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First attempt at polishing bridge screws


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I brought a clone Unitas 6497 for my watch repair course. Whilst learning the autonomy of this movement? I really hated those blue laquer screws. So I decided to file off the laquer with a diamond filer. I purchased loads of diamond paste grit, which came in a syringe. Peg wood and pin vice was all that was needed. God knows how many hours and days it took me?  But here's the result. The pic was before polishing.

 

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Good question! I secured the screw on a small pin vice and then cut a flat surface on the peg wood, about an inch. It has be flat, so I kept checking on a 12x mag. You then start off with the low grit and work your way up to 10k grit. Theres 12 grit to get that finish. Put plenty paste on and work in a circular motion, with gentle pressure. So you only feel the paste and the head of the screw rubbing. I would say the finish is black polish. Hope this helps.

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1 hour ago, VWatchie said:

Sweet! :thumbsu:

Not sure how you did this. Did you place the diamond paste on the head of the screw and then polished it with peg wood?

Give it ago! I guarantee you, you'll be amazed with the result after each grit polish. That's under the loupe!

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7 hours ago, Jon said:

How long did it take to do one screw to that finish?

I'm curious too, but I imagine it took some time! Those look great. A lathe sure makes polishing rounded head screws easy; if you have a micromotor (hand motor, i.e. Dremel or similar) you can chuck the screws there and charge wood with your diamond or whatever abrasive to speed things up.

 

Black polish is a flat polish, as flat possible. It is pretty much universally done (even in production) using metal laps, soft metal like tin or zinc, and a tripod tool with two adjustable feet, the third being the part/screw, or in production the screws are fixed to a plate many at a time and polished flat all at once.

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8 hours ago, nickelsilver said:

I'm curious too, but I imagine it took some time! Those look great. A lathe sure makes polishing rounded head screws easy; if you have a micromotor (hand motor, i.e. Dremel or similar) you can chuck the screws there and charge wood with your diamond or whatever abrasive to speed things up.

 

Black polish is a flat polish, as flat possible. It is pretty much universally done (even in production) using metal laps, soft metal like tin or zinc, and a tripod tool with two adjustable feet, the third being the part/screw, or in production the screws are fixed to a plate many at a time and polished flat all at once.

I know these dont actually qualify to be classed as black polish, as my edges are not at true 90 degree, But at an angle they do appear black, this was what I actually meant. That's because of the mirror finish I have given it. To get a true black polish, you need a true 90 degree on edges of the screw head and a mirror finish. I did all by hand, no machines, lathe etc.

 

A member of my family is a watchmaker graduated from " W.O.S.T.E.P he challenge me to it. And showed him without all the fancy tools what can be achieved?

 

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16 hours ago, Jon said:

How long did it take to do one screw to that finish?

I lost track of time. But it took a good few days. 8 hrs at a time, without a break. There were 12 grits I worked with, from grit 320 all the way to grit 10000. Under the loupe I'm really proud of the result. I actually aiming to heat blue these screws soon. 

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Ha, that's cool! I went to WOSTEP too, but a long time ago. I still have the rudimentary tripod tool I made in school (before going to WOSTEP), and a better tripod and a bunch of tin blocks now. When I was in school the rumor was that the foil on wine bottle necks made the best polishing blocks, but I never drank enough wine to collect enough foil to make one.

 

If you heat blue don't be surprised if you don't get a totally uniform blue the first try. But you can take it off with the last grit you used. Also, the slots probably won't blue, I think these screws are plated.

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1 hour ago, nickelsilver said:

Ha, that's cool! I went to WOSTEP too, but a long time ago. I still have the rudimentary tripod tool I made in school (before going to WOSTEP), and a better tripod and a bunch of tin blocks now. When I was in school the rumor was that the foil on wine bottle necks made the best polishing blocks, but I never drank enough wine to collect enough foil to make one.

 

If you heat blue don't be surprised if you don't get a totally uniform blue the first try. But you can take it off with the last grit you used. Also, the slots probably won't blue, I think these screws are plated.

Cool! Are you referring to ones of these? My brother in law made it at wostep. Heat blue is a trail and error for me. So thanks for the tip.

