Jump to content

Polishing Results

jdrichard
 Share

Recommended Posts

jdrichard Distinguished Member

jdrichard

Posted
  • Author
Posted
9 minutes ago, KarlvonKoln said:

Indeed yes!  A fine job of it.  What materials and methods work best for you?

New polishing motor with three pads, progressively finer.  use Stainless steel polish lightly on the first pad and fine blue on the last pad.  seems to work well.  maintain heat through pressure to melt the metal into itself....an art that gets better with practice.

  • Like 1
  • Thanks 1
Link to comment
Share on other sites
jdrichard Distinguished Member

jdrichard

Posted
  • Author
Posted
16 minutes ago, Klassiker said:

Hard to imagine a better result than that!

What do you mean by this?

to buff out all the scratches, you are in fact not removing material, you are melting the high points into the low points.  Friction + heat and that is how it is done.  Works great on Stainless Steel watches and this is an Omega pocket Watch with a Silveroid metal, which is in fact a Nickle Copper compound.

Link to comment
Share on other sites
HectorLooi Distinguished Member

HectorLooi

Posted
Posted
3 hours ago, jdrichard said:

to buff out all the scratches, you are in fact not removing material, you are melting the high points into the low points.  Friction + heat and that is how it is done.  Works great on Stainless Steel watches and this is an Omega pocket Watch with a Silveroid metal, which is in fact a Nickle Copper compound.

I think this is a misconception perpetuated by one YouTube video on polishing. Nowhere in material science literature have I come across this explanation.

Silver melts around 900°C and stainless steel around 1300°C. If the friction is enough to cause the surface to melt, the polishing mop would burn.

Burnishing can move material from high spots to low spots by plastic deformation. You have demonstrated that in many of your pivot polishing videos. But the forces involved in burnishing are much higher. The force generated by pressing an object into a buffing mop cannot generate sufficient force to move metal molecules. 

When polishing thermoplastics like acrylic, if too much pressure is applied until it melts, it never a good thing. The mop would gouge out the softened surface.

  • Like 1
  • Thanks 3
Link to comment
Share on other sites
jdm Distinguished Member

jdm

Posted
Posted
On 4/2/2021 at 12:43 AM, HectorLooi said:

I think this is a misconception perpetuated by one YouTube video on polishing. Nowhere in material science literature have I come across this explanation.

I suppose the video to which you referring is the following, by a reputable American watchmaking school

Quote

Silver melts around 900°C and stainless steel around 1300°C. If the friction is enough to cause the surface to melt, the polishing mop would burn. 

Burnishing can move material from high spots to low spots by plastic deformation. You have demonstrated that in many of your pivot polishing videos. But the forces involved in burnishing are much higher. The force generated by pressing an object into a buffing mop cannot generate sufficient force to move metal molecules. 

This discussion has been done on our forum already in the past. I do not have anything to object to the physics explanation and tests done to say that buffing cannot move material. My only point, then and now, is that in practice with buffing one can acceptably repair some damage without excessive abrasion or micro-welding.

That comes not only from my personal experience, as the Master in the video above and many other repairers share my same opinion - it just works. If you haven't ever tried it I recommend that you do. Case restoration is very rewarding and in demand.

 

  • Like 1
Link to comment
Share on other sites
jdm Distinguished Member

jdm

Posted
Posted
7 minutes ago, dadistic said:

Oh boy. When I first saw this claim about melting metal on the video from perplxr I almost choked on my coffee. 

He never used the verb melting, if he did I didn't catch that. 

Just curious if you have ever done any sort of similar work yourself?

Link to comment
Share on other sites
dadistic Distinguished Member

dadistic

Posted
Posted

Not watch case polishing, but in machining surface finish can be a big deal. We have had to get some gnarly micro finishes at times. We have engineers that understand this very well. Also, at one time I had some exposure to the manufacturer of lapping machines that were used for polishing the silicon wafers used in semiconductor manufacturing (my friend worked for them, and we discussed the tech a lot). Probably the most exacting surface requirements there are, and there was no melting involved ? I used to have some test wafers that I got from him, they were quite something, but I don't know what happened to them. Was quite a few years back. Actually, at this point, everything was quite a few years back ?

The oversimplified rule is that it is the size of the scratches that matters when creating a finish. But don't take my work for it, ask an engineer who has experience in this area. 

Cheers! 

Link to comment
Share on other sites
jdm Distinguished Member

jdm

Posted
Posted
6 minutes ago, dadistic said:

Not watch case polishing, but in machining surface finish can be a big deal.

Your answer is a lot like the ones that went into the other long topic on the subject - sorry I could not find it yet. Someone which had a machine shop (or hobby ?) went to measure with a micrometer the abrasive effect of buffing some deep gauges he did to some metal. No surprise, it was abrasive, nobody claims otherwise.

But this type of repair has nothing to do with theoretical metallurgy, machining or other craft or science. It is just about using a motor (even a rotary tool works to some degree), a felt wheel and a compound of some sort. Get a stainless steel case with some scratches or dings, and buff it staying away from edges. Start with minimum damage, find how much damage you can actually repair without creating visible valleys or the like. Report here if you like. 

