Wristwatch restoration, servicing and repair

Nivada Grenchen Chronomaster (Valjoux Cal. 23)…

This Chronomaster Aviator Sea Diver from Nivada Grenchen arrived in pretty much the same condition as the last one (that post here).

(Click pictures to enlarge)

The Chronomaster was first introduced in 1963 and remained in the Nivada lineup until 1978. During that time it changed significantly both in terms of styling and the calibres used inside. The main changes being that the broad arrow hands were eventually replaced by baton style hands, and the column wheel chronograph calibres were replaced by cam-lever chronograph calibres which were significantly cheaper to produce.  (For a detailed history of the Chronomaster check out this excellent post on the website Inventit Et Fecit).

I bought this watch as a restoration project based on a few pictures and an email discussion with the seller. Overall the condition looked to be relatively good, but the calibre inside remained a mystery until the watch arrived. While there is no such thing as a ‘bad’ Chronomaster (in my opinion!), I knew based on the style of dial and hands that this watch was one of the earlier models which gave me hope that one of the better column wheel chronograph calibres would be inside.

Opening the caseback I was pleased to see a Valjoux cal. 23, still in excellent condition and with no sign of abuse or corrosion… always a bonus.

In terms of the cosmetic condition, things looked good too. The case had a few marks, but no major dents, and the bezel insert was still in decent condition which is not always the case on these watches. I’ve yet to see a Chronomaster with a perfect original bezel insert as the bezel insert sits slightly above the level of the bezel it is subject to wear, especially on the outer edge.

The dial was still in near perfect condition, the lume on the hour markers had darkened but was still intact. The lume in the hands was well past its sell by date and had deteriorated to the point of falling out.  You may have noticed in the first picture that the hand for the minute register was missing. When a hand is floating around the dial there is always a chance that the tip of an axle has been broken off, but thankfully that wasn’t the case here, the hand was just loose.

While the watch did run and the chronograph was working, looking at the condition of the oil under the microscope I could see that it had completely dried out, a sure sign that the movement hadn’t been serviced for quite some time. A full service followed and the movement was looking good again.

All that was left to do was to tidy up the cosmetic issues. The hands were relumed, the case cleaned and the crystal polished, here is the result.

To finish off this post, here is a 1960’s advertisement I found for the Chronomaster… a watch for all time.


One Response to “Nivada Grenchen Chronomaster (Valjoux Cal. 23)…”

  1. Douglas Ott Says:

    Nice article and resto. I just recieved a chronomaster from some auction near “the bay” and it arrived from Hong Kong looking pretty good. Has the (lesser :+) Landeron 210 movement, but dial is exc. broad arrow hands are original and show corrosion under mag. but look fine. I’ll try and forward the photos. Got mine with the original Croton box and dial reads Croton & below Nivada Grenchen. Lume and hands have mellowed to a brown mustard tone. Bezel insert is very clean and it’s a keeper now if my chonograph would just start and stop Ugh!!!. Seems that there are many small dial variations but the watches are always similar. Too bad they couldn’t go auto to survive the Quartz boom. Saw Nivada display in Mexico Airport still alive in S. America. but were mostly quartz models boooooo….