So, a few months ago Christian very kindly offered to open his blog up to his fans, and i’ve decided to take him up on this offer! My name is Sean and I live in the North West of England. I’m an electrical engineer by trade, but have spent the last 6 months indulging myself in the world of watch repair and renovation, and have begun to reach the point where I repair more watches than I destroy!
Over this period, I have learn’t much of what I know from 2 things. Firstly from my own costly mistakes (usually where the best lessons are learned!), and secondly from the wealth of information available online, and in the second instance, nowhere more than Christians blog. I hope that by adding a few of my own projects, I can pass on some of the things i’ve learned along the way.
The first project i’d like to show everyone is a rather fine pocket watch I serviced for a colleague. It’s a swiss made Cortébert movement in a Dennison gold-filled Half-Hunter case. I’ve dated it vaguely at about 1930’s to 1940’s, and the movement is somewhere between a Cal. 526 through to a Cal. 548, but a highly decorated version. It needs a service and the dial needs cleaning up due to what appears to be a glue mark. Here we go…
You can already see lots off dirt, most of which appears to be dried oil. If you look carefully you can see a missing screw on the bridge. One of the remaining 2 screws on this bridge is actually a ‘blued’ steel screw, whilst all the rest are stainless, so I guess whoever serviced it last lost 2 screws and only had one other that would fit! Seems solid with just the two though, and I don’t have anything that will fit, so it may have to stay that way.
Movement removed from case, this involves popping off the glass & bezel from the front, removing the 2 case screws, and then ensuring the crown is in the pulled out ‘hand set’ position. This is important, otherwise you can snap the stem when removing the movement through the front.
The case is now ready for a clean in the ultrasonic bath, and a gentle polish.
Dial ready for cleaning, the dried glue is visible at the 7. Thankfully it’s an enamel dial, so it’s not too delicate, and I can scrape this off with a piece of peg wood.
Less decoration on the dial side. Lot’s of dried oil though.
I begin disassembly, after letting the main spring down, I remove the click spring etc.
The wheel bridge is off.
The quantity of dried oil is clearly visible, it seems to have migrated everywhere!
Quite strange pallet’s, I’m presuming they are clear because they’re sapphire crystal rather than ruby, but maybe they’re diamond?!
We’re all back together, oiled and cased, and now the hands are set. I check for clearance between the hour and minute hand. I rather enjoy this bit!
Looking nice and clean.
At this point, I test it’s timekeeping and discover she is running about 8 minutes a day fast. Although it’s an old watch, this is still a little too much so I investigate further. The eagle eyed amongst you may spot the issue in the picture. The hairspring is not sitting centrally around the balance shaft, causing 2 coils to touch. This shortens its relative length, and makes it run fast. Firstly I purchase a de-magnetiser and try this, but it doesn’t solve the issue. (Useful tool though!) Next, I take the balance out and see that I have straightened the ‘dog-leg’ in the spring whilst reassembling the balance assembly after oiling. 🙁
At this point I have to make some tools for manipulating the hairspring. I do this by cutting the tops off the heads of 2 needles. This leaves me with 2 tiny forks with which I can GENTLY bend the spring back into shape. I can’t express how stressful a job it is!
After a few lucky slips, it’s as good as I feel i’m going to get it. I put her back together and find she’s about 20-30 seconds fast, laying face up all day, and i’m happy with that!
I begin to fit the glass. and then disaster strikes…..I underestimate how delicate the glass is and crack it 🙁
£30 later and i have a NOS glass fitted and can return the watch to its’s owner.
Which lasts about 30 minutes before I get a text to say his son has put his thumb through it! After some discussion, we decide to opt for an acrylic crystal this time, since they are a fraction of the price and less delicate.
If we don’t like it, we haven’t wasted too much money.
New crystal fitted, she looks fine, and after moving around all day (traveling to and from work a few times!) she seems to have settled at about 1-2 minutes fast a day. I decide that’s good enough for me until I purchase a timegrapher, and will also try and replace the 2 missing stainless screws if I ever come across any in the future.
So, important lessons learned:
1. Beware delicate hairsprings! They are incredibly easy to ruin, and are obviously very important when it comes to decent timekeeping. I hope to not make this mistake again, as manipulating hairsprings takes years off your life!
2. Beware delicate glass! Obviously you have to be careful with all parts of a watch, as there is very little that is not delicate, but Hunter pocket watch glass is the worst i’ve experienced with ‘crystals’. However the modern acrylic replacements, although not in keeping with maintaining originality of the watch, are certainly more durable and you really can’t tell the difference.
Thanks for reading, and I hope to be able to add some more articles to Christians blog in the future.