Comments:
This message has been edited by tempocalypse on 2015-05-19 23:19:13
Black polished GO components
I'm always looking to learn more about the innards of these complicated machines. I heard it said that black polishing is one of the most exemplary forms of movement finishing. I am wondering which components are given this treatment in a Glashutte Original. I believe the screws are black polished prior to heat blueing and the GO website claims the swan necks are as well.
This message has been edited by tempocalypse on 2015-05-19 05:47:51
This brings me to my GO Panograph; I am still relatively new to very high end pieces but parts like that curved piece (right above the balance) providing tension to the pivoting train that engages the chronograph clutch, the top surface of the column wheel and the top of the bridge over the chronograph train (bottom left of picture) all seem to have an extremely high level of polish similar to the swan neck (to my eyes at least). I was under the impression that large components with black polishing is very very rare. I'm not experienced enough to be able to tell if these are merely well polished parts or if they are indeed examples of the celebrated black polishing technique, I would appreciate it if anyone could illuminate on this. Certainly the surfaces looked flawless under my loupe (don't know the magnification, its not that high and was designed for examining camera sensors)
Wait until you try your hand at it!
I once spent twenty minutes polishing a piece of metal inside a watch. Doing constant figure 8 loops on a sandpaper block.
Note, this was not technically black polish, as it was performed on a sandpaper block rather than on a tin metal block as required to be "black polish."
Note, this was not technically black polish, as it was performed on a sandpaper block rather than on a tin metal block as required to be "black polish."
I think any watchmaker who makes the mistake of letting me try such a thing would...
.. subsequently accuse me of working to actively destroy valuable components :p
I do get that black polishing of large components take a very long time, I've seen descriptions of balance bridges having been polished for 8 or 12 hours. Hence why I am curious about the rather large pieces such as the tip of the chronograph bridge on the cal 61.
I'll check with my colleague, Don C . . .
. . . and Our Man in Glashütte.
There might be a different terminology used in German watchmaking.
Cordially,
Art
There might be a different terminology used in German watchmaking.
Cordially,
Art
Thank you so much! ...
... I really appreciate it!
The terminology I found on the Manufactory section of the website used "Tin Flat Polishing". The copy is below. However they only made references to the swan neck, the regulator, screws, and sound springs. No mention of Column wheels or any of the other parts I was curious about. I dont know the proper terminology but I've sent the same picture with the parts circled and highlighted to GO as well but haven't heard back yet.
Ultimately it doesn't matter a great deal as those parts look beautiful, but still its good to know and learn 
Thanks again!
---
"In order to achieve an especially flat and lustrous surface, parts such as the swan-neck spring, regulator, or screw heads, which are particularly easy to view through the sapphire glass case back, are enhanced using the traditional but at the same time very labour-intensive process of tin flat-polishing.
In this process, diamantine (a polishing paste) is applied to a flat tin file, which the operator uses to file the surface of the part until it is completely even and gleaming. The process can take several hours and is checked continuously with the aid of a loupe. Polishing of a swan-neck spring (including the perimeters and angled edges) takes around 1 hour; to polish a sound spring such as that found in the “Pocket Watch No. 1” can take from 4 to 7 hours.
Tin flat-polishing has a technical as well a visual purpose. The surface of the material is enhanced and offers greater protection against damage by moisture in the air and oxidation."
Our Man in Glashütte . . .
. . . has replied!
"Hi Art,
Thank you for your question. Yes, tin polishing is also called “black polishing” and it is typical for traditional watchmaking art with a high approach (but not just used from Glashütte Original). It leads to a perfectly polished surface which appears deep black in the light reflection. The mentioned parts like on our website are correct.
Caliber 61 consists of many polished parts, e.g. all the edges of the movement frames get a pressure polishing (not with a tin file, but with a small rod/stick – makes it not easier…) Basically it is the same like tin polishing of beveled edges at steel parts, but the movement frames are made of brass and tin polishing is not possible here.
There are different kind of finish on the movement parts, some parts are e.g. paper-polished.
My best regards,
René"
There you have it, tempo; as I expected, the nub of your question has more to do with terminology than horology.
Cordially,
Art
"Hi Art,
Thank you for your question. Yes, tin polishing is also called “black polishing” and it is typical for traditional watchmaking art with a high approach (but not just used from Glashütte Original). It leads to a perfectly polished surface which appears deep black in the light reflection. The mentioned parts like on our website are correct.
