The Breitling Watch Source Forums

A simple question. I know that most oils such as those used in industry and auto are rated on viscocity or how well they "flow" at certain temperatures or in other terms the relative thickness of the oil at a certain temperature. I can assume that oils used in watches by the very fact that too are oils have a similar rating. I have done some quick internet searches and found that like oils used in autos watch oils come in a variety of viscocities as well. In my research it appears that the lower limit of watch oil, in regard to temperature function, and subsequent inability to adequately lubricate, is around 0 degrees Farenheit for some oils and others are rated down to as much as -61 Farenheit.

This link is where I have gleened my info:
http://www.ofrei.com/page246.html

Judging from that link it appears that some watch oils have a viscocity rating where the optimum operating range is only down to 0 degrees farenheit. I would assume then that below that temperature the oil thickens and becomes sluggish. In a watch I am uncertain if this would have any serious effect or if it would just possibly just cause the watch to run slower. In an automobile this is primarily a concern with initial cold start up. The thickened oils don't flow freely and as such vital metal components are deprived of lubrication until the oil thins. The automotive industry overcomes this by blending oils to provide lubrication at temperature extremes.

Now to my questions. I would think in watches the primary concern would be thinning of the oils rather than thickening but in the link I posted I don't see any reference to the upper temperature limits. Therefore I feel I am probably flawed in my thinking.

Is there an upper temperature where watch oils become a concern (I can imagine someone keeping a watch locked in a hot car on a summer day) and should exposing a watch to less than 0 farenheit be a concern?

Thanks guys.

I use Moebius Synt-a-Lube 9010 for normal use and 9020 for heavy duty use (mainsprings are the obvious place).

The specs have viscosity ratings at 0, 20 and 50 celsius (32, 68 and 112 fahrenheit) and are pourable to -40 celsius (-40 fahrenheit). 9010 has an operating range of -29 to +70 celsius (-20 to 158 fahrenheit) and 9020 has an operating range of -18 to +80 celsius (0 to 176 fahrenheit).

Watch oil is designed to stay in one place - at the point of lubrication, and so are very stable with only very minor changes in viscosity at different temperatures. If you use a good oil then you won't have any practical problems until the oil ages.

Thanks so much Roff.