Tuesday, 27 November 2012

Making a Gold Bezel for a Vintage Omega.

Hello everyone.

Some time ago a customer brought in his old 18ct Omega automatic with a view to getting a new gold bezel for it. He assumed (fairly enough) that it would be a fairly simple matter of ordering the part from Omega. Unfortunately a little research on my part quickly revealed that this was a very unusual, probably hand made, probably Italian, gold case, and there was no way Omega were going to be able to supply any case parts at all. There wasn't even a factory glass listed for it. Some time in the past the original bezel had been lost, and a watchmaker had jury-rigged a repair by mashing an acrylic glass into the case and then clipping a piece of 18ct gold wire around the outside. This makeshift bezel could actually be quite easily removed with a finger nail, and not surprisingly the customer was hoping for something better.

I probably should have said "no I can't help" but sometimes my desire to do what others can't (or just won't) gets the better of me, so I told him I'd have a go. The difficulty was compounded immensely by the fact that the bracelet is hard soldered to the case, so that couldn't come off, and the bezel clips into a groove cut into the case, which being a bit, shall we say 'agricultural' in execution means the tolerances were all over the place. It was never going to be easily to make something fit.

The first thing I did was fire up the lathe and turn up a test bezel out of aluminium, just to test the principle. It wasn't perfect. I did it a bit in a rush (time is money after all) and it came out of the chuck and got a bit mangled at least once. But it did sort of clip in tight enough to convince me it was doable.

The next piece of the puzzle was to go and talk to a jeweller who was able to make a 3D drawing of what I wanted and then print a wax model for me.  (Isn't modern technology a hell of a thing?) Actually he gave me two which is why I still had one to take photos of. I started this project long before I started the blog, so I never took photos of the process. It just spent a long time languishing in what I call my "too hard basket". But I digress. Actually, come to think of it, when I outlined my plan the jeweller raised an eyebrow at me and said he didn't think it would work....   It did.

Anyway, I then took that small piece of wax to Regal Castings up in Mount Eden and they turned it into a VERY EXPENSIVE exact copy cast in 18ct yellow gold. It was at this point that I got my first shock. It cost considerably more than I had calculated, but since I had now just forked over several hundred dollars for it, I was past the point of no return. If I wanted to avoid taking a complete bath on this project then I was going to have to complete it.... Even then it was never going to be profitable... Just educational.... which is why I'm now sitting here typing and trying to make some mileage out of it.

Ok, so I had a lump of gold in the basic shape of the bezel, (which sadly I never thought to photograph) but casting isn't very exact, and I had given generous measurements to make sure I could turn it down to suit. The next part of the process was to put it back in the lathe and make it fit the watch case.... and look nice. This involved turning up various jigs and holders out of alloy so that I could work on it without it flying out of the lathe and getting mangled like my alloy test piece. I started with a chunk of alloy bar stock and once I had done one operation I then modified it for the next operation. As a result I only have the final jig left to photograph for your edification.

I was having a lot of trouble getting the bezel to fit nicely into the groove in the case, let alone clip in place, due to the lack of accuracy in said groove. Around by the crown it was fitting nicely, but the other side wouldn't fit. I tried filing it, and then using a graver around the groove itself to open it up a bit, and eventually just went back to the lathe and turned a bit too much off the piece of the bezel designed to fit inside the groove. Great. It now sat down on the case absolutely beautifully.... It just didn't clip. What to do, what to do?

Hmmm, time to use some lateral thinking. I fitted a piece of stainless steel bar stock in a tool holder in the lathe, brought it in on an angle to the bezel and very carefully turned the bezel by hand so that the stainless acted as a burnisher and very slowly formed the bezel 'clip' so that it splayed outwards. Pretty much the opposite process of making a rubbed over setting to hold a stone in a ring. Mercifully it worked perfectly and I finally had something I could glue a glass into and clip onto the watch.

From my point of view it isn't perfect. If I had to do it again I would make it a little taller to allow a deeper seating for the glass, but really that's just a minor quibble.

I'm happy.
I hope the owner will be too.

Thursday, 15 November 2012

I Can Make Your Watch Look NEW!

