Wristwatch restoration, servicing and repair

Heuer Monnin (FE Cal. 4611A)…

An iconic diver to kick off the New Year, a Heuer Monnin.

(Click pictures to enlarge)

The Monnin is something of an enigma in the Heuer back catalogue, as the time-line of its production history hasn’t been fully determined.

What is known is that in the mid-late 1970’s Heuer were being approached regularly by diving enthusiasts asking why there was no Heuer diver? Recognising a potential gap in the market, Heuer approached the French manufacturer G. Monnin to re-brand one their existing diver’s watches so they could test the market. Monnin agreed as they were already doing the same for other manufacturers (you’ll see almost identical watches from other brands such as Alfex, Bessa and Le Cheminant) which suited Heuer perfectly as it gave them an entry into the diver arena without the pre-production cost of tooling.

To say the watch was a success is an understatement. At a time when Heuer was struggling to stay afloat during the quartz revolution, the sales of the Monnin saved the company. To quote Jack Heuer from a recent interview “…and would you believe it, these watches started selling like crazy. The company came out of trouble because of these watches. You know, Bo Derek wore one; we have it now in the museum”.

The earliest printed record of the Monnin is this Heuer catalogue from 1979 which featured the watch on the cover.

(Picture: OnTheDash)

Much of the confusion around the Monnin exists because the dial, hand and bezel insert designs were changed during the brief production cycle, resulting in a variety of combinations being used in the watches sold.

Comparing the watch in this post to the picture above it has all the hallmarks of an early model. A ‘cathedral’ hour hand, the early style bezel insert and the ‘professionel’ text is in lower case letters on the dial.

Curiously, the subject of this post also has a second hand with a large lume ‘lollipop’ whereas most of the automatic Monnins have a much smaller one like in the picture above. The owner says that this second hand has been fitted since new – he had the watch bought for him as an 18th birthday present by his father in the late 1970’s (from Harrods no less!).

For comparison, here is a picture of a later model with the Rolex Submariner style bezel insert, a ‘Mercedes’ hour hand and a dial with capitalised text and “Made in France” printed at the bottom.

(Picture: Heuerville)

The watch in this post received regular maintenance throughout its life, but due to the caseback not being fully screwed down after a movement service, the watch suffered an ingress of sea water during a dive several years ago. On returning to the surface the owner immediately unscrewed the caseback by hand and rinsed the watch out with fresh water in an attempt to minimise the damage.

Fast forward to the current day and after hearing the story I was still expecting to see a significant amount of rust. With the caseback removed, some rust was evident but I was expecting it to be worse.

The calibre in this watch is the French Ebauche (FE) cal. 4611A. A Swiss mid-level 17 jewel automatic with a beat rate of 21,000 bph. This calibre was only used in the Monnin as the calibre was replaced by the ETA cal. 2872 when production moved to Switzerland and the watch became an ‘official’ Heuer model, the 844.

With the automatic winding mechanism removed, the signs of rust were increasing; several of the screwheads were rusty and the balance cock / regulator showed signs of corrosion. Seeing this, I was already concerned about the condition of the pivots on the train wheels and other delicate steel parts…

Sure enough, with the train bridge removed I could see that all the train wheel pivots were corroded, along with the balance staff pivots, the mainspring, the barrel arbor, and several parts in the automatic winding mechanism. Here are some of the parts that we beyond salvation.

Thankfully, parts for the FE 4611A are still available, so the majority could be replaced without a lengthy search this time. Some effort was still required to remove rust from other parts, but the movement could then be cleaned and rebuilt.

From a cosmetic perspective the lume on the dial and hands were largely unaffected by the salt water, but the dial did have some staining where water had dried on the surface.

Deciding what to do in these situations is never easy as attempting to remove any staining can make it worse, or damage the dial print or paint. After consulting the owner we decided to re-wet the stain and try to remove it. As the dial dried I was pleased to see that the staining was disappearing before my eyes… phew!

With the movement back up and running, the case was cleaned and the watch rebuilt. Finally a new caseback gasket was fitted… and the caseback secured properly this time.

Rich.

** Many thanks to Nigel Glen for letting me feature his watch on the blog. **


Comments are closed.