Wristwatch restoration, servicing and repair

Heuer Chronograph Ref. 3641 (Valjoux Cal. 92)…

An early candidate for this year’s “ugly duckling” award was this Heuer ref. 3641 which had obviously seen its fair share of action…

(Click pictures to enlarge)

The Heuer ref. 3641 was first produced in the early 1960’s and pre-dates the similarly styled Carrera models. When Heuer introduced the Carrera models in 1963 they also designated some of the existing models as their “economy line”. The main differences being that the Carrera models were all housed in solid stainless steel rather than plated cases and some were fitted with the higher quality, 3 register, Valjoux cal. 72 – the benefits of a solid stainless steel case are evident from the condition of the watch in this post, with extended use and exposure to the elements the plating eventually wears away exposing the base-metal case underneath.

The ref. 3641 underwent a number of design changes during its production run as shown in the comparison picture below. The early models had dauphine hands and the case had small diameter pushers whereas the hands were changed to baton hands and larger diameter pushers were fitted to the later models.

(Picture: OnTheDash)

As evidenced by the picture above the watch in this post is one of the earlier models and was probably made around 1964-65. The dial on this watch is different to all the others I’ve seen however as the minute track print is slightly different and the dial has shorter applied batons for all but the 6 and 12 hour markers.

The owner of this watch had initially approached Tag Heuer to restore the watch but they refused due to a lack of available parts so I was asked if I would consider taking it on. On one hand I can see why they refused – when a watch is presented in this kind of cosmetic condition, you never know what you’re going to find inside.

Thankfully in this case the movement, a Valjoux Cal. 92, wasn’t nearly as bad as I’d expected. The loss of plating was even more obvious on the rear of the watch case but once inside, aside from a little tarnish on a few of the parts the movement was in decent shape. The watch was still ticking, albeit weakly and the chronograph functions were all working, but the oils had all dried to dust so the movement was long overdue a service.

Out of the case the condition of the dial and hands was a concern. You can see in the first picture that the acrylic crystal had a number of cracks around the edge which had let water seep into the case over time, damaging the minute track on the outer edge of the dial and degrading the lume throughout. Curiously, the lume in the hands was two different colours which suggests that one of them must have been re-lumed or replaced at some time in the past.

One option would have been to send the dial out for refinishing i.e. stripping back to bare metal and re-printing, but I’m not a fan of that process as it’s rarely possible to replicate the original dial layout and fonts exactly. It also removes the history of the watch and often decreases its value so refinishing will remain a last resort for me.

Removing the debris and as many marks as possible was the chosen course of action this time as well as re-luming the hour markers and hands with a vintage cream lume. Given the starting point the result was never going to be perfect but I think it was the right thing to do in this case. (You can judge for yourself in the pictures below!)

As you have already seen the case was in very poor condition so while the service and cosmetic work was under way I placed a ‘Want To Buy’ ad for a replacement case on the OnTheDash forum – it was a long shot but worth a try. The Heuer community came through for me once again and within 24 hours an enthusiast in Italy had offered a complete early 3641 case in near perfect condition. Payment and postage was swiftly arranged and the case was soon en-route.

With the movement serviced and the cosmetic work complete, the watch was ready to be rebuilt as soon as the case arrived. Here’s the result.

Rich.

** Many thanks to Chris Nunn for letting me feature his watch on the blog. **


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