Whizzing

On Oct 1, 3:20 am, Reid Goldsborough
wrote:
On Sun, 30 Sep 2007 15:49:06 -0700, Jorg Lueke
wrote:

I am curious with what revision the updated understanding was added.

Your understanding of the "updated understanding" in incorrect. It
wasn't updated.
No, it's been that way since the 1st edition?

The same language appeared in both the 5th and 6th
editions. Only you left out important information, specifically this
sentence immediately following what you quoted:"Under high
magnification (in this case a very strong magnifying glass should be
used) the surface of a whizzed coin will show countless tiny scratches
as well as metal build-up on the edges of letters and numerals." In
other words, metal moves. It's not nice to leave out information like
this. Is some metal abraded? No doubt, as I said earlier, some tiny
amount of metallic dust, but so little that it's not measurable with
the scales typically used to weigh coins, not to the second or third
decimal point on a gram scale. That's really tiny.

Where in the ANA book does it state that the abrasion is so little
that it's not measureable? Furthermore is weight really relevant, if
the abrasion can be detected by sight does the physical amount matter
at all?

I also said that metal is abraded and moved based on the ANA guide
information "Based on the current ANA information I would read both as
happening. Obviously the abrasion referred to above which leaves the
scratches
removes metal. Some of that builds up around letters and devices,
which for my money can be defined as moved metal."
Perhaps you didn't read down this far into my post?
The dictionary of grading terms makes it even more clear "whizzing -
The alteration of a coin's appearance by use of a rotating bristeld
(wire or other material) brush to move or remove metal from the
surface."


I also left out information, in what I quoted earlier from the ANA
grading guide. I forgot to mention that the part I quoted was from a
chapter bylined by Michael Fahey. This doesn't affect the truth of
what I quoted like what Jorg just did,
I said metal is abraded and moved in my conclusion. This based solely
on the ANA book. What part of my conclusion is erroneous? I also
didn't add my spin to the printed information.

but I should have noted it.
Michael Fahey is currently a grader for ICG and before that was a
grader for ANACS, for 25 years. He's also a columnist for Coin World.

I can't find a chapter bylined by Michael Fahey were he mentions, "As
the wire brush moves across the surface of the
coin, a microscopic layer of metal is liquefied BY THE HEAT produced
by friction." Could you note the page where this quote can be found?

On Sun, 30 Sep 2007 19:20:16 -0700, RF wrote:

Please point out where this was said or admit you're nothing but a
lying windbag.

It was "Oly" who said that. That's not you? g You trollers are all
the same, having the instincts of a fifth grader. "Look at me!" And I
engage you. I'm wrong. g I really am here. No more.

--

Email: (delete "remove this")

Consumer: http://rg.ancients.info/guide
Connoisseur: http://rg.ancients.info/glom
Counterfeit: http://rg.ancients.info/bogos

"Reid Goldsborough" wrote in message
...
The following will be an exercise of truth, and falsity, exposed, with
sources cited.

Good.

This is about whizzing, with the recent discussion about this until
now in a thread about ancient coins titled "Ancient Coins: How to
Start a Collection?" Whizzing, however, is primarily an issue
affecting modern coins, so I've broken out this new thread, labeling
it with a subject line that describes it.


Happy to switch threads and join in.


irrelevant insults snipped

...Jeff had done an experiment that purported showed
that when a coin is whizzed, metal isn't moved. My "ignorant" comment
was that when a coin is whizzed, metal does move. This is the main
point of contention. Does metal move, or not?

Good summary of the main point here.

(so far so good)


Now, Jeff said that he's a metal worker,

Implication: he's lying

...but he admitted that he has
never seen a whizzed coin, done by a real coin doctor. What's more,
he's got the physics all wrong, talking about how there's no rise in
temperature during whizzing caused by the fiction of the rotary wire
wheel against the metallic surface, that it's all room temperature,
even the point of contact, which defies even common sense.

Actually, Reid, you have mis-stated and misrepresented my point(again).
I restate:

The rise in temperature due to friction is small enough to be considered
irrelevant, and therefore the operation can be considered to take place at
room temperature.

Mo The rise in temperature required to cause a phase change in the parent
metal (read: "soften" it) is orders of magnitude greater than can be
achieved through the pressure of a spinning wire brush.

And again: Even if such a temperature was achievable, the metal in the tip
of the brush would undergo a similar phase change and would be effectively
destroyed.

