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Presently: Bevelling and finishes in top-of-the-range watchmaking (II)

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The author

Having acquired an educational background in economics and literature, Caroline Sermier fell in love with watchmaking right from her arrival at Renaud & Papi.
Her current responsibilities as head of the communication department allows her to blend a taste for writing with her fascination for complicated watches, and particularly for the finishing and decorative details on top-of-the-range luxury watches.

13. Bevelling and finishes in top-of-the-range watchmaking (II)

Foreword

Representing far more than a mere functional necessity, watchmaking finishes correspond to a philosophy : passion and respect for tine workmanship, as well as the desire to enrich a part through the care devoted to even the slightest details. In the pursuit of aesthetic perfection, each detail is important because it contributes to enhancing the watch as a whole. From this standpoint, it is important to grasp the difference between finishing and decoration. Decoration implies ornamentation, an adornment that will embellish the part (cote de Genčve, chasing, engraving etc…) ; on the other hand, the only value added of the finish is the quality of the craftsmanship.


Preamble to hand-bevelling

Finishing a movement consists of performing all the decorative operations once the functional machining work has been completed. All the surfaces of parts are touched up, corrected and decorated by hand.
On the diagram to the right :
A) The top surface
B) The flank
C) The external angle
D) The interior angle
E) The rounded angle
The hatched lines show the BEVEL or the chamfer

Bevelling is one of the finishes most representative of high-end watchmaking, consisting of cutting down and polishing the angles, known as chamfers. The outline of the shape is thus underscored as the light lays over the bevels. (hatched lines on the diagram above).
The following tools are used for chamfering the parts : files, buffs, burnishers, stones and polishing lathe. Bevelling is an extremely meticulous task enabling the elimination of traces of machining and unattractive burrs that might also impede the smooth running of the mechanism.
Rough part * (1) : After machining, and prior to decorations. Precision-machined parts could in fact, once trimmed, be immediately fitted in the movement, as they are operational.
Interior angle * (2) : this applies to the place where two bevels meet on an inside corner. It must look like a single geometrical line where the two bevels meet.
No machine is capable of creating an interior angle.
It is a very difficult type of finish that calls for expert hands.
Rounded angle * (3) : In this case, the intersection of the chamfers is rounded. This type of bevel is not as difficult to achieve as an interior angle.
External angle * (4) : This is an angle formed where two bevels meet towards the exterior. This angle must be sharp and neither blunt nor rounded.

 

Bevelling : its usefulness

This cut-down angle is first and foremost a form of trimming which makes the parts less fragile during handling: moreover, polishing limits the risk of corrosion. Parts could be roughly trimmed, but the determination to accomplish a fine piece of workmanship and to create optical effects leads the craftsman to polish the chamfer. (Photo 5)

Note :
- (photo 6) non-decorated prototype of a grande sonnerie minute repeater mechanism
- (photo 7) decorated movement of a grande sonnerie, minute repeater, carillon, power-reserve and dynamograph mechanism

Aesthetic criteria of bevelling : regularity is important. The bevel must not start off small and end up larger.
The curve of the bevel should be beautiful : the angle is curved or very slightly rounded It is crucial that the bevelled edge be clean , even under a magnifying glass.
Twisted bevels are not pleasing. The bevel may be regular but must not twist like a propeller blade.
Faceted bevels are unacceptable, as they give an unrefined appearance.
Dull patches are dark. The quality of polish must be impeccable.

Subjective ?
A watch with no decorations, but which has nonetheless been carefully assembled, works very well* (photo 6), yet the watch appears lifeless and lacks luminosity: one might say it has no soul. The absence of a fine finish detracts from the effect of the precision devoted to the parts in mechanical, horological and assembly terms.

On the other hand, (photo no. 7) provides a better idea of just how meticulous the work of bevelling actually is, requiring tremendous dexterity. One might nonetheless argue that all these efforts imply a great deal of time and serve no functional purpose ; nonetheless, is it not obvious that this all-but forgotten art gives each part a remarkable aesthetic finish that enhances the appeal and value of the watch as a whole ?

See: Bevelling and finishes...(I)

 










 

   

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