104 Ask The Ex­pert

In­trepid watch col­lec­tor and star horol­ogy blog­ger, SJX, lends a hand on all things watch re­lated

World of Watches (Singapore) - - Contents -

In­trepid watch col­lec­tor and star horol­ogy blog­ger, SJX, lends a hand on all things watch re­lated

Q: Are all DLC coat­ings the same in terms of hard­ness, dura­bil­ity, and ease of re­pair?

A: In short, no. Sev­eral forms of di­a­mond­like car­bon coat­ings ex­ist, all of which have sim­i­lar de­sir­able prop­er­ties like hard­ness, wear re­sis­tance, and a low co­ef­fi­cient of fric­tion. But the de­gree of these prop­er­ties can vary, with ac­com­pa­ny­ing trade-offs. Hard­ness means bet­ter scratch re­sis­tance, but at the same time, the harder the coat­ing, the more likely it is to de­lam­i­nate or peel off, es­pe­cially if the sub­strate (the un­der­ly­ing ma­te­rial) is dented or gouged. Coat­ings that are less hard have a bet­ter abil­ity to stick to the sub­strate even when the sur­face is de­formed. Re­pair­ing any type of DLC coat­ing is te­dious, which is why it’s rarely done. First, the coat­ing needs to be re­moved. Then, the sub­strate must be pol­ished to get rid of dents and scratches be­fore the sur­face is re­coated.

Q: Why do dif­fer­ent brands pre­scribe dif­fer­ent lengths of time for their watches’ ser­vice in­ter­vals? If my watch is still run­ning well and keep­ing time, do I re­ally need to send it in for ser­vic­ing?

A: Be­cause there is no hard and fast rule. There are two equally rea­son­able schools of thought on this. One is that reg­u­lar ser­vic­ing keeps ev­ery­thing in smooth run­ning or­der, pre­vent­ing ma­jor prob­lems from aris­ing. The other is that wait­ing un­til a ser­vic­ing is needed, mean­ing some­thing is bro­ken or mal­func­tion­ing, is more cost ef­fec­tive, since it saves on over­hauls in-be­tween.

My take is that watches need ser­vic­ing, but not as of­ten as watch man­u­fac­tur­ers rec­om­mend (of­ten three to four years), since few peo­ple wear their watches hard or of­ten enough to war­rant such ser­vice in­ter­vals. Be­tween six to eight years, maybe even 10, is sen­si­ble, es­pe­cially for some­one who owns mul­ti­ple watches, as each watch is not worn as of­ten. That be­ing said, some­one who wears a watch daily from work to the gym to the shower with­out respite will prob­a­bly need to visit the ser­vice cen­tre more fre­quently, es­pe­cially to check the seals to en­sure that mois­ture doesn’t get in.

Q: What are the ad­van­tages of us­ing hair­springs with ex­otic shapes, like the hemi­spher­i­cal one in Jaeger-lecoul­tre’s Re­verso Trib­ute Gy­ro­tour­bil­lon? What other shapes are there?

A: This is to en­sure isochro­nism, which is the con­stant rate of the bal­ance os­cil­la­tion through­out the power re­serve of the move­ment. When the main­spring is fully wound, the bal­ance wheel tends to ro­tate through a larger an­gle than when the main­spring is near empty. Isochro­nism means that the rate of the bal­ance os­cil­la­tion is the same, re­gard­less of the am­pli­tude (de­gree) through which it moves.

French watch­maker Edouard Phillips dis­cov­ered in the 19th cen­tury that a hair­spring with the same cen­tre of grav­ity as the bal­ance wheel is isochronous. To that end, var­i­ous so­lu­tions have emerged, in­clud­ing the Phillips curve, a bend in the hair­spring named af­ter the epony­mous watch­maker, as well as cylin­dri­cal hair­springs that were com­mon in ma­rine chronome­ters and pre­ci­sion pocket watches.

Other so­lu­tions to the same prob­lem in­clude Mont­blanc’s com­bined twin cylin­dri­cal hair­springs, one in­side the other, in its Tour­bil­lon Bi-cylin­drique. The down­side of hav­ing such fancy shapes is that they inevitably in­crease the height of the move­ment, since they are taller than a flat hair­spring.

Newspapers in English

Newspapers from Singapore

© PressReader. All rights reserved.