Elaboration: The coin field represents a very efficient heatsink. An
enormous amount of highly directed and intense heat energy would be required
to soften the surface, whilst the rest of the bulk of the coin is rapidly
leaching the heat away. Remember that all coin metals are good conductors of
heat - some of them *excellent*, top-of-the-line conductors. A
pipette-style tiny jeweller's blowtorch tip could do this, but in a
relatively uncontrolled fashion.

Further: In the meantime the much smaller tips of the wirebrush (a poorer
conductor, if we're talking steel) will have heated up to a higher
temperature than the coin field, as a direct function of their much smaller
size and the fact that they are unremittingly in the path of the friction.
(The point of contact on the coin surface may well be moving.) The
air-cooling effect of the rotation, and the fact that they are only in
contact with the hot surface for, say, 30-40 degrees of rotation is
massively overwhelmed by the fact of their tiny cross-section.

(Put a thin wire in the flame of a blowtorch. Count the seconds until it
gets to red hot. You probably won't make it past "1". Do the same with a
coin. How long until its hot enough to "flow"? By comparison, ages.)

Thus: If heat was involved in this process, then the wire brush would
self-destruct long before sufficient heat had been generated in the coin
field to have any effect whatsoever. Heating a coin up a few tens of
degrees (hot enough to give you third degree burns) is not sufficient to
effect a phase change which will soften it. The best you'll do is
discolour/recolour the oxide layer - if you haven't stripped it off already.

Do these expert "coin doctors" have access to titanium or tungsten carbide
tipped wire brushes? I'd like to get hold of one of those.


...He this means me, Jeff R. made
further incorrect assumptions, saying that I based my conclusions on
the Internet when I hadn't even done a Google search about this and
when in actuality what I based my conclusions on was direct
observation of the results of what whizzers do.

Despite many references in this argument - even this post - to the Internet
research you've done. :-)

...Read on for citations,
showing how others have also come to the same conclusions (this will
be new information about this subject).

After Anka started things, others jumped in (this is Usenet g), some
agreeing with me, some agreeing with Jeff.

Phil agreed with Jeff, basing his proclamations on his working with
gemstones.

....and sterling silver, which you conveniently choose to ignore.

...That's a good one, isn't it? As usual, he otherwise acted
only as a disruptive troller who's in the discussion primarily to
interfere.

Disagreeing with RG doesn't necessarily constitute "disruptive trolling."
I object to the enthusiastic propagation of ignorant untruths. That's why I
participate in these threads.

I restate my challenge to RG: Kindly point out one single error I have made
of fact in physics or metallurgy (or whatever).

Yours are legion.


Tony didn't seem to know what he wanted to say. He believes the same
as I do -- he's got the physics right -- but he tied himself up in
knots to avoid having to admit he agreed with me.

That's how you interpreted that? Wow.


Others agreed with me, that metal moves.

To prove my proposition

Begging your pardon, RG, the following does no such thing. The burden of
proof is a good deal more onerous than that, and cannot be demonstrated
through casual discussion and expression of opinion.

...that metal moves, I shared my observations
(and those of many others) of how on a whizzed coin metal is bunched
up against legends and devices -- moved by the rotary wire wheel
through heat and force, causing it to behave like a thick liquid

Any metalworker or metallurgist or physicist will LOL at that absurd
proposition.
Heat and force, huh?

Heat: A wire brush cannot generate the heat required. See above.

Force: A wire brush is flexible and lightweight. To even suggest that it
operates in a manner even slightly analogous to a coin die in a press is
(words fail me... help me here Tony. I need a word that means f%$*ing
stupid, without actually resorting to vulgarity.)

Even when spinning at 30,000rpm, the point-contact force that a wire brush
can produce is trivial compared to that which is produced by a 50 tonne
press through a rigid, hardened-and-tempered tool steel die.

Spin up a wire brush on a Dremel. Place it gently on a surface. Now, press
down hard. It deflects! You can see this in the shape of the brush. A
brush cannot impart the force you are referring to.

... in
a very similar way that metal behaves when a coin is struck. I also
shared the fact that the weight of whizzed coins is the same as
unwhizzed coins. If metal were removed, not moved, the weight would be
less, and that would be a diagnostic.

