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Problems with polishing a watch case


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On 10/30/2017 at 11:15 AM, jdm said:

Of course they are. If you read my postings and watch the video (by the premier watchmaking school in the USA) above, you will notice that the idea is to abrading less, and move material with heat. These are the main advantages of buffing over a pure abrasive action.

I am having trouble with this notion of moving the metal, can you expand upon the mechanism?   I certainly don't know everything, but I know enough engineering and metallurgy to be very suspect of the claim.   

Abrasives, including fine ones like rouge are cutting tools and remove material in a chip formation process and there is no mechanism to reattach said material.   Metal only moves if heated to the point where it flows, or if enough force is applied for plastic deformation.  There is no way there is enough heat (1500 C needed) or forces involved for either.   

I would love to see quantitative proof  - say, a piece that with proper metrology equipment that could be shown to have be made thicker in a spot by polishing.

Edited by measuretwice
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2 minutes ago, measuretwice said:

I am having trouble with this notion of moving the metal, can you expand upon the mechanism?   I certainly don't know everything, but I know enough engineering and metallurgy to be very suspect of the claim.   

I will not launch myself into offering theoretical explanations or trying to prove what is well know already. All I can say is that even if I was doubtful at first, it works. Watch the video above and/or try yourself, it's actually very easy.

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yeah, I had seen that video awhile ago.  I don't think there is anything there indicating material had moved other than his claim of it .  I think he's very skilled but that doesn't mean the metallurgical explanation is accurate.   I was glad to see it raised here as it is so against the grain of engineering and metallurgy I was hoping for something more on why its "proven" or even how its suppose to work.  I confess I don't believe it and I've done lots of buffing, but if its true there should be proof or even a good scientific explanation and I will admit the errors of my ways.

If the claim is you're moving material about by buffing , are you able to take a piece and make it thicker in a spot and measure it?  That  would be very compelling if so :)

Edited by measuretwice
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yeah, I had seen that video awhile ago.  I don't think there is anything there indicating material had moved other than his claim of it .  I think he's very skilled but that doesn't mean the metallurgical explanation is accurate.   I was glad to see it raised here as it is so against the grain of engineering and metallurgy I was hoping for something more on why its "proven" or even how its suppose to work.  I confess I don't believe it and I've done lots of buffing, but if its true there should be proof or even a good scientific explanation and I will admit the errors of my ways.
If the claim is you're moving material about by buffing , are you able to take a piece and make it thicker in a spot and measure it?  That  would be very compelling if so [emoji4]
I agree. There is no way of physically "moving" stainless steel unless under extremely high temperatures. Even friction heat under a hard polishing mop doesn't come close.

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This is very strange that it's being denied, as has been said buffing is an established known effect and practice, I admit I don't know all the theory and it is impressive that it's possible, but it clearly is, I've personally observed it in how the shape of the surface has changed, never been tempted to get out a calliper, would feel as necessary as needing evidence to the sky being blue, I can see it. Exact same thing.

For what it's worth you would only need to heat the uppermost top layer to the necessary heat, even just getting a micron or 2 of steel to whatever is the necessary temperature would allow this process to happen, if slowly, (and my buffing is usually a patient, gradual process) and that temperature is most certainly not 1,500: the melting point of steel, steel would become annealed and be pliable to being slowly moved under a rapidly moving felt wheel, pressed against it, much sooner than that. theoretically starting about 700, which still sounds ridiculous until you remember you're only maintaining a micron or 2 of steel at this temperature at the time, and that heat rapidly displaces into the rest of the case, and let me tell you the case gets hot enough that I can easily believe it, I've burnt myself more than once when I've worked something a little too long without break.

 

Edited by Ishima
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The metal isn't going to flow at 700C, not stainless anyway.  The metal will move if its in either a molten state where they flow as a liquid, or it receives enough force (plastic deformation).  Even red hot on the anvil, it doesn't flow without a substantial force.  

imo the explanation for the discrepancy is that it would be difficult distinguish between how between material miraculously moved material to fill in scratch or just material formed around the scratch being removed by buffing such that things are now at the same level.  Somebody says the metal is moving and others accept it.  That buffing works and there is no scratch is not evidence that material has been moved.

If what you say is as clear as the clear blue sky, can you take a piece of material and make it measurably thicker in a spot by buffing?  (heat expansion not included)  If so, I'll be quiet :)

 

 

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It is not that easy for us to confuse. The changes we see in the metal we carefully work and check and watch all throughout is consistent with metal being moved, and would be inconsistent with metal being removed, it informs our entire approach when doing it, if it weren't accurate we simply wouldn't get the results we expect, and yet we do. I also believe there's an absence of data on the forces of buffing wheels, which makes theorizing with any accuracy impossible. Thank you.