A wee while ago a customer brought in her Omega watch. The glass was quite scratched, and it looked generally rather worse for wear, so we discussed fitting a new sapphire crystal. she liked that idea, and was even happier when I suggested I could re-groom the case to make it look like new again. I ordered a new factory glass and gasket, and she took her watch home to wear while we waited. The glass had to come from Switzerland, so there was a bit of a wait, but it arrived just the other morning, and she dropped the watch off later that same day.

I started stripping the case down before I got the idea to do a blog entry on it, so the photos pick up around the time I realized I needed to make a special tool to help disassemble the case. I could probably have cheated and mumbled something along the lines of "best I could do etc..." but this is a diamond set Omega with solid 18ct yellow gold bezel and tubes in the bracelet, so it had to be done right.

So the first photo I took is of making a tool to help me remove the bezel. Without doing this I would not be able to re-grain the case properly. Normally in the past I have found these bezels come out a little differently, but I think this was the first diamond-set version I've done, so it was a bit of a learning experience.... anyway, I used this little jig to reach the inside lip of the bezel and used a wooden mallet to lightly tap around the case, rotating it all the time. Bronte the apprentice was away sick, so not having three hands, I had to do the camera work myself... hence no action shots.

All that dirt is actually quite bad for your links. It causes significant wear in the stainless pins holding it all together and causes the bracelet to stretch. Regular ultrasonic cleaning (which we can do for you) is the best protection for your watch.

On the right here is the glass gasket. A nylon seal which the glass pushes into forming a very tight seal. Over time these crack under our strong UV conditions, and let in moisture. This one is going to be replaced.

So as you can see, the case is quite scratched, and quite dirty. This is entirely normal. We expect a lot from our watches. We wear them all the time in all sorts of conditions, and don't really notice how dirty they are getting until we see them post cleaning. The series of shots below show some of the cleaning process. I started with a new batch of cleaning solution in my ultrasonic tank so you can see the progression.
In the tank, but tank not turned on.

About 5 seconds after starting ultrasonic.

About 20 seconds after starting ultrasonic.

The ultrasonic tank is heated and when switched on, the transducers bonded to the bottom pulse at somewhere around 40-somthing kilohertz.  This causes cavitation in the liquid.... Microscopic air bubbles collapse and flash to high temperature. This removes deep down dirt and grease that we simply couldn't remove any other way.

Now that the watch is clean, it's time to do something about the scratches. This watch has a mix of 18ct gold which is relatively soft, and 316 stainless steel, which isn't. And the stainless pieces all have a satin grain on them, while the gold has a full gloss finish. This is one of the reasons I had to remove the bezel. I simply couldn't re-grain the stainless case properly with that soft gold in the way. The bracelet is somewhat different as you will see.

The first step is to polish everything to full gloss. On the stainless pieces, this usually takes two different grades of polish. One to remove the scratches, and one to restore a mirror finish. The gold is soft enough that I can skip straight to the mirror finish compound. So ironically, a solid gold case is cheaper and easier to do than a full stainless one.

One hand on the camera. I would never actually polish a piece one handed. There is quite a lot of technique in polishing things safely and accurately when your buff is spinning at 5,500 rpm.

The glossed case and my fingers all covered in polish.

It has been back into the ultrasonic, and now I'm brushing it to make sure it's totally clean. After this I use a high powered air gun to blow all the residual grit and moisture out of the links.

Then it goes on top of the espresso machine to dry. The top is heated to warm up the espresso cups, but it has been used to dry thousands of watch cases.... and make a lot of coffees.

Now for the really laborious bit. All the glossy bits have to be taped off with this special tape so I can restore the satin finish. This roll of tape is exactly the right width to cover one link and the gold tubes either side. After doing all these links, top bottom and sides, I pull off all the tape and do the alternate links. The taping has to be perfect. I don't want sloppy finishing.

I have various grades of satin finish buff.

Grooming completed. Time to unpack the factory sapphire glass. I think this might have been an upgrade to this watch, as the old glass was quite badly scratched, which sapphire shouldn't do. I actually demonstrate this in the shop by attacking the front of my watch with a file. The glass is harder than the file.

As a side not at this point, I can often offer an upgrade service to watches with scratched glasses. We can either fit a new mineral glass, or for a bit more cost is is often possible to fit a generic sapphire glass, which should retain it's appearance for years. It isn't always possible to do, but feel free to ask. In this case, because of the domed profile, and the particular thickness of the glass, and frankly, due to the value of the watch, we were always going to fit a factory original.

