Rotary Aquaplunge Service: Calibre AS 1700

Vintage Rotary watches are always of a higher quality than their modern counterparts and some can be quite collectable. The super cool looking aquaplunge is an example of these a robust automatic movement in a rugged case with a clean, easy-to-read dial and a date complication all in a very wearable 36mm package. What’s not to love? We recently had one come through the workshop which needed a little care so let’s dive right in.

Rotary Aquaplunge Before Service and Restoration

From the outside there’s nothing too serious to see. The general wear and tear you’d normally expect, plus all the dirt from being worn. The lume on the dial is quite stained - this can be a result of moisture ingress so it’s good to keep an eye out for other signs in the movement.

Fluff or dust wrapped around a watch escape wheel

If I had a dime for every time I saw this….
It’s amazingly common, even with watches that are supposedly sealed with o-rings like the aquaplunge, to find giant pieces of fluff in the train. Clearly this thread wrapped around the escape wheel wasn’t helping the watch keep good time. As part of a service the entire watch is dismanlted then every individual component assessed in detail to ensure all problems (obvious or not) are spotted and addressed.

The unusual automatic winding mechanism on an AS 1700
The barrel and arbor of an AS 1700

The connection of the automatic work to the barrel is somewhat unusual in the AS 1700. The photo on the left shows two reduction wheels, one of which has a spring loaded ratchet mechanism that works on a matching feature on the barrel arbor. The spring loading allows the barel arbor to move without forcing the auto wind wheels round and thus the watch can be wound manually without ‘windmilling’ It’s worth pointing out the dark ring on the barrel - it’s not dirt, but is staining or discolouration as a result of a pool of oil on the surface.

AS 1700 Dial Side serviced by Harris Horology
AS 1700 Movement without Automatic Mechanism

Aside from the usual automatic coupling mechanism the AS 1700 is a fairly standard late 20th century movement. This is a fairly high-end example with shock protection and an endstone on the lower escape wheel pivot. The endstone helps reduce friction and thus improve timekeeping and reliability.

Rotary Aquaplunge with new SuperLumiNova applied and glowing

The client requested a restoration of the dial Lume, as the old stuff was dirty, damaged, and hadn’t glowed for a LONG time. I use a special colour of SuperLumiNova from RC Tritech in order to emulate the colour that old lume would be if it were allowed to age gracefully; a warm parchment hue. It’s also the highest grade available meaning the glow brightness and duration is comparable or better than any modern watch, giving the hands and dial a visibility better than it’s ever been in low light conditions.

Lume was commonly applied by hand on 20th century watches and so is rarely perfect. The application isn’t always ‘inside the lines’ but this adds to the charm of these dials. When I am applying new lume I am always very careful to leave witness marks from the edge of the original compound: this allows me to replicate the original shapes exactly and so keep the character intact.

Rotary Aquaplung Serviced and Restored at Harris Horolgy