 

Link to comment
Share on other sites
jdrichard Distinguished Member

jdrichard

Posted
  • Author
Posted
On 3/31/2021 at 8:03 PM, PeterS said:

I'll be starting on the Waltham pocket watch this weekend.
You've already advised me that I can't wind the mainspring via the ratchet wheel and helped me with oiling.

This is my first pocket watch and I'm more used to the more modern movements. I would appreciate if you could let me know what to watch out for, what to be careful with etc. Stuff that differs from wrist watches.

Couple of questions:

Do I need to unscrew the jewels from the bridges? I will have to remove the jewel from the balance to clean it properly but I'm not certain about the other jewels. I presume that It will be straight forward putting them back?

Is the crown wheel screw reverse threaded?

Detaching the crown, is there a chance I may strip the tread on the stem?

Pictures of the jewels and the movement are below.

 

P3311014.JPG

P3311030.JPG

P3311094.JPG

 

25 minutes ago, dadistic said:

Not watch case polishing, but in machining surface finish can be a big deal. We have had to get some gnarly micro finishes at times. We have engineers that understand this very well. Also, at one time I had some exposure to the manufacturer of lapping machines that were used for polishing the silicon wafers used in semiconductor manufacturing (my friend worked for them, and we discussed the tech a lot). Probably the most exacting surface requirements there are, and there was no melting involved ? I used to have some test wafers that I got from him, they were quite something, but I don't know what happened to them. Was quite a few years back. Actually, at this point, everything was quite a few years back ?

The oversimplified rule is that it is the size of the scratches that matters when creating a finish. But don't take my work for it, ask an engineer who has experience in this area. 

Cheers! 

I did take Strength of Materials in Engineering University, but then went on the Electrical Engineering where the only thing you melt is circuits by to much power input:) I will need to ask my son the Mech Eng.  I like the melting explanation as it seems to make some sense, however, if the melting point of SS is really high, the question is can it get pliable enough to move.

Link to comment
Share on other sites
HectorLooi Distinguished Member

HectorLooi

Posted
Posted

Looks like JD brought it out and I reopened the can of worms.

I've polished all sorts of stuff. From soft stuff like wax, plastics, resins and 24K gold. Metals like aluminium, copper, brass, bronze, silver, gold, steels, stainless steels, nickel alloys, tungsten carbide. Hard, brittle stuff like glass, ceramics, zirconia.

I think we've all polished stuff and our personal experience guides our thinking. Some arguments can never be settled so lets just end it here and remain friends.?

Link to comment
Share on other sites
jdrichard Distinguished Member

jdrichard

Posted
  • Author
Posted
12 hours ago, HectorLooi said:

Looks like JD brought it out and I reopened the can of worms.

I've polished all sorts of stuff. From soft stuff like wax, plastics, resins and 24K gold. Metals like aluminium, copper, brass, bronze, silver, gold, steels, stainless steels, nickel alloys, tungsten carbide. Hard, brittle stuff like glass, ceramics, zirconia.

I think we've all polished stuff and our personal experience guides our thinking. Some arguments can never be settled so lets just end it here and remain friends.?

I’m good with that:) I do have a question however. Does anyone know where the guy in he “perplxr “ video got the framed loupe that he is wearing in the video? It goes around the circumference of the glasses to hold the flip-down loupe on the top.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
 Share
Go to topic listing


  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • Waggy
      Rado rotor removal

      By Waggy · Posted

      Not sure, but just looking at it, it seems like the screw on the right may be a fake? The one on the left may not be a screw in the regular sense at all, rather a 2 position device, I think you need to point the slot towards either of the 2 dots and one will secure and one will open. Like I said this is just my best guess looking at the pictures.
    • doober
      Rado rotor removal

      By doober · Posted

      Hi! I am in the process of restoring a rado captain cook mkII. I want to remove the rotor, but I am not sure how to and need some help. As you can hopefully see on the photo there are 2 screws. The left one has two positions, the right one looks like a regular screw. I have tried turning the right one, but it does not give even after using more force than I would expect. Anyone know the function of the left screw with the two positions and how to remove the rotor? Thanks!!
    • Randy55
      Introduction

      By Randy55 · Posted

      Welcome to the group Stirky. You can search for just about every subject in the craft here. Don't be afraid to ask if you can't find the answer that may have already been covered ( some ad nauseum LOL ). You don't have to buy Bergeon to get good quality. There are many decent mid-range tools available that will last you a lifetime. Cousins would be a good place to start . Cheers from across the pond ! Randy
    • Jon
      What are these Seitz B-Jewels?

      By Jon · Posted

      I picked up a similar amount of these jewels some years ago in a watch and clock fair. Every now and then they come in handy. This week I've got a rubbed in bombe jewel in the balance cock that is cracked and needs replacing. Very handy to have a vintage assortment of these type of jewels!
    • Stirky
      Diagram for 6497 motion works

      By Stirky · Posted

      Thanks Jon.
×
×
  • Create New...