Abrasion with a wire brush can (and does) remove a tiny amount of metal, in
order to do the required polishing. This would be well below the
margin-of-error of the mass of any coin. I challenge you to:

(1) weigh a coin
(2) polish it with a Dremel
(3) weigh it again
(4) note any difference

Of the five lab scales I own, only two are reliable to 0.01g. I bet I
couldn't reliably detect a difference. We're talking matter of scale here,
Reid. When I say "metal is removed" I don't necessarily mean "a lot of
metal is removed."

(This *can* be the case, as I'll mention later.)


...It's not. You could say "Duh!"
to all this and leave it alone, but the amateurs and the
self-appointed experts and the arguers continue to argue and argue and
argue against all reason. The best approach to false speech is more
speech, as U.S. Supreme Court Justice Louis Brandeis once said. So...

No - the best approach is to examine the evidence, understand the mechanics,
formulate a hypothesis, then seek to demonstrate (or, *better*) disprove
said hypothesis.

Cheesy quotes have no place in such a process.

This is from the book Official A.N.A. Grading Standards for United
States Coins: "A whizzed coin has been mechanically wire-brushed...
The most important diagnostic is the build-up of metal on the coin's
raised devices. As the wire brush moves across the surface of the
coin, a microscopic layer of metal is liquefied BY THE HEAT produced
by friction." (Emphasis mine.)

And error yours as well. This is simply not true. Even "microscopically"
such a process is fanciful.

...The ANA continues: "The metal is pushed
along in front of the brush until a raised device is encountered, upon
which a ridge of metal is deposited." Gee, sounds familiar, doesn't
it?

Well, yes, since it's your primary source.

Enough? Of course not. The arguers are going to keep on arguing, never
admitting they're wrong. They'll say, "Who's the ANA. They're not the
be-and-end-all. Do they have a metal shop like me? Who cares if their
conclusions are based on real-world coins, real-word observations,
real-world measurements. I know. I'm telling you all, I know. You must
believe me."

These folk are well-intentioned and presumably not intending to deliberately
mislead. They are wrong, 'though.

They are numismatists, not (I presume) metallurgists. They have made an
observation (the appearance of a whizzed coin) and have concocted a fanciful
explanation for the mechanics of the process. I defer to their numismatic
skills. (I can't distinguish between an MS62 and an MS64 to save my life.) I
don't defer to their metallurgical experience. Their explanation *sounds*
(to the amateur) plausible and comfortable. Therefore it enters numismatic
folklore as "fact"... until someone seeks to challenge it.

Yes, Reid, they're wrong.
There is a better explanation for the process, which I'll outline below.
Less romantic, but much less fanciful.


OK. Here's another source, PCGS. This is from its book Official Guide
to Coin Grading and Counterfeit Detection: "Whizzing is a technique in
which surface metal is MOVED mechanically to create the illusion of
luster." (Emphasis mine.)

Sigghhh.
If you had bothered to look, Reid, this is the very source which prompted me
to produce my whizzing webpage referred to earlier.
http://www.mendosus.com/whizzing/whiz.html
Please note the *very first* paragraph on that page of mine. I'm not afraid
of your source, just because of his (their?) iconic status in the
coin-grading industry. It was (actually) my disappointment with PCGS - that
they would publish and endorse such rubbish - which motivated my discourse.

...PCGS then goes on to describe newer methods
used primarily with proof coins that support some of the speculations
made here by Tony that involve, along with a rotary brush, additional
heat and/or chemicals or heat alone, but the diagnostics for these new
methods are different from conventional whizzing -- the surfaces look
plated/chromed or are wavy.

As Phil pointed out, chemicals "dissolve", not "soften". Please refer me to
any chemical which you know of which will "soften" the surface of a coin,
sufficiently to allow its physical alteration by mechanical methods.

Of course, chemical etching can be used to alter a surface, but that is a
totally different process. I would have said a "red herring", but I'm still
smarting. How about: an interesting side-branch, or offshoot, of the
whizzing argument. Not pertinent to the "wire brush makes coin metal move
plastically" argument, 'though.



Now, the arguers will no doubt also fault PCGS, saying something like,
"Who's PCGS. They're American. How many coins have they seen? Do they
have a metal shop? Have they done an experiment and put up the results
on the Web? What do they know. I know. I'm telling you."

Well, thanks for pre-supposing what I'll say. Have I *ever* used nationality
as a measure of technical expertise, Mr Straw-Man?


I'm neglecting to mention other speciousness that no doubt will follow
this: Nitpicking nonsense that ignores the core issue here (metal
moving),

I keep on repeating, and you keep on ignoring my challenge; so here goes
again:

"How can a flexible wire brush cause plastic deformation on the surface of a
coin?"