Anyway, at this point I realized none of the dies for my glass press were appropriate to re-fit the bezel, so it was back to the lathe and the milling machine with a piece of scrap aluminium to quickly whizz up a new die. You'll see why.

Bezel (and those darn lugs... not sure what else to call them) in place.....

......and fitted. I have a fair few specially made dies for various cases. It's one of the big advantages in having a workshop like mine. If I don't have the right tool for the job I just make one.

Change to the appropriate sized stock die to push in the glass......

....and done.

The movement is back in, and I've fitted a new battery just because...

And done!

No that isn't my wrist. At this point Bronte was back on deck and happy to model it for me.

So that's how we do it!

I think you will agree that all the work that went into this was well worth it. The customer was certainly chuffed with the result.

If your prized watch is looking a bit weathered, then bring it in, or snap a photo and email it to me for a free no obligation quote. There are few aspects of the job that bring me quite as much pleasure as giving you back a watch that not only works perfectly, but looks amazing too!


Wednesday, 8 August 2012

Bezel Changing.

I received a request for technical advice recently from a member of a watch enthusiast's web forum here in New Zealand, to which I occasionally contribute.

The watch in question is a Helson Buccaneer dive watch, which comes with two different bezels. The owner wanted to know how to safely remove one bezel to fit the other. I was feeling expansive at the time, so I suggested he send me the watch and I'd put together an instructional piece for the forum. You can find the forum post that also has some photos here:


To be honest, removing bezels can be a bit of a dark art, with some being relatively easy to remove, and others being virtually impossible, certainly without doing major case damage.
I recall needing to replace a cracked glass seal in a name brand dive watch a year or so ago, but being unable to remove the glass without first removing the bezel, as the outer edge of the glass was a couple of tenths of a millimeter larger diameter than the inner rim of the bezel. I eventually managed to remove it, change the glass seal and get it back together, but it was a major challenge and the bezel action was a bit rough after-wards. Talking to one of the watchmakers at the official service center a week or so later, he admitted that he was in the habit of putting the case in the lathe and removing a tiny bit of metal from the inner edge of the bezel so he could knock out the glass. He reckoned it did less damage.

Anyway, with some trepidation (my reputation was on the line after-all) I pulled the Helson out of the courier bag and had a look.
Oh good, it uses the same basic fitting system as TAG Heuer, with a stainless steel ratchet spring and a separate stainless wire retaining spring. I'm very familiar with this type, as I service a lot of TAGs that I've replaced quite a few of them. It should be fairly straight forward.

I had a quick look on Youtube to see what other videos there were on the topic, and decided there was room for one more, using correct tools and technique.


As per usual, for best definition, click the 'watch on youtube' tab.


Monday, 6 August 2012

Un-casing the Grande Classique.

The Grande Classique range from Longines has been in production for many years, and it's a very rare week that I don't get at least a few of them in for a battery change. Sometimes, though, a battery isn't going to make it go, and that is where things start to get a bit more interesting. Normally, it is a straight forward matter to extract a watch movement for service, but the Grande Classique's unique, tapered case presents a somewhat more interesting challenge.

Watch the video to see how I tackle this job.... and kids, don't try this at home. Done wrong, this will result in a shattered sapphire glass... and major expense to replace it.

Again, this is shot in HD, so it is probably best to click the "watch on Youtube" button to get the most out of it.


Sunday, 29 July 2012

Cutting some ratchet wheels.

Apprentice here. This is my first official post to the blog, and I thought I'd share with you one of my more interesting - yet minor - undertakings here in the workshop.

A while back a chiming mantle clock that was recently serviced came in for repair. It seemed the customers couldn't wind it properly. After dismantling it, the problem was obvious; two of the ratchet wheels were damaged. One had broken off two teeth, and the other had bent teeth. I apologise for my lack of photographs... back then I hadn't thought to document it further for a blog post.

There is so much spring tension on these wheels, it is not entirely uncommon for them to be damaged, especially when broken mainsprings are involved.

After a bit of horological mathematics, the right P.P Thornton gear cutter and stock brass was ordered for the job.

Example ratchet wheel pictured here, not the one from the job.
Once I had all the parts I needed, the brass was faced off in the lathe and prepared for cutting in the milling machine. Everything had to be aligned and centred correctly, and the Z and Y axes fixed into place.

