I thought I’d feature this example as it’s one of the lesser trumpeted Seamasters that Omega produced but just as good looking and collectable as it’s 300 & 600 stablemates, in fact with it’s slimmer case it’s more at home with a formal business suit in my opinion. This one arrived for a service and a new crystal along with a relume of the bezel pip.
The caseback is the screw down type with Omegas hippocampus logo featured in the centre.
The first issue as I removed the caseback was the gasket had reverted to a soft tar like sticky mess, the crown seal was the same.
Let’s have a closer look at that gunk. I’ve opened a few watches like this in the past and the residue is an absolute pig to clean up, you have to to remove the movement before you do anything else as it will stick to anything and everything! Once the movement’s out you’re then faced with the laborious process of picking the remains out of the case groove with pegwood and using solvent to clean up the residue. Yuck!
The movement is now out of the case in this shot, note a dollop of liquid gasket on the casing cushion, you have to be ever so careful not to get any on the dial 🙂
After some considerable effort the case components end up shiny bright again.
The watch is powered by Omegas calibre 601 movement, a manual wind 19,800bph beauty. The strip started with the dial side….
….and finished with the going train side.
Once everything was cleaned and inspected it was put away until the new parts arrived.
Once the parts were here the first job was to fit the new crystal.
A new crown was in order as the seal had been destroyed in the original.
The movement rebuild commenced with a new mainspring….
….and proceeded in an orderly fashion 🙂
The dial and handset were refitted…
….the movement was recased….
….and another one is completed! The serial dates this one to around 1968, it’s in cracking condition for a 48 year old 🙂
The Watch Bloke 
HI, what a great job done on this SM120,i have one in good condition but for some reason the spring below the bezel has frozen and locked the bezel,do you know if that spring/band is still available from any where?Mine is the same watch as this 1967 vintage.
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With the spring I’d just make a new one, however you’ll probably find it’s not the spring causing the problem it’s more likely to be dirt that’s locking things up. If you remove the bezel and clean everything, make sure the spring is flat then refit it all again should be OK.
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Hello
I have a 120 from the 60s and it was cleaned and servised by a professional in San Diego. But it leaks water in the shower. What is your guess?
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The problem with re-sealing things like pushers and crowns on vintage watches is that some crowns can’t be serviced so they have to be replaced and some pushers can break when trying to remove them, especially types where there’s a screw retaining it. This of course would mean locating new or replacement parts for a vintage watch and a lot of the time they are impossible to find. Sometimes it’s better to leave well alone and not service the pusher seals rather than risk breakages, but it does mean you should be made aware not to get the watch wet. I must say to shower whilst wearing a vintage chronograph is madness in my book, it’s just waiting for the inevitable to happen.
I’ll say what I say to every owner of a vintage watch (including vintage dive watches) and that’s don’t submerge them, it’s just not worth the risk. Even if it’s been resealed and passed a pressure test all it takes is a bang on the crown or case that you don’t remember doing and that could be enough to compromise any water resistance it had, the first thing you’d know about it is when the watch fills up with water. Bad enough with a new watch where parts are readily available but lunacy with a vintage piece!
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