WatchTech - probably a number of different ways

probably a number of different ways

Hello ALB,

A frosted finish like the one you're referring to can be achieved in different ways, presumably distinguishable by an expert, at least in person with a loupe.

Blasting with a specific grain and hardness of media can presumably get some similar results in an industrial fashion (and I think it's something of the sort that Grönefeld use for the relieved portion of their stainless steel bridges), but a more traditional method involves "rolling" the pieces on an abrasive compound on a textured surface.

It's similar to the techniques used for black polishing, but with a coarser abrasive and, instead of using zinc or something like that, you use frosted glass (for example). Both techniques involve a great deal of skill and patience to get good results, but they're distinctly different at the same time. Best guess is that's what Kari uses (on steel wheels at least).

A different sort of matte finish that I've never tried can be applied by a wire wheel with all but one or two bristles removed. George Daniels describes this technique in Watchmaking and this seems to be the technique Roger Smith uses for his frosted bridge decorations.

_john

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How is this finish achieved?

By: Ancienne Le Brassus : December 28th, 2012-12:30

Hi folks, Could somebody explain to me how this finish is achieved? My first impression is that it is sandblasted, but since the examples I see it most often (from my vintage watch perspective) are watches from the 1860 -70s, I am a bit skeptical. The fin...

The wavy lines?

By: andren : December 28th, 2012-19:32

Are you referring to the wavy lines? It's quite typical of the Waltham railroad pocket watches. Hopefully this picture will post: I recall, in my travels and conversations, that it was done on a machine similar to a pantograph with a small rotating sandin...

Sorry

By: andren : December 28th, 2012-19:34

I must have read it wrong. The matte finish is, indeed, produced by sandblasting or bead blasting. Romain Gauthier uses it as a finish on his watches.

Yes the finishing on the wheels :)

By: Ancienne Le Brassus : December 29th, 2012-15:37

Hi Andren, Yes, it was that other finish. But thanks for chiming in. The swirling finish is also very beautiful and a big draw for me on most of the US pocketwatches!! Happy New Year (a few days early!) S

probably a number of different ways

By: ei8htohms : December 28th, 2012-19:51

Very interesting thanks!

By: Ancienne Le Brassus : December 29th, 2012-15:42

Great, this is what i suspected. That there's sandblasting, but also that it can be done manually with the glass beads (although I didn't know with what compound and this answers it!) Would the the fine glass beads be used as in diamantine powder? I.e wit...

I'd be very surprised to hear about blasting being used traditionally

By: ei8htohms : December 29th, 2012-16:54

Hello ALB, Just to be clear, blasting (with sand, glass beads or what-have-you) is not a traditional watchmaking finishing technique in my experience and I'd be surprised to hear about any of the frosted finishes you've pointed out being created in that m...

Thank you for the follow up

By: Ancienne Le Brassus : January 8th, 2013-14:01

Thanks so much for taking the time to give me the page numbers and the clarification. I greatly appreciate it. I will order the material and give this finishing a try. If I achieve anything good, I will share the results :) Many thanks again for sharing y...

Sandblasted

By: info91 : December 28th, 2012-23:27

This is a sand blasting machine made around 1900 and it still works well ...

Operated with the foot?

By: Ancienne Le Brassus : December 29th, 2012-15:44

Thanks for posting this picture. Is it operated by pump action with the pedal on the floor creating the airstream?? Great picture and thanks for posting this machine! I looked up and saw that lots of gun parts are finished in this same way and now that I ...

Operated with the foot

By: info91 : December 30th, 2012-01:39

Its indeed operated with the foot. A big variety of ground material can be used for creating different structures. We shall also think about the difference of English and Swiss watchmaking at one point. Already at the end of 18th century Swiss companies h...

Thanks for this

By: Ancienne Le Brassus : January 8th, 2013-14:06

Yes, this reminds me of ebauche makers such as Japy churning out millions of movements. Thanks for the photos and sharing this info! Much appreciated!! S

Frosted finish.

By: paul.loatman : February 6th, 2013-12:08

Hello, I have done this frosted finish on many things. As has already been mentioned, you need granualized particles of something harder than the material you're finishing. I use silicon carbide honing powder, which is readily available and comes in diffe...