You have failed to address this question in every post.

... talking in tongues,

What?

...obfuscating language to hide having to
agree,

One example, please Reid. Just one. Of my "obfuscating" language. One only
required. I have tried to be as clear as possible. Any jargon I've
employed (e.g. "plastic deformation") I have used because there is no other
satisfactory term. Beside which, you can always Google anything you don't
understand. Again.

...accusations and outright flaming

I've tried *very* hard to address the issue, not the man. You should look
to your own record in this regard.


...to divert the discussion away
from the core issue (metal moving), all the rest. Nobody will admit
they were wrong.

Bottom line: Metal is moved.

"How can a flexible wire brush cause plastic deformation on the surface of a
coin?"

... Not removed. With whizzing. Just as with
striking.

OK. Let's hope the analogy police don't see this one:

Your comparison of whizzing to striking is like comparing sweeping the
leaves off a concrete driveway with breaking up the same concrete with a
pneumatic hammer.


Hah! Sorry. I couldn't resist. This was just so much fun. And maybe,
just maybe, somebody ... or many people ... reading this learned
something interesting about coins.

Glad you're enjoying it.

Now please explain how a wire brush can develop sufficient force and/or
temperature gain to liquify the surface of a coin.

Include as many cites as you like.

(BTW, the above is much more difficult challenge than my usual "produce
plastic deformation" challenge, but he insists on making the liquify claim,
so...)

============================================
The Issue of Ridges and Crests Near Devices.
============================================

I actually covered this briefly four years ago, and this diagram may help
new-comers: http://www.mendosus.com/whizzing/gif/ridges-2.gif

This shows the production of "ridges" through abrasion. It is deliberately a
gross exaggeration of the effect, with the intent of making the process easy
to understand.

In actual effect, the whizzer would polish off and shine up the surface of
the coin, and attempt to introduce artificial lustre marks by controlling
the
direction of the passage of the brush. The amount of metal removed would be
minimal - certainly not measurable outside the controlled atmosphere of a
lab.

When the whizzer approaches a device on the surface, he naturally backs off,
since the wire brush would quickly obliterate detail on raised device. Thus,
the field around the device is whizzed - maybe savagely. The device is not
(usually). In-between the two, at the junction of the device and the field
(or, "up against the edge of the device) there may well be ridges that have
been *carved*, not "raised" from the base metal.

Here we are talking measures in order of 0.01mm or so (a few thou', for the
oldies here). Short of employing extraordinarily precise measuring devices,
it would be practically impossible to distinguish between ridges produced by
raising metal, and ridges produced by removing metal.

You can't see where the original surface level was, after its been polished
off.

The very sides of the devices could easily exhibit such abraded ridges,
whilst giving the appearance of "raised" or "moved" metal.

This image: http://www.mendosus.com/whizzing/gif/cross-section.gif
demonstrates what happens when you attempt to produce sufficient
heat/friction to actually *move* metal. The LHS depicts the unwhizzed
surface, the RHS shows the savagely whizzed section.

The red line depicts the original level of the field.

See all the new ridges? Were they raised? No. They were carved. When you
look at the section which features ridges, (in real life, under a
microscope) could you
reasonably conclude that the ridges were somehow "raised"? Well, yes,
maybe. It would be easy to be fooled. (Although this was an unapologetically
savage attempt.) Further observation shows they were carved.

My example is a savage and heavy-handed demonstration. (Still couldn't
liquify the metal, 'though.) An accomplished "coin doctor" would, of
course, be more subtle. They still wouldn't be able to "move" metal,
'though. The effect would be the same, though muted. No liquefaction
required.

=======
Finally
=======

I would be delighted to be proven wrong.

By anyone.

Please - can someone outline a process whereby a wire brush can produce
sufficient heat and/or force to partially liquify the surface of a coin, and
then move that liquified metal around the surface of the coin?

Anyone?

Hellooooo......

Anybody there......?

--
Jeff R.

wrote in message
ups.com...
We made an exhibit at my old store about ten years ago of sample
silver Washington quarters which had been artificially toned,
overdipped, cleaned with baking soda, metal polish, an eraser,
cloroxed, thumbed, and whizzed, along with brilliant Unc and several
naturally toned Unc examples. I gave one of the coins a real work
over with a wire brush on Dremmel. Picked it up to look at it and
burned the crap out of myself. Had a red spot on my fingers that took
2 weeks to go away. So I can believe the surface layer got hot enough
to liquify.


