Stupid question of the day....

[John Fields]

You're an idiot.


Wrong. The result is corrosion. The activity is called "reaction".

Your favorite web site which you posted a reference to speaks about
the end result.

---
Right. That's what the topic is about: galvanic corrosion, and
which is what all of us, except you, have been talking about.
---

The moniker I gave speaks about the process itself.

---
Crappola. You know nothing about the process, and when you butted
in with your shit, and with what you think the Navy thinks, you
thought that "galvanic action" was the right name for what it's
called. It's not, and now you're trying to cover your ass by doing
a little semantic "shuffle and smoke" routine. Typical for you, you
phony piece of shit. I suspect next you'll be off searching the web
for every possible thing you can find on galvanic corrosion just to
make it seem like, the next time you post, you knew it beforehand.
Hey, I'll even _give_ you a hand. Google "electrochemical series"
and suck on that for a while.
---

You're a fucking jackass. Everybody speaks about that.

---
Make a list, motherfucker.
---

Two more reasons you should be on everyone's filtered list.

---
Because you knew nothing about it and couldn't manage to pull your
head out of your ass? Sounds to me more like reasons for folks to
plonk _your_ sorry ass out of existence.
---

I commented on how much of an asshole you are. When I say
something, you come back demanding proofs, yet you get to make a
jackjawed remark like "not true" and think you won't see anything said
about how much of an ass you are? Sorry, CHUMP! You don't get that.

---
The reason I demand proofs from you is because you're a fucking
liar.

I'm not, and when I say that something isn't true I can back it up
even if I don't choose to at the time I said it, for whatever
reason. The last one had to do with the poster's carelessness in
not declaring that an electrolyte was needed in order for galvanic
corrosion to proceed, and I figured that if I gave him a little prod
he'd figure it out for himself. I was a little surprised that he
was miffed at not having been given the answer on a silver platter,
but there ya go...

See, Tokey, one of the differences between you and I is that I've
got a solid technical background and can stand my ground without
having to resort to bullshit tactics, like you do, in order to try
to blow up my balloon.
---

 

[Bob Myers]

No. What the figure tells one is where the current is near zero,

Not at all. You're apparently using a very interesting, albeit
incorrect, definition of "skin depth." As has already been pointed
out numerous times, the "skin depth" figure that results from the
calculations you've been using is where the current density is
down to about 37% of its "surface" value (not 37% of the conductance
or loss or any other nonsensical notion that you seemed to think
in a previous post). There is clearly still current farther from
the surface than the "skin depth," and it is also clear that the
density above that value is non-uniform. This IS important,
and again I would suggest you check the values through an
actual loss calculation to see just how big the effect can be.

Try being less stupid. THAT is what is unwarranted here. Unless,
of course, it just comes naturally for you.

That comment is particularly ironic, along with:

More stupidity. That was merely one location that I pointed out.
It explains it quite well, however, and much better than your
insulting ass does.

given the following:

You might get along with folks, if you stop with the bullshit
insults. Sorry if YOU don't see your remarks that way, but I know
better. Both about the remarks, and the topic.

Talk about the pot complaining about the complexion of the
kettle...

Further nonsense:

Pure aluminum or pure copper runs will see no difference.

Translation: you didn't bother to run the numbers, or you wouldn't
be saying something so obviously incorrect. Next time, show your
work.

Bob M.

 

[Don Klipstein]

No shit.


Your application of your "math" is what needs a second look.


What part of "you did the math wrong" do you not understand?

Before it would make a difference, the wire will have to be pretty
big (over 17mm diameter) , and before it will make a 37% difference,
it would have to be bigger still! Real simple math, there.

Ratio of AC resistance at 60 Hz to DC resistance for 17 mm diameter
copper wire:

Going by "High Frequency Resistance", pages 3323-3325 of the 43rd
edition of the "CRC Handbook":

They give a formula X=pi*d*SQR((2*u*f)/rho)*SQR(1000)

u is magnetic permeability, unity for copper.

rho is resistivity in microohm-cm.