Edited by Ishima
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It is not that easy for us to confuse. The changes we see in the metal we carefully work and check and watch all throughout is consistent with metal being moved, and would be inconsistent with metal being removed, it informs our entire approach when doing it, if it weren't accurate we simply wouldn't get the results we expect, and yet we do. I also believe there's an absence of data on the forces of buffing wheels, which makes theorizing with any accuracy impossible. Thank you.
Ishima, I don't think Measuretwice is in doubt about the final outcome. It is clearly working for you. What he does doubt (as do I) is that you are "moving" stainless steel surfaces at low melting points.

As a jewellery designer that works with silver and gold, I can move that metal with various compounds. With stainless however, I NEED to take down that metal to remove scratches or weld heavy dings and holes and refinish.

I really need to see this technique in action to believe it.

Can you upload a video on YouTube and send a link? I'm always curious about finishing so you've got my attention. [emoji16]

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Well, this is truly exasperating. 
This is just something I know.
I cannot make you know it. But I do know it. Any skepticism from those who do not falls short from that vantage point. 

So much about the broader subject of buffing/polishing/burnishing/finishing is ineffable, I've experienced that time and time again, and of all the people I've known who could do it, and obviously had a lot of knowledge, very few of them could convey more than the least thing about it. And I'm obviously not very good at that either.  

Edited by Ishima
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2 hours ago, Geo said:

Put simply, burnishing moves metal, buffing removes metal!

Succinctly put Geo.

@bojan1990 patience is the key. Each time you move up a grade you have to make sure that you remove all of the marks made by the previous grade before going up again. Use good quality wet/dry paper with water to help prevent clogging, and rinse the piece thoroughly between grades to ensure that there are no loose particles from the previous paper to foul the subsequent step.

You shouldn't really need to go above 2500 grit, after which switch to a polish like Solvol AutoSol on a soft rag and keep going until you get a deep lustre, then if you really want a top finish buff it up with a red Selvyt cloth. It works for me every time.

You can speed things up using a Dremel with a soft mop when you get to the Solvol stage but be careful to preserve the contours and lines of the case. They can disappear very fast and then they're gone.

 

 

 

Edited by Marc
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Marc, thanks for the help. I do have some questions related to the sandpaper:

1. Sandpapers that I have are P220, P550, P800, P1000 and P1500. How to know if they are made to be used with or without water applied?

2. Along with the above mentioned sandpapers, I do have Silicon Carbide 800/2400 and 1200/4000 sandpapers. I am not sure which grade are they, since there are two numbers presented on them. They are very very fine and distinguish themselves from the rest of the sandpapers. All of the sandpapers that I have (both P and Silicon Carbide) are circular shaped. 

3. I bough a polishing paste here in Germany, it says that the grade is 4 (medium) and the shine level is 7. The paste is pure white, density is a little bit less than the tooth paste, similar to Solvol AutoSol. May I use it for the final touch?

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Marc, thanks for the help. I do have some questions related to the sandpaper:
1. Sandpapers that I have are P220, P550, P800, P1000 and P1500. How to know if they are made to be used with or without water applied?
2. Along with the above mentioned sandpapers, I do have Silicon Carbide 800/2400 and 1200/4000 sandpapers. I am not sure which grade are they, since there are two numbers presented on them. They are very very fine and distinguish themselves from the rest of the sandpapers. All of the sandpapers that I have (both P and Silicon Carbide) are circular shaped. 
3. I bough a polishing paste here in Germany, it says that the grade is 4 (medium) and the shine level is 7. The paste is pure white, density is a little bit less than the tooth paste, similar to Solvol AutoSol. May I use it for the final touch?
Do you have a dremel drill that you can attach a small buffing wheel to? Or a proper polishing motor? Really that will give you the best final finish. One of the many compounds you can use on these buffing wheels is Hyfin. It's great for steel. Not sure about the paste you mentioned, are you going to rub this in by hand?

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2 minutes ago, hir3na5hra said:

Do you have a dremel drill that you can attach a small buffing wheel to? Or a proper polishing motor? Really that will give you the best final finish. One of the many compounds you can use on these buffing wheels is Hyfin. It's great for steel. Not sure about the paste you mentioned, are you going to rub this in by hand?

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You can because that's how I polish. However to buff you need  one of these.

 

59fc2d4153218_ScreenShot2017-11-03at08_47_33.png.f79898d3ddffb27b5dc0ed9df461b39c.png

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3 hours ago, bojan1990 said:

Marc, thanks for the help. I do have some questions related to the sandpaper:

1. Sandpapers that I have are P220, P550, P800, P1000 and P1500. How to know if they are made to be used with or without water applied?

2. Along with the above mentioned sandpapers, I do have Silicon Carbide 800/2400 and 1200/4000 sandpapers. I am not sure which grade are they, since there are two numbers presented on them. They are very very fine and distinguish themselves from the rest of the sandpapers. All of the sandpapers that I have (both P and Silicon Carbide) are circular shaped. 

3. I bough a polishing paste here in Germany, it says that the grade is 4 (medium) and the shine level is 7. The paste is pure white, density is a little bit less than the tooth paste, similar to Solvol AutoSol. May I use it for the final touch?