If you've followed the earlier posts, you'll know about the Sherline rotary device (which unfortunately I couldn't recall the name of, and is henceforth referred to as the 'little computery thing') which was used in the milling of the Breitling case-back opener. I set this up to have twenty divisions/rotations, and got to work cutting the teeth.

Snip snip. It's hard to get a good angle on this one, but I'm sure you get the idea of what's going on.
Little computery thing did its divisions, and all I really had to do was crank the X-axis of the milling machine back and forth till my arm felt like it was going to fall off, or at least until the divisions were complete.

After that, the brass was put into the lathe, drilled, and with a noise most terrible, the two ratchet wheels were parted off.

After and before.
So here are my wheels next to the old, damaged ones... you can clearly see how they would have been causing problems in the clock!

All that was left to do was the filing, greasing and fitting, and hopefully that clock lived happily ever after. Time will tell.(Get it? Clock puns. I'm simply a comedic genius.)
(I'm sorry.)

Till next time. Hopefully I'll have something a little more interesting, and more photos to boot! Perhaps I'll bother to slightly further my horology humour, but my hopes aren't high for that dead horse.


Thursday, 26 July 2012

How did that happen?

Every now and then I get a watch in for repair and wonder how on earth it came to be in this particular state. In this case I received a year old Marathon automatic watch on my bench. Apparently it wasn't winding properly. "Hmm, ok, let's see.... oh, yes, I see what you mean. That doesn't feel good at all... right let's open her up and have a look inside." My train of thought went something like that.
So here's what i found once I pulled the automatic winding out to have a look at the manual wind component.

Can't see it?
Well it is pretty small. Have a really close look at the gold coloured wheel with the big screw head in the middle of it, just where it meets the steel wheel with the even bigger screw head. Still having trouble? Ok, let's use the microscope.

Ah, here we go. Four teeth completely gone, and the rest damaged.... So.....


Honestly, I have no idea. Customers ask me this sort of thing all the time. I point out damage to their watch, and they ask me how it happened. I don't know. But I do know how to fix it.

In this case, there was only one solution, and that was a full strip and clean of the watch, along with a replacement wheel.


Well you see, when a part comes off a wheel or lever or whatever, it tends to rattle around inside the watch until it can find the most amount of damage to do. I was kind of curious to see if I could find the missing teeth. I found two for sure. Here they are.

One stuck to the escape wheel.

And one (or maybe more) ground to dust under one of the reversing wheels in the auto winding system.

Once the strip and clean was done, it was all fairly simple. Put it on the regulator to check timing (which was bang on), case it up and water pressure test it.... Oh no wait, it wasn't quite, was it?

It is fairly common practice now for service centers to charge you for a new set of hands when they service your watch. Why?
Because they frequently get damaged during removal. In this case, the hour hand did not want to come off. It was so tight on it's wheel, that the hand started to peel off it's collet, bending itself in the process. In an ideal world, this collet would end above the level of the dial, so that any hand removal tool could grip under the collet, and pull it off cleanly. But this isn't an ideal world, and I could not get the tool under the collet. Rather, it pulled against the soft part of the hand and bent it. These hands hold vials of tritium gas which means they glow for 20 odd years without the need to collect any light first, so I had to be super careful not to damage them. Finding new ones could be very difficult. In the end I gave up trying to remove the hour hand, and just left it and it's wheel on the dial. Not ideal, but the best thing to do in the circumstances. I then had to line it up with the midnight date change when re-fitting it, and then straighten it, as the tip had ended up pointing up in the air. All this without doing any cosmetic damage to either hand or dial.

Well, it worked. This photo was taken after refitting.


All that remained was to test it and return it to it's happy owner, who asked me "It won't happen again will it?" To which I could only honestly reply "Dunno... I still don't know how it happened in the first place."

Thursday, 19 July 2012

Valjoux 7750 Automatic Chronograph.

Hey everyone.

Here is the first of what I hope will be many interesting videos on watch related topics. In this video I walk you through the basics of how the Valjoux 7750 chronograph functions. This was recorded, uploaded and blogged today, so you know it's fresh!

I have a bunch of ideas on stuff to video, but I'm open to suggestion. If here's something you'd like to know about how watches work, and I can video it, then let me know, and I'll see what I can do.

This was shot in H-D so if you click on the 'watch it on youtube' icon it shows up better. Full screen seems a bit grainy.