I have noticed recently that any exposed copper in my shop has a black,
burnt look to it.

What is causing this? I first noticed it in my electrical panel, and
thought I must have really overheated that circuit. Then I noticed it
on the exposed ends of some scrap wiring I had around, so I concluded
that wasnt' the case.

This is more than the usual oxidation that occurs over time on copper.
Peeling back the insulation on said scraps of solid wiring, the first
inch will have the discoloration, and the rest will still be the nice
shiny wire.

Explanations? I assume a result of some cleaner or something I used,
but wondering what.....

Thanks

JW

ammonia? chlorine?

"jw" wrote in message
ups.com...
I have noticed recently that any exposed copper in my shop has a black,
burnt look to it.

What is causing this? I first noticed it in my electrical panel, and
thought I must have really overheated that circuit. Then I noticed it
on the exposed ends of some scrap wiring I had around, so I concluded
that wasnt' the case.

This is more than the usual oxidation that occurs over time on copper.
Peeling back the insulation on said scraps of solid wiring, the first
inch will have the discoloration, and the rest will still be the nice
shiny wire.

Explanations? I assume a result of some cleaner or something I used,
but wondering what.....

Thanks

JW

"jw" wrote in message
ups.com...
I have noticed recently that any exposed copper in my shop has a black,
burnt look to it.

What is causing this? I first noticed it in my electrical panel, and
thought I must have really overheated that circuit. Then I noticed it
on the exposed ends of some scrap wiring I had around, so I concluded
that wasnt' the case.

I know exactly what it is, but not necessarily where it's coming from.

The culprit is H2S - hydrogen sulfide gas. The source???? Who knows. You
do.

Are you on a private well for water? Do you have sulfur water? In or even
NEAR your shop will suffice.
Do you work with highly sulfured oil in a small shop? That'll do it. (*but
not unless you're actually cutting with - heating - it)
Do you have anything proteinous rotting around there (lotta shops have a
dead rat in the wall) ? That'll do it.
How-bout black powder arms and/or powder stored in your shop? *that's a bad
source of it*
Have you had a spill of, say, a gun bluing fluid in there?
Gas leaks? (some H2S in natural gas). Leaking mixed-gas (LP is sometimes
not propane, but a mix of propane, butane, and natural gas with its H2S
component.)

HCl fumes (hydrogen chloride) can do it more slowly. Have you been
machining lots of PVC? That'll do it.

A few ideas.
LLoyd

On 16 Jun 2005 08:30:24 -0700, the renowned "jw"
wrote:

I have noticed recently that any exposed copper in my shop has a black,
burnt look to it.

What is causing this? I first noticed it in my electrical panel, and
thought I must have really overheated that circuit. Then I noticed it
on the exposed ends of some scrap wiring I had around, so I concluded
that wasnt' the case.

This is more than the usual oxidation that occurs over time on copper.
Peeling back the insulation on said scraps of solid wiring, the first
inch will have the discoloration, and the rest will still be the nice
shiny wire.

Explanations? I assume a result of some cleaner or something I used,
but wondering what.....

Thanks

JW

Sulphur, maybe.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Spehro Pefhany wrote:


Sulphur, maybe.

Excessive flatulance?

Don't laff. I had a student job in a place where special purpose CRTs
were being made. The gun assemblies were mini-spot welded together in a
small clean room. They traced poor performance of the cathodes in some
CRTs to one assembler who pharted a lot when working there alone. The
H2S he emitted poisoned the surfaces of the cathodes.

I also remember hearing that certain employees at watch factories got
reputations as "rusters" because their skin moisture was much more
corrosive than average, and somewhat similar tales about women
assemblers who were ok in that regard save for a short period once each
month.

Jeff
--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

On 16 Jun 2005 16:54:29 GMT, Ignoramus30160
wrote:

On Thu, 16 Jun 2005 12:15:00 -0400, Jeff Wisnia wrote:
I also remember hearing that certain employees at watch factories got
reputations as "rusters" because their skin moisture was much more
corrosive than average, and somewhat similar tales about women
assemblers who were ok in that regard save for a short period once each
month.

I also wanted to suggest farting, but thought that it would be too
much after recommending a fart driven internal combustion engine
recently.

As for corrosive skin, my own fingers used to have this effect: steel
objects would rust where my fingerprints were, right on the
fingerprint line.

i

I have a shooting friend that only owns stainless steel weapons for
that same reason. Whenever he comes over, after handling a blued
steel firearm, I make a habit of wiping it down with solvent/lube
because he will leave rust spots behind.

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

Ah ha. Probably a result of the overcharged battery a while back.
!@$@%#$ timer stuck on the edge of off. I usually go check to make
sure, one time I didn't......

Every time since then it has also shut off properly on it' own.

I knew it was some sort of chemical reaction, but chemistry
wasn't(isn't) one my strong suits.

Thanks guys.

JW

Ignoramus30160 wrote:


I also wanted to suggest farting, but thought that it would be too
much after recommending a fart driven internal combustion engine
recently.


Might make for a bizarre external combustion engine though.

I attended the last New England Model Engineering Society's show and
amidst the ubiquitous steam and Sterling engine models I found an engine
type I'd never heard about before.

It looked like just another single cylinder horizontal steam engine, but
there was a hole in the middle of the head which was valved by a
pivoting shutter blade timed off the crankshaft.

A small alcohol burner was positioned so that its flame was adjacent to
that valve. The valve pivoted open when the piston was moving away from
TDC, sucking hot gases into the cylinder.

The valve closed near BDC and the gases cooled and developed a negative
pressure so the atmospheric pressure on the back of the piston pushed it
back towards TDC.

It was spinning away like mad, and the proud builder described it as an
"atmospheric" engine. The only atmospheric engines I'd heard about
before used condensing steam in a similar fashion, but seeing one
running by sucking flame directly into the cylinder like that was a gas.

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

"Jeff Wisnia" wrote in message
...
Spehro Pefhany wrote:


Sulphur, maybe.

Excessive flatulance?

Don't laff.


Oh! ,damn. I spent $30/gallon and another $50 for HASMAT fees for some
liquid that does just that. ;-)

Larry
--
Columbia, MO
www.llhote.com

Lloyd E. Sponenburgh wrote:

The culprit is H2S - hydrogen sulfide gas. The source???? Who knows. You
do.

Too much farting?


Ni-SCNR-ck

--
Motormodelle / Engine Models
http://www.motor-manufaktur.de
todays SPAMfeed: 

Jeff Wisnia wrote:

A small alcohol burner was positioned so that its flame was adjacent to
that valve. The valve pivoted open when the piston was moving away from
TDC, sucking hot gases into the cylinder.

You