They simplify this for copper, to x=10*d*.01071SQR(f)

d is diameter in centimeters, and f is frequency in Hz.

So, for 17 mm diameter copper wire at 60 Hz this "x" is 1.41.

Next is a table that gives ratio of AC resistance to DC resistance as a
function of this "x".

This table has an entry for 1.4, giving AC resistance 1.020 times DC
resistance.

- Don Klipstein ([email protected])

 

[John Fields]

And that be you. Your method is wrong, and wrong is wrong.

You're fucked John. No way out.

 

[Bob Myers]

Look up Galvanic reaction in ship hulls, and you will find that all
Navy ships have provisions to reduce it.

But that wasn't the question. You were responding to a comment made
in the specific context of gold-on-copper, to the effect that "galvanic
reaction" was the reason that such a combination wasn't a good idea.
Sorry, but the "galvanic reaction" of dissimilar metals has absolutely
nothing to do with the subject at hand.

There actually very often IS another layer (commonly, nickel) placed
between a copper conductor and a top protective layer of gold, but
this has nothing whatsoever to do with a "galvanic reaction" between
these two metals. (If it did, following the original incorrect response
on this subject, the problem would then become WORSE due to the
fact that there would now be two such interfaces rather than one.
Remember, if you can, that the original comment along these lines said
that a "galvanic reaction" was a problem between ANY two metals.)
The reason that an intermediate layer of nickel is often used in this
case has to do with the fact that, left to themselves, gold and copper
will tend to diffuse into one another. This causes a problem in
electrical applications (where gold-plating copper conductors is being
done to prevent corrosion) primarily on the gold side of things, as
the copper diffusing up through the gold layer will eventually reach
the surface and create the very same corrosion problem that the gold
was supposed to be preventing. Nickel doesn't diffuse into gold
like copper does, hence its use here.

Note again that my reference is to the effect, not the remarks about
specific elements. Learn to read.

My, again with the personal attacks; I suppose in the absence of
practical knowledge, that's about all one is left with.

Bob M.

 

[TokaMundo]

That depends on one's definition of 'nil' I guess.


Not quite. If by 'heat the wire evenly', you mean heat is generated equally
in each unit of cross-section, yes. Since the resistivity of the material
is a constant, and if the current density is uniform throughout, then the
amount of I^2R losses in each unit cross-section is the same. But the
material in the center will be a higher *temperature* than that around the
periphery. It's simple really, the heat generated in the center must be
conducted to the circle of material surrounding it. The heat from the
center, combined with the heat generated in the circle of material must now
be conducted to the next circle of material surrounding that. And so on...
So the material just under the surface has heat generated directly in it,
*PLUS* all the heat generated in interior material conducted into it. For
uniform heat generation throughout the material, it is simple integration to
show that the temperature profile is a parabolic with the apex at the
centerline and temperature falling off as one moves further from the center
to the outer surface.

So the *temperature* profile throughout the conductor is far from 'even'.
If the material has a positive temperature coefficient of resistivity (as do
both copper and Al), then the resistence of the central core is higher than
the outer surface. The exact amount of temperature difference is a function
of the electrical resistivity and thermal conductance of the material.

daestrom

Since a thin round copper wire has a very low emissivity it wont
give up its heat all that fast. This will mean that your thermal
gradient won't be as prevalent as you suggest. The proof is when one
takes a copper wire and places it across a battery's terminals.
Notice how the entire wire turns a nice cherry red quite evenly, all
the way up to where it is attached to any form of sinking element.

The current throughout the wire will be even, and it is that current
which generates the heat, or more precisely, the resistance to said
current flow.

If the wire were giving up its heat real fast, like that of a finned
heat sink with air passing over it, I might agree. In the case of
bare copper, however, the temperature throughout the wire is going to
be very even. Your gradient will be nearly undetectable.

For a very large diameter copper bus, it MIGHT have a slight
gradient between the center and the outer surface, but not much. For
wire, it is as even as even gets.

