Old Doxa wristwatch and a tale of woe ... and webs

[GPrideaux]

I'm working on a mid-1950s Doxa wristwatch for a friend. I'll call him John, since that's his name. It was his father's and hasn't been working for some time. He told me he took it to "one of those places" and they "really messed it up."

The first challenge came before even opening the case. The spring bars fitted were of the type that need to be pushed in from the ends, and of course the lugs don't have through holes. Looking at the bracelet, it's clear that it had been fitted by bending it around the spring bar. Initially I just scratched my head, then proceeded with the bracelet on the case. Since then I have managed to cut the old spring bars out and will replace them with the proper type.

Here's my first view of the movement:

A bit scratched up, especially around the setting lever screw, but not too bad. No shock protection. I hope the beat error isn't too bad because where the hairspring joins the cock isn't adjustable. I haven't yet adjusted beat error by turning the collet and I don't want to do that for the first time on a watch that matters to someone. The case screw on the left of the picture only has half a screw head, which might have been a tale of woe, but as it happens the screw was loose and came out easily. It will be replaced. (I actually lost the intact screw while measuring it ... it pinged away out of my tweezers, but only after I had the measurements I needed, so I should be able to replace both.)

The crystal and bezel had to come off as the movement comes out of the front of the case. The crystal is in pretty good condition. The dial is rather beaten-up, but I won't be attempting anything more adventurous than a gentle clean of the indices. The finish is coming away a little around the edge, esp. between 6 and 7, and I'm concerned that even a gentle wash with distilled water is likely to accelerate the damage.

My first view of the dial side of the movement shows that it's an Eta ebauche. When I remove the balance I can see that it's Cal. 1147. My research tells me this is a variant of the Eta 1080: larger mainplate; no shock settings.

Wait, is that oil EVERYWHERE? Yes, yes it is. Also notice the setting lever spring ... or lack thereof. It's broken, but where is it? Initially I thought that it must have been broken when it was last 'serviced' and the broken spring arm taken out then, but I later found it. It had been stuck to the back of the dial with oil.

When removing one of the tiny screws holding the minute wheel cover plate, one of them decided that half a head was enough ... it was super tight and when I was trying to coax it out half the head broke off. The rest of the screw then came out easily. Oh well, I need a donor movement for the setting lever spring so it can donate a screw as well.

I proceeded to full disassembly which has no more surprises, unless you count that the click screw doubles as a barrel bridge screw. It's a direct drive sweep seconds movement: the fourth wheel has an extended pivot and is concentric with the centre wheel, with the latter sitting under its own bridge.

Here are the third wheel, fourth wheel and escape wheel sitting in the parts tray. Note the extended pivot on the fourth wheel.

Next everything gets cleaned. To do this I first peg the jewels then I put all the smaller parts into small cleaning baskets, and these go with the bridges and larger parts into a cleaning jar and into the ultrasonic for a wash and two rinses ... everything except the balance complete and the pallet which I clean separately in hexane. I clean the cap jewels in the hexane, too. Again, no major surprises and I'm feeling pretty confident I can improve things for this watch. It can't really be much worse ... look at how much oil the parts left behind in my parts tray!

The barrel looks a bit beaten-up inside. I may replace it if the donor movement has one that looks better. But all the teeth seem to be fine, as does everything else.

Well, a donor movement ordered, and I clean the pivots with pithwood and start reassembly and lubrication. All goes well ... no springs lost. I put back the broken setting lever spring as it serves as a cover for the yoke and yoke spring, wind it and check that it's working nicely, then put it away to wait for the donor movement to arrive.

Fast forward three weeks. The donor movement is here; time to finish this watch and get it back to its owner.

Remove setting lever spring from donor, clean it, then swap it into John's watch with a spot of grease where it interfaces with the setting lever. The donor has one screw missing from the minute wheel cover, but I take the other screw to replace the broken one. Let's case it up!

That's funny, what are these webs on the case? There's some on the bracelet, too. And in the dial box. And in the membrane box holding the hands. All the parts that had been sealed up in a zip-seal plastic bag. There's clearly been something alive in there ... no idea what or where it came from. I clean off what I can manually and put everything except the dial into the ultrasonic at 60C. Hopefully that should kill anything that might still be there. I had already cleaned these parts once, but the stretchy metal bracelet was clearly still hoarding some dirt as the water is really grubby afterwards.

Anyway, doing my best to ensure there was nothing alive on the dial I start putting the watch together. Dial on and dial screws secured. Hour hand on, making sure it clears the indices. Minute hand on, making sure it clears the hour hand. The watch is running beautifully as I put the seconds hand into place. That's funny, why isn't it moving. Oh, it's still loose. Did I miss the pivot? Lifting off the seconds hand and I can't see the end of the extended fourth wheel pivot. It's with a sinking feeling that I check the photo: yes it was definitely visible when I first took the watch apart, but it is definitely not visible now. Off come the hands. Off comes the dial. Out with the balance and the pallet after first letting the wind down. Take off the train bridge and the ratchet wheel and take out the fourth wheel to find ...

... somehow I have managed to break the extended pivot. I don't know when or how, but it was intact and now it isn't. There's no sign of the broken tip. My best guess is that the pivot worked its way through the mesh of the cleaning basket and broke off as the basket was rolling around in the ultrasonic or as I was removing the parts after cleaning. And I just didn't notice.

You're probably thinking, no big deal, just use the part from the donor movement. Most of the donor movement was alright, but there was a little rust in places, and nowhere more than the inside of the centre wheel tube. The centre wheel and fourth wheels are unusable. In fact, as I was trying to coax the fourth wheel out, the wheel came off the arbor. Maybe if I was a real watchmaker and not just an inexperienced amateur hack I'd be able to fix that. When I get a staking set I will probably be able to reattach the wheel to its arbor but I very much doubt I'd be able to clean the rust off the pivot well enough to use it, even if it isn't deeply pitted (which it may be ... I haven't checked). So, I now need either a replacement fourth wheel, either new or from another donor movement. (And probably another three week wait for them to be delivered. That's just part of living in one of the most isolated capital cities in the world.)

I wish I knew how I broke it so I can avoid making the same mistake again. Any words of wisdom from the gurus here would be welcome! Also, that web! If you have any thoughts about that, let me have 'em! The only time I've seen anything like that before was when we had some pantry moths infest a packet of oats, but there at least the critters were visible. Here all I see is the web.

Glen

Edited October 12, 2024 by GPrideaux

[mbwatch]

Did you clean in those brass baskets that screw 2 halves together? I am very concerned about long pivots in those and have stopped enclosing 4th wheels.

[GPrideaux]

Yes, in an inexpensive screw-together brass basket. I think the mesh is coarse enough that the pivot could have gone through it. I'll keep long pivots away from it in future, as you suggest.