Oh, cut it out, Frank.

You can get third degree burns, from temperatures well under 100 deg C.
Coin metal isn't even touched by such mild warmth.

Sure it can get hot enough to burn you. We mammals are pretty sensitive,
y'know.
Work-hardened metal is a bit tougher than that.

(Try this test: Boil up some water in a silver container. Keep it boiling.
Is the silver affected? Now plunge your finger in the boiling water and
count slowly to ten.)

--
Jeff R.
(Note to kiddies: Please don't do the above test.)

"Reid Goldsborough" wrote in message
...
On Sun, 30 Sep 2007 12:05:04 -0700, Phil DeMayo
wrote:

Oh, is that what it is?

You just proved my point. One of them. You're here just to argue. You,
and people like you -- and there seems to be a disproportionate
percentage of them online -- never, ever, ever admit it when you're
wrong. You never have, not once, in any conversation I've ever
observed. Same with a few of the others. And when some of them do
admit they're wrong, it's coached in language so as not to make it
seem that they're admitting they're wrong.

This of course is an issue separate from how metal moves on a planchet
or a coin's surface, an issue involving online communication in
general and psychology online and offline.
...


Oh, spare us the pop-psych bullsh.

Just answer the question posed over and over again:

"How can a wire brush produce sufficient force (and/or heat) to cause
plastic flow (or *liquefaction*, for heaven's sake) in the surface of a
coin."

Stop avoiding the question.
Stop insulting and belittling.
Stop misquoting and straw-manning.

Just answer the question...

--
Jeff R.

"tony cooper" wrote in message
...

I'll snip the rest of your fustian ramble.
--


Tony Cooper
Orlando, FL


"Fustian ramble"

There's a keeper. Thanks Tony. :-)

--
Jeff R.
(I love this NG)

"RF" wrote in message
ps.com...
On Sep 30, 4:06 pm, Reid Goldsborough
wrote:
On Sun, 30 Sep 2007 12:05:04 -0700, Phil DeMayo
wrote:

Oh, is that what it is?


snip lots of fustian rambling


Jeez, what a pedantic windbag you are!

Ha! You ain't seen nuffink yet.
(Have a look at my 17kb response!)

--
Jeff R.
(Je Ne Regrette Rien)

"Reid Goldsborough" wrote in message
...


... I hadn't heard before the term
"metal chasing." Interesting. A very quick Google search indicates it
has legitimate metallurgical functions as well.

"As well"?

Very generous of you.

All the junior metalworkers in my classes complete a chased (and planished)
copper candlestick bowl as one of their first prac projects. They love,
largely because of the noise they're allowed to make - *have* to make!

When they leave me at the end of term, I *always* test their vocabulary
retention. Nearly all of them remember the terms "chasing" and "planishing"
and "repousse" and "work hardening" and "annealing" and "copper" and "brass"
and "alloy" and (and so on...)

Different education systems, different results, I guess.

I keep forgetting how little some people know.

--
Jeff R.
(then I am reminded)

"Reid Goldsborough" wrote in message
...
...and the authors of the
PCGS guide by simply looking under a stereo microscope at a whizzed
coin. Try it, you'll like it. Under such magnification the surfaces of
untooled coins also reveal wonders unseen and unseeable by the naked
eye. Different world, with cliffs and valleys like some alien
landscape.

I *do* hope you're not implying here that the rest of us aren't familiar
with the joys of microscopy.

Just discovered it, did you?

--
Jeff R.

"Reid Goldsborough" wrote in message
...
On Sun, 30 Sep 2007 16:45:57 -0700, Anka wrote:

Only in your own little universe.

See, this kind of comment leaves me scratching my head. You're an
intelligent person. Yet you're acting the opposite. You accused me of
offering up numerous ignorant comments, yet you quoted one in which I
agreed with the authors of the two most widely used and respected
grading guides in the coin industry. Were their comments ignorant too?


Yup.

RG (paraphrased): "You can melt coin metal with a wire brush."

Do you deny that statement, paraphrased as it is?

If so, then restate its intent in a way in which you are comfortable. Then
defend it.

If no, then attempt to justify it, from a real-world metallurgical point of
view.

It is an example of colossal ignorance.

--
Jeff R.