 

[TokaMundo]

The Navy knows it's a problem, but then naval ships are in seawater. One
must have an electrolyte to complete the 'circuit'. This is one reason why
commercial work with Al conductors often requires the application of special
'grease' to seal the connection from moisture intrusion.

Actually, it is an oxide inhibitor, and its function is to seal away
oxygen.

It too is conductive.

 

[TokaMundo]

Bullshit. My reference to the Navy being concerned with it proves
that you are yet again, just being an ass. I see that that is easy
for you though.

Galvanic reaction IS the process by which galvanic corrosion occurs.
Try using facts, asshole.

You know nothing about the process,

Sure I do.

and when you butted
in with your shit,

I didn't butt in, asshole. I called you an idiot, because your
response was nothing less than idiocy.

and with what you think the Navy thinks,

It is more like what I know that the Navy thinks, asshole.

you
thought that "galvanic action"

I never said that, idiot old man. What I said was REACTION.
Big difference.

was the right name for what it's
called.

I never said that term, so you are yet again an ass.

It's not, and now you're trying to cover your ass by doing
a little semantic "shuffle and smoke" routine.

You're full of shit. No semantics about Johnny. You are a piece of
shit, therefore you must consist of nothing but shit. So far, in this
thread, you have proven that beyond all doubt.

Typical for you, you
phony piece of shit.

More proof. Do you have any facts to contribute, asswipe?

I suspect next you'll be off searching the web
for every possible thing you can find on galvanic corrosion just to
make it seem like, the next time you post, you knew it beforehand.

I have been around more ships than your lard ass has.

Hey, I'll even _give_ you a hand. Google "electrochemical series"
and suck on that for a while.

**** off, and die. Suck on that forever.

Mirror, mirror, little boy.

Everybody speaks about that.

Hahahaha... everyone jumped on me ONLY because I called you the
asshole that you are. They would quickly learn how right I am by
merely looking at your posting history. Particularly those posts
where you are an insulting twit, which is quite often.

You're an idiot that hides behind the fact that you are beyond arm's
reach, boy.

No. The fact that you are the fucking troll, boy.

Sounds to me more like reasons for folks to
plonk _your_ sorry ass out of existence.

I could give a shit what others do, but I don't.
You're a fucking retard. One that is lucky he is beyond arm's
reach.

I'm not,

Yes, you are. You are exactly that.

and when I say that something isn't true

You called me a liar, and you can't back up a fucking thing, retard
boy.

I can back it up
even if I don't choose to at the time I said it,

You are the same retarded twit that demands that others do what you
feel you have a right to choose to ignore doing. Precious!

for whatever
reason.

Like being a mere insulting asswipe?

The last one had to do with the poster's carelessness in
not declaring that an electrolyte was needed in order for galvanic
corrosion to proceed,

It's not for you to declare someone else to be careless, and then
justify your own carelessness. Especially when you frame it as an
insult, which you invariably do.

and I figured that if I gave him a little prod

You mean like the one I gave you for your spell checker retarded
behavior?

he'd figure it out for himself. I was a little surprised that he
was miffed at not having been given the answer on a silver platter,
but there ya go...

I wish you'd go. Straight to hell, dipshit.

See, Tokey,

**** you, asshole. Your bullshit enlightens no one.

one of the differences between you and I is

That you are a fat, old lardass that is near death, and feels the
need to "prod" folks. **** off, asshole.

that I've
got a solid technical background

No. You are shit. You aren't even technician grade, and you copy
most if not all of the circuits which YOU claim to have designed.

and can stand my ground without
having to resort to bullshit tactics,

If only you were within arm's reach, I would prove you so wrong.

like you do, in order to try
to blow up my balloon.

Your ballooned ass is already blown up.... real good...


You're an idiot. Just like I said.

Tokamundo? More like Tokanada.

You're also retarded. Seek help, asshole.

 

[TokaMundo]

Translation: you didn't bother to run the numbers, or you wouldn't
be saying something so obviously incorrect. Next time, show your
work.

Hey Bobby... **** you. Filter me like you have already claimed to
do, you petty asswipe.

