Before Eterna became famous for their Eterna Matic movements they had a very nice bumper movement. This is my first bumper automatic and I’m exited to see how it works.Movement is in excellent condition for a watch this age.No doubt that a service is needed.I start by removing the automatic bridge so that I can remove the pivoting weight.Here you can see the springs that absorb the shock of the pivoting weight.Here you can see the ratchet lever (gold part)) that transferee the power from the pivoting weight to the ratchet wheel.The underside of the ratchet lever.The movement ready to be taken out of its case. Note the early shock protection that Eterna used.The movement out of the case and I remove the cock that holds the sweep second arbor in place.The dial side of the base plate you can see the setting mechanism and the other shock protection device.The varnish has faded and tuned yellow brown. The original luminous compound is still on the dial and great care must be taken when cleaning.I take a risk and give the dial a mild clean and varnish for protection.And the risk pays of!I remove the balance and with these old shock devices I need to remove the complete balance to be able to oil when assembling the watch.Old mainspring.Here you can see the gear train.Here are all the parts after having been cleaned.Upper and lower shock device.Testing that the balance moves freely.I have souced a NOS mainspring that I useMovement coming back together nicelyBase movement almost back togetherDial side of the movement before putting the dial onAfter a closer inspection I see that one of the hands has gotten new luminous compound at one point.As the lettering on the dial has aged patina I decided to experiment with tea to get a darker colour on the luminous compound. I start of by mixing the luminous compound in tea.It is important to wait until the compound is completely dry before mixing it with binder.The compound applied to the hands.Dial and hands back on the movement and I feel I hit the colour pretty well. Note I love that Eterna has a red marker on the second hand. Feels a little sportyMovement back in the case.Performance is goodI think this watch looks very good.If anyone is wondering the compound still lights up after the tea treatment.The 34mm case makes this 40’s classic very nice to wear;)
Sorry for taking up this old post. I recently acquired a watch with a closely related movement myself and have now got a question about the shock devices. Your post shows that it is possible to remove those for cleaning. Now I wonder why it was necessary to remove the balance spring from the cock for oiling. Can you help me?
Thank you and kind regards
Frank
On non-shock protected movements, you have to remove the balance and take the cap jewel off for cleaning and lubricating. On movements with a shock device, that isn’t necessary.
Thank you!
Kind regards
Frank
Hi, Lovely job.
I have one of these but the movement is loose in the case. I think this is because the piece of metal that is screwed to the back of the movement (and which presumably pushes against the watch back) is missing.
Do you what this part is called?
Kind Regards,
Matt
Hi,
I’m not quite sure what it’s called, but I would probably define it as a case clamp.
What did you use to re-varnish? I once tried nitrocellulose (Zaponlack” in German) which dissolved all the printing. Another near-death in amateur hands.
We use water based varnish.
Great job on the movement and an excellent restoration of the hands and dial. It has an interesting anti-shock system with the jewel and its carrier sliding in a slot whenever there is a jolt. I’ve never seen that type before. Thanks for posting.
Another cool Eterna!
Great job. Especially impressed with the hands reluming. Very nice color match.
Thanks Anders! Definitely a cool Eterna:)
Most Eternas are! I especially like the crown on this one…
Nice patina on the dial! And an even beautiful bumper movement.
Thanks Vardhan:)