@bojan1990 The P sandpaper grit sizes that you have sound about right, however, you say that they are circular sheets. This suggests to me that they are intended for use with a mandrel or backplate on a power tool as a sanding disc, and as such they are unlikely to be a wet/dry type abrasive. I'm not sure about the silicon carbide papers that you mention as they seem to refer to two different grades but again being circular suggests that they are designed for use with a power tool and therefore unlikely to need to be waterproof.

The papers that I use are 3M wet/dry (or waterproof) silicon carbide papers designed for the automotive refinishing industry. They are good quality, inexpensive, and fairly easy to get hold of (just google 3M wet/dry). Whatever you use though if it doesn't state that it is waterproof then it probably isn't, and if you want to test it just leave a piece in some water for 10 minutes and then see if the paper remains sound and the abrasive doesn't just rub off.

Use the paper with plenty of water. This helps to stop the paper clogging which in turn results in a better finish and prolongs the useful life of the paper. It also helps to flush away any grit that does dislodge from the paper as well as the removed metal, both of which can degrade the finish if alowed to remain.

The polishing paste that you mention sounds as though it should be ok and will likely result in a good finish, certainly if it is comparable to Solvol you will have no problems. It will also double as an excellent finish for polishing acrylic crystals (incidentally this entire process works just as well to restore scratched acrylic crystals).

For a final finish I use a red Selvyt cloth which is basically a polishing cloth impregnated with rouge. This also is what I use to maintain the finish of a watch during normal use; once a month or so just giving it a quick wipe over to briong it back to sparkling, although this is probably not the best idea with a plated finish.

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28 minutes ago, Marc said:

@bojan1990 The P sandpaper grit sizes that you have sound about right, however, you say that they are circular sheets. This suggests to me that they are intended for use with a mandrel or backplate on a power tool as a sanding disc, and as such they are unlikely to be a wet/dry type abrasive. I'm not sure about the silicon carbide papers that you mention as they seem to refer to two different grades but again being circular suggests that they are designed for use with a power tool and therefore unlikely to need to be waterproof.

The papers that I use are 3M wet/dry (or waterproof) silicon carbide papers designed for the automotive refinishing industry. They are good quality, inexpensive, and fairly easy to get hold of (just google 3M wet/dry). Whatever you use though if it doesn't state that it is waterproof then it probably isn't, and if you want to test it just leave a piece in some water for 10 minutes and then see if the paper remains sound and the abrasive doesn't just rub off.

Use the paper with plenty of water. This helps to stop the paper clogging which in turn results in a better finish and prolongs the useful life of the paper. It also helps to flush away any grit that does dislodge from the paper as well as the removed metal, both of which can degrade the finish if alowed to remain.

The polishing paste that you mention sounds as though it should be ok and will likely result in a good finish, certainly if it is comparable to Solvol you will have no problems. It will also double as an excellent finish for polishing acrylic crystals (incidentally this entire process works just as well to restore scratched acrylic crystals).

For a final finish I use a red Selvyt cloth which is basically a polishing cloth impregnated with rouge. This also is what I use to maintain the finish of a watch during normal use; once a month or so just giving it a quick wipe over to briong it back to sparkling, although this is probably not the best idea with a plated finish.

I will try to put some pieces of sandpaper in water for 10 minutes, and then I will see if they are suitable to use with water.

Anybody has idea about these Silicon Carbide 800/2400 and 1200/4000 sandpapers? Which grade are they actually?

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6 hours ago, hir3na5hra said:

JDM.... Take note.

As mentioned already I have left this discussion, it's not my duty to educate. Feel free to sandpaper your or your friend' s watches, just.don't don't expect to be told that is right by anyone that does it the correct way.

Edited by jdm
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I personally prefer to have more control of refinishing a case by way of using glass paper by hand using a flat piece of wood, this way I can observe every aspect of the case in more detail, and have complete confined control of the refinishing process.  The once I'm happy, then I move onto two stages of 5cm rotor wheels, and finally a light refinishing of polished areas with cape cod.

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I personally prefer to have more control of refinishing a case by way of using glass paper by hand using a flat piece of wood, this way I can observe every aspect of the case in more detail, and have complete confined control of the refinishing process.  The once I'm happy, then I move onto two stages of 5cm rotor wheels, and finally a light refinishing of polished areas with cape cod.
Indeed. For cases with crisp edges, some wet n dry paper on a wood stick is excellent for control. There's always a greater level of risk with grinding burrs or those diamond impregnated rubber burrs. Very easy to over grind.

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Indeed, I simply prefer to get intimate with the work on any watch case, and not treat it like a piece of metal, in my experience, each and every watch has soul, and owners have a personal attachment to them, which deserves the personal touch.  No complaints in the years I've been refinishing cases, and bracelets, yes, it takes longer than machine polish, but this to me is worth is, I'm not a machine, my customers are prepared to wait that extra time for the personal touch.

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