the straps/bracelet and then hold the watch upright on a block of soft wood that has a hole to take the crown
I start with a thin Gem style blade. Find the seam and then gently push the blade in while slowly rocking it along the seam

And the like Stewart, when you have a bit of a gap, a Stanley blade is next, repeat the rocking procedure, then try a fine knife blade.
You will eventually be able to get a case knife blade into the gap and use it to enlarge the gap until it opens.

Alway use a rocking motion and allow the wedge of the blades to do the levering, never try to prise the back open.

My tools in order of use from top to bottom.

 

The watch is now running absolutely perfect and is re-cased. But naturally after 12 hours or so the sub second hand caught the back of the dauphine hour hand. It is mounted a smidgeon too close to the dial and I have to open it again.... Naturally.

I have the stanley blade as well as a thin pocket knife blade. I also have the bergeon knife. I'm a little leery of using the sharp ones; if that blade should slip out of groove I don't feel like getting stitches. I'm still working on it. I hope not to resort to using the hammer and screwdriver to start it.

 

In a similar vein, am I correct in thinking that to shift a stuck screw-in back you can use a reasonably soft rubber hand ball? I'm positive I heard this somewhere. (Apologies if it was in here)

 

Yes - I've heard that sticking and twisting a piece of tape works as well.

 

The balls are nice and cheap but make sure you get one that has a slightly tacky feel to it. As a tip, keep it well inflated and wrap it in cling film when not in use because they are a dust magnet.

That's why I just take the edge off of the blade.

 

I use a number of tools for snap back cases - these are the two that I use the most:



The red one has a thinner blade than the blue one does. I also use a swiss army style case knife I was given by a supplier at one point, and it has a case knife blade as well as a regular pen knife blade, and I have used both for opening cases. You should also keep a pack of single sided razor blades handy - these are sometimes needed when the gap is very small.

As noted never pry, just get the appropriate thickness blade into the gap, and open it as far as that tool will go, then move to the next thickest blade. Keep going until the back is simply free of the case.

It's very rare that I would have to take the step of using a hammer. Usually only when cases are corroded shut, and this is where the pen knife blade on the Swiss army knife works well. Just a couple of taps on the back edge of that blade with my watchmakers hammer and I can usually get the blade into the gap, and then proceed by opening the gap.

IMO keeping the various blades sharp is better, but of course I do this all the time and there is skill involved in not cutting yourself. Okay probably less skill and more "looking/thinking before doing" involved really...

Cheers, Al

 

The Bergeon blade is probably too thick for this application. I probably need some razor blades and thinner case knifes. I do mean light taps with a watchmaker hammer and .8mm screwdriver, not pounding it with a 14oz hammer and chisel. I have lots of knifes, but I think I should try these seiko ones as well as get a pen knife. This is all good stuff. Good to know it's not just me. These are a PITA to open. It looks like Al Archer and Jiminoz have similar techniques of using successively larger knifes until it's open.

 

The one with the Red handle seems to work on my 2975's

 

View attachment 127493
What do y'all think of this generic Horotec opener? It's $60 vs the Swiss one above which is $350. I have a Horotec press which I love, but I don't want to spend this for a tool I will use 2 times a year.


I have this tool and it's probably meant for cases such as this, but I found it very awkward to use. Maybe I should give it another try.

I found the red Seiko knife which others seem to like. I may try this one too. But I can buy all these tools and may not need them for a long time.

 

double post

 

As a well-known knifemaker once said to me, regarding the Colt 1911 he always carried, "Better to have it and not need it than to need it and not have it."

 

I have a Horotec case crab and is my first port of call if the Stanley knife blade won't work.

 

Personally I don't think it's needed, as I have never had a case I could not open with the simple and inexpensive tools I have shown above. And keep in mind I am doing this for a living, so if I thought a tool like this would make a significant productivity increase and would pay for itself, I would get it.

I know some people look at what watchmakers have and it's easy to conclude that you need a lot of fancy tools to do this kind of work. Yes tools are very important, and having the right tool for the job is always a good thing, but you can also get caught up in tools. Personally if I can do the job without having to spend $350 for a tool (again the tools I listed above are very inexpensive) then I will.

One thing to keep in mind is just because a well known brand makes or distributes the tool in question, that doesn't necessarily mean it's a good tool. A great company called K&D made great staking sets, but they also made "staff removers" which punch out the balance staff - a big no-no. L&R make great ultrasonic tanks and cleaning solutions, but for years sold "solo-lube" and "duo-lube" products that "cleaned and oiled" in one easy step...of course these solutions are garbage.

The only way I would spend the money on something like this tool is if a brand I had an account with mandated the purchase.

Cheers, Al

 

Well said Al, but you have to admit there is a certain pleasure in a well made tool that works. A few things I'm glad I spent extra on are quality hand levers, assorted hand presses, and a case/crystal press. With that said, I opened it this time with a utility blade and a heavy leather glove (to protect my pretty hands) in about 10 seconds. It was all about using a thin enough blade along with the rocking motion (thank you JimInOz). That is a neat technique. I don't think I need to buy any more tools.

 

I think most of the thanks should go to Al, his posts over the last few years has been a free education for tinkerers like me.

I simply show what I've learnt.

 

Certainly good tools are a must when doing this work, but there is overkill as well. If a tool does not produce better quality work, or improve productivity, then for me it's not a good purchase.

Things like good hand levers and a good hand press have a direct impact on the quality of the work, so they are worth spending more money on - my hand press was certainly not cheap...but it came in a nice fancy wooden box with an Omega logo on it, so it must be good!

Seriously, it is good, and I use it every day, so worth dropping $2k+ on it. Hand levers don't have to be expensive, but they do need to be well designed - I use the VOH levers after trying many brands and they are by far the best IMO:



But the Horotec case thingy to me would not be a good purchase as I have said. For others it might be, but it's not needed for my work. I have never thought "Boy I wish I had that tool here now!" As you have found, the thin blade works well, and if you use the right technique, even tough cases can be opened with the simple tools.

Cheers, Al

 

When I fool around with pocket watches I use the simple hand-held hand-press tools---plastic-tipped metal rods with holes on the end---because they SEEM to offer a little more opportunity to fiddle around and get the hand perfectly aligned before pressing. What do you consider to be the main advantage of the Omega tool?

 

Well, the number one advantage is that the runner used to actually press the hand in place is not hand held:



Using a proper press that keeps the runner perpendicular to the watch dial helps you install the hands correctly, so making sure they are parallel to the dial, and have the proper division (spacing between the hands, and between the hands and dial).

This press comes with 8 different runners, and the tips of those runner all have different sized holes in them (there is a rotating stand for them not shown - like what you have with a set of screwdrivers), and there are spare tips included as well. Omega provides information on what runners to use for specific models, but I have most of them memorized.

The press has a recessed area in the base that centers the movement holder in the press, and if you use that the center of the movement will be under the runners for watches with hours/minutes, and seconds in the center of the dial. In addition, there is a "decentering" plate that is used when you have a movement with multiple locations on the dial where the hands are installed, like on the Speedmaster shown above. The movement holder has holes on the underside where each hand goes, so I can place whatever hand location on the dial under the runners as needed. Of course the movement holders are sold separately, and I have a few of those:



Not all for dial side work, some for train side, and others are for special things like checking/oiling co-axial escapements, etc.

Cheers, Al