Caliber 61 consists of many polished parts, e.g. all the edges of the movement frames get a pressure polishing (not with a tin file, but with a small rod/stick – makes it not easier…) Basically it is the same like tin polishing of beveled edges at steel parts, but the movement frames are made of brass and tin polishing is not possible here.
There are different kind of finish on the movement parts, some parts are e.g. paper-polished.
My best regards,
René"
There you have it, tempo; as I expected, the nub of your question has more to do with terminology than horology.
Cordially,
Art
Thanks Art! ...
... thats quite helpful.
Of course I never expected the anglage on the bridges to be black polished. My curiosity was most piqued by that jewel cap on the chronograph bridge. That said I think the response suggests that apart from the swan neck and regulator other polished parts must have been finished using other methods.
Black polish
Black polish is very time intensive work and if it is done on any parts it will most certainly be mentioned by the manufacturer in the movement description.
If they don't say anything in their sales/marketing material I would assume that it is not black polish, but just a very good polish.
What is black polish?
It is a particularly well done polish that is perfectly flat. That means tht all the reflections go in just one direction. The piece appears to be either a blinding flash of light reflections or perfectly black, as all the light falling on the piece is being reflected not to your eye, but somewhere else.
To get the perfectly flat surface the polish needs to be done on a hard flat surface, which is why it is most often done on a tin block. Even the best grades of polishing film are soft enough that the edges of the surface are rounded a little, you can see this easily under a loupe. For me the "perfectly flat" is the distiction between a very good polish and a black polish.
It will be interesting to hear what Glasshütte says about their parts finishing.
Best,
Don
If they don't say anything in their sales/marketing material I would assume that it is not black polish, but just a very good polish.
What is black polish?
It is a particularly well done polish that is perfectly flat. That means tht all the reflections go in just one direction. The piece appears to be either a blinding flash of light reflections or perfectly black, as all the light falling on the piece is being reflected not to your eye, but somewhere else.
To get the perfectly flat surface the polish needs to be done on a hard flat surface, which is why it is most often done on a tin block. Even the best grades of polishing film are soft enough that the edges of the surface are rounded a little, you can see this easily under a loupe. For me the "perfectly flat" is the distiction between a very good polish and a black polish.
It will be interesting to hear what Glasshütte says about their parts finishing.
Best,
Don
Thing is GO's descriptions...
...are quite perfunctory on their website. For instance the reference to swan necks being black polished is only within that one section within the manufactory section of the site. However, none of the movement descriptions even within the individual caliber pages make such a reference.
www.glashuette-original.com
This message has been edited by tempocalypse on 2015-05-21 00:37:24
www.glashuette-original.com
A video tour of the GO Manufactory I saw on youtube actually showed Tourbillon cages being tin flat polished but theres not a single reference to that fact on the Panolunar tourbillon page (or anywhere else on the website). So I suppose its possible GO have other black polished parts that they aren't talking about. My loupe unfortunately isn't powerful to really be able to confirm anything, and really compare the finish of the swan neck and regulator with the other parts.
re. the way light is supposed to reflect, I suppose you would need a single light source coming from 1 direction to judge it?
Anyway I wrote to GO just yesterday so lets hope they say something.
Thanks for clarifying the matter, Don. My sense . . .
. . . is that there may be a linguistic aspect to this as well, although one would hope the terminology used in watchmaking would be consistently interpreted across national borders.
Art
An annotated and detailed answer from Glashutte...
We've already had a response from Art's contact in Glashutte but I suppose the specifics can sometimes get lost in passing on a message. As mentioned earlier I had emailed a picture of the movement with the specific parts I was curious about to GO and I received a response today including the same picture annotated.
"... apologize for the delay in replying.
After consultation with our watchmakers, I can assure you that all highlighted parts in the picture are enhanced using the traditional process of tin flat-polishing. These movement components are lavishly polished by hand with a tin rod until they are completely event and very shiny.
I have assigned your marked parts with the associated technical terms, thus you have an exact overview of the movement – as you can see attached... "
Thus contrary to what Art had reported it would seem that apart from the screws, regulator and swan neck (which are mentioned on the website) these additional stainless steel parts have indeed been given a tin-flat polish or "black polish".
I would expect that other polished parts like the edges of bridges, edges and tips of chronograph levers and so on are the parts that have received paper or pressure polishes as mentioned in Art's response.