IMG-20200209-WA0008.jpg

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Cool! Are you referring to ones of these? My brother in law made it at wostep. Heat blue is a trail and error for me. So thanks for the tip.
IMG-20200209-WA0008.thumb.jpg.a7633a61e7b2743f04a37a17b76c1e5c.jpg
Totally!- that's almost identical to my first one. I'll post a pic tomorrow of it, my current one and another from a WOSTEP grad who just finished about a year ago.
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4 minutes ago, nickelsilver said:
37 minutes ago, Craven279 said:
Cool! Are you referring to ones of these? My brother in law made it at wostep. Heat blue is a trail and error for me. So thanks for the tip.
IMG-20200209-WA0008.thumb.jpg.a7633a61e7b2743f04a37a17b76c1e5c.jpg

Totally!- that's almost identical to my first one. I'll post a pic tomorrow of it, my current one and another from a WOSTEP grad who just finished about a year ago.

Cool.... Was it a unitas 6497 cased and have it cosc, you had to make?

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Here's the tripods, left is my rustic one from school, then a very old but good commercial one I use (it has a little collet holder for Schaublin P4.5 collets which I have a bunch of), then the one my friend made at WOSTEP. The other pic is a tin block, and a glass plate with 12 micron paper on it. Get the screw in the tool, level, touch up on paper, clean off, then on the tin. Start to finish is just couple of minutes for most screws. I use 0.5-1micron diamond on the tin.

tripods (Large).jpg

tin block (Large).jpg

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Here's the tripods, left is my rustic one from school, then a very old but good commercial one I use (it has a little collet holder for Schaublin P4.5 collets which I have a bunch of), then the one my friend made at WOSTEP. The other pic is a tin block, and a glass plate with 12 micron paper on it. Get the screw in the tool, level, touch up on paper, clean off, then on the tin. Start to finish is just couple of minutes for most screws. I use 0.5-1micron diamond on the tin.

709264758_tripods(Large).thumb.jpg.bfa007c32c3263e4ddf41ea463e6210d.jpg

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You're a pro mate! Are you in th UK? You have the right tools for the right job! My brother just gave me a lecture, regarding not using a tripod for polish. You WOSTEP boys are hard to please!

I'm glad to have a knowledgeable guy like you around here. I shall seek advice from you in the near future!

 

Here a pic of my brother in laws 6497 from scatch he made Manchester Wostep

 

The bridges are made of german silver whatever that is? He describes it as very soft and easily tarnish by just breathing onto it

 

 

Edited by Craven279
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I'm in Switzerland (but a Yank).

Wonder what the argument was against tripods? There are hand powered screw head polishing "lathes", I coveted them as a youth and have one, but haven't used it in ages. By design they take off more material than a tripod, which can be a real issue when restoring or with very small screws. And a tripod can do any flat part...

That movement looks awesome! I really love simple but well executed finishing like that, it looks easy but it sure as heck ain't to come out as clean as that. Class click too!

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The arguement was my method of polishing. As I cannot get a true flat 90 degree polish. Making the screw head appearing to be rounded? Which is true! But I'm just hobbyist and they look good enough for me? And when I say that? He says "it sounds like you're giving up" therefore you cant please them all. But I love him!

Edited by Craven279
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The arguement was my method of polishing. As I cannot get a true flat 90 degree polish. Making the screw head appearing to be rounded? Which is true! But I'm just hobbyist and they look good enough for me? And when I say that? He says "it sounds like you're giving up" therefore you cant please them all. But I love him!
Your screws are great, a bit rounded is ok (if intentional haha).

Did you tell him how much time you spent? Most would have given up.
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12 minutes ago, nickelsilver said:

Your screws are great, a bit rounded is ok (if intentional haha).

Did you tell him how much time you spent? Most would have given up.

Yes he know the time I put in. I dont do this for a living. Just fun and knowledge, so time doesn't matter and it's part of the learning kerb.

I'll will do a update once the screws are blued ok? I can take any criticism with no hard feelings. As this will only improve me to become better.

Thank you mate

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