Service: Omega Seamaster calibre 352

IMG_7712Another day, another bumper 😉 This one travelled all the way from Norway, and Anders sent it over.

The luminous dots on the dial are missing, and he would like those restored, the movement needs a service, and a new crown…



Upon opening the case, I notice that someone has put lead into the groove where the gasket goes. Very strange, and I can’t make any sense of that (yet)…


On top of that, there is a hard plastic gasket which looks a bit home grown. The bells don’t ring yet, maybe you know already what’s going on!IMG_7719

I carefully clean out the lead from the case.IMG_7720

On the bottom plate, the set lever spring is broken and needs replacing.IMG_7729

The gear train is visible with the train bridge removed.IMG_7733

The mainspring is of the old type, and I will put in a stainless steel mainspring.IMG_7734

All ready for the cleaning machine.IMG_7822

The new mainspring is ready to be put into the barrel. I got a batch of 5 NOS, and I only have one left…IMG_7823

The balance jewels go back in, and the cap jewel gets a tiny drop of oil.IMG_7824 IMG_7826

The basic movement is back together and ticking.IMG_7829

All looking nice and tidy. There is a tiny bit of oxidisation marks on the click wheel, but that’s to be expected on a movement that age.IMG_7831

The new set lever spring looks nice.IMG_7850

David Bill and Sons has done another great job on the luminous dots.IMG_7854

I case the movement, and make the final adjustment.IMG_7855

Back together, and I notice that the oscillating weight hits against the case back. Now I know why the lead and plastic gasket were in the back!IMG_7857

The old crown and winding stem need replacing – the old one is still in place in this photo.


Anders provided the new part, that he found in France. IMG_7913

With the new crown and winding stem, I test if the watch is water resistant. The result is “a bit”, which is normal for a vintage watch. The gasket surfaces are always a bit pitted and worn, so even with new gaskets, the watches are never completely water resistant.IMG_7914

Back together and looking beautiful.IMG_7922That looks great, too!


14 thoughts on “Service: Omega Seamaster calibre 352

  1. Watch arrived today. Thanks again Christian! I am very pleased with the end result. It looks better than I ever hoped, Timegrapher confirms the sweet running 352 has not suffered on its way across the North Sea. Fitted it on a new “vintage style” brown ostrich strap this evening, so now it’s ready for some gentle wrist time:-)
    Kind regards from Norway!

  2. The regulator is whats known as an RG regulator, quite rare and sought after by Omega collectors, I have a rare pre production Seamaster with the 352 movement, a very rare watch but all 352s are are rare.

    • Ah – you live and learn!

      The good thing about the regulator is that it’s easy to adjust very finely, and the bad thing is that even the slightest pressure on the regulating screw puts pressure on the balance cock, which throws the whole balance out of whack, and you have to wait ages until things are back to normal. It’s a screw, so you need some pressure, and it’s a bit of a fiddle.

      A normal swan neck doesn’t put any pressure on the balance cock as the screwdriver is inserted laterally, regulates just as finely, and, in my opinion, is thus superior. Also, it looks pretty classy 😉

      So my vote goes to the swan neck.

      • Hi Christian,

        I agree,

        From memory and I could be mistaken,
        352s are rare because Omega did not make many back in the 1950s, the production run was limited.

        prices for a parts movement is around £ 200-300.00 and a good working watch from around £700.00, price being a subject of some discussion perhaps, but a good example is easily over £1000.00 but it must have the right look about it.

        Solid gold or Gold on Steel are the most desirable, you can sometimes see a steel watch case with heavy gold layering on parts of the case, notably the lugs, the crystal retaining ring is usually made from solid 18k gold, screw down case back is in steel unless its a solid gold watch.

        kind regards,


        • Hi!
          The 352RG was listed at the time as a deLuxe movement by Omega.
          It was used in the very first series of Omega Constellations (confirmed in the official book “Omega Saga”) in addition to the top grade Seamaster Chronometers.
          The 352 inherited the RG (fine regulation) from the famous 30T2RG hand wound movements.
          Omega Seamaster Automatic Chronometers from the early years will more often have the 354 movement. The 354 chronometer has the swan neck regulation, whereas the 352 has the RG (also known as the “Omega System”).
          There are many discussions on the subject if the RG regulation is better or not compared to the swan neck. At the end of the day I think it looks fantastic, and it is definitely the rarest of the two.
          How many 352 RG movements that was produced is not documented (as far as I have found), but there are not many around. The production only covers the years 1949 to about 1952.

          Kind regards,

  3. Hi Christian,
    It has been a true joy to follow the process of bringing this little old gem back to life. Your way of working has been perfect for such a task. The chance for me to follow the steps, and make alterations (and supply spares:-), as it progressed was really great.
    The Omega Seamaster 352 RG now looks as good as I had ever hoped for.
    It will be worn gently and with great pride!
    How was the process of regulating the watch? I have not attempted this myself on a watch with the RG / fine regulating.

    Kind regards,
    Anders / Norway

    • The movement is pretty straightforward to regulate – the fine regulator works well, you just have to make sure you don’t apply any pressure to the screwdriver.
      I’m glad you enjoyed watching the process on the blog. I have shipped the watch today, so it should be with you in a week or two.



  4. “Upon opening the case, I notice that someone has put lead into the groove where the gasket goes. Very strange, and I can’t make any sense of that (yet)…”

    I have to say that I’ve come across quite a few screwback cases with lead ‘gaskets.’ I’m not sure when they were popular, but I’ve bought a few 1960s era watches with lead. It’s a bit tricky to dig it out, but a great sense of relief at getting rid of something that probably shouldn’t have been used.

    Anders’ Omega looking very nice in the end!

    • My guess here is that the lead was put in to make the case back stand out further, so that the oscillating weight wouldn’t hit the case back. Lead was used by some repairers instead of rubber gaskets as you don’t have to keep different sizes in stock.

      • Lead gaskets were pretty common on aircraft instruments up until the 50s… I wonder if many military instrument technicians retrained as watchmakers and took the technique with them, or if perhaps it was the other way around.

        Omega certainly knew how to make a good looking watch back then 😉

        • That makes perfect sense – you stick to what you are familiar with and what works, and the health implications of handling lead weren’t really known back then!

          • Lead provides a very effective water tight joint if used correctly. I’ve seen lead washers on the roof of old industrial buildings, and lead was used extensively in water supply services; think of solder-ring copper pipe fittings, although lead is no longer used in the solder.

            Can’t imagine you would want to heat up a watch case with a flame however :-O

        • A lot of info on the lead gasket but I will add my version also:) I had a led gasket in my old Alpina cal 598 and my school teacher (Danish watchmaking school) says it is probably from the factory when rubber gaskets still where a new thing. It has some protection against water but will corrode and expand the case shut (what has happened to one of my watches) and most watchmakers have replaced the original lead with rubber at one point, so the watch has either not had a service in LOOOONG time or someone has ignored changing the gasket every time!…

          • I’ll revive this conversation from years ago and add my two cents. Going through a box of old miscellaneous watch parts what would I find but a new-old stock Omega lead gasket. Wondering what the heck this thing is I asked the internet and wouldn’t you know I land on one of my favorite blogs. ^^

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