 

[Repeating Rifle]

Some people say that there is no such thing as a stupid question. Obviously
there seems to be no shortage of stupid answers.

Bill

 

[TokaMundo]

Going by "High Frequency Resistance", pages 3323-3325 of the 43rd
edition of the "CRC Handbook":

They give a formula X=pi*d*SQR((2*u*f)/rho)*SQR(1000)

u is magnetic permeability, unity for copper.

rho is resistivity in microohm-cm.

They simplify this for copper, to x=10*d*.01071SQR(f)

d is diameter in centimeters, and f is frequency in Hz.

So, for 17 mm diameter copper wire at 60 Hz this "x" is 1.41.

Next is a table that gives ratio of AC resistance to DC resistance as a
function of this "x".

This table has an entry for 1.4, giving AC resistance 1.020 times DC
resistance.

The table I saw shows the AC and DC resistance as being exactly the
same for both.

Your flaw is where you failed to note the topic given in the CRC
handbook.

60 Hz is NOT high frequency... at all.

Try some calculations at 100 kHz and you'll see that those
frequencies down near zero (ie 60Hz) yield very nearly nil difference.

 

[TokaMundo]

My, again with the personal attacks; I suppose in the absence of
practical knowledge, that's about all one is left with.

As if declaring that someone has "no practical knowledge" isn't a
personal attack.

**** off retard. You have social problems.

 

[TokaMundo]

Some people say that there is no such thing as a stupid question. Obviously
there seems to be no shortage of stupid answers.

Bill

Yours certainly contributed absofuckinglutely nothing, and would
certainly fall into the "stupid answer" category.

You remind me of a Firesign Theatre quote:

"Who wona second world war.. you so smart?"

Perhaps, if you are so informed, you should try giving an answer
that actually has facts in it that are in sync with the topic of the
thread, not merely its title.

 

[John Popelish]

It's called galvanic reaction.

The Navy seems to think it's real. Does that make you an idiot?

The Navy also deals with lots of salt water. ;-)

 

[John Larkin]

Some people say that there is no such thing as a stupid question. Obviously
there seems to be no shortage of stupid answers.

Bill

There are no stupid questions, only stupid people.

John

 

[Don Klipstein]

The table I saw shows the AC and DC resistance as being exactly the
same for both.

Maybe your table rounds? Please cite source as well as I did.

Your flaw is where you failed to note the topic given in the CRC
handbook.

I did note this, as you quoted above.

60 Hz is NOT high frequency... at all.

Try some calculations at 100 kHz and you'll see that those
frequencies down near zero (ie 60Hz) yield very nearly nil difference.

The formulas are functions of wire diameter, wire resistivity and
frequency, and do not lose validity merely because a thick wire has AC
resistance greater than DC resistance at a frequency that is easy to label
"NOT high".

And as you asked... Ratio of AC resistance to DC resistance of 17 mm
diameter copper wire at 100 KHz is about 21.5. This does not invalidate
the calculation for 60 Hz.

You would have been better off claiming that resistance 2% higher at 60
Hz than at DC is a negligible increase.

- Don Klipstein ([email protected])

 

[Autymn D. C.]

I see. Instead of reason, you prefer insult.

I will neither read your "proof" nor will I shut up, and if you
don't like it, you miserable son of a bitch, you can go ****
yourself.

I'm not a son, you illiterate and uncouth obscurantist troll. I
already used reason in the proof, which you wilfully ignore. It uses
maths too, which puts a limiting case on the Lorentz corrections,
remembering that GR and QM are incompatible. It looks like my other
replier didn't read it too or he would be forced to agree with me. The
people here are retards.

-Aut

 

[Autymn D. C.]

There are no stupid questions, only stupid people.

There are stupid questions, those that could be easily found on one's
own.

 

[Autymn D. C.]

Stop swearing or I'll beat your head in, the part that causes swearing.

 

[Autymn D. C.]

I looked at it, and you're right, the posting at that URL is wrong.
here's another time wasting URL http://www.geocities.com/jasen_betts/Autymn.txt

You can't prove anything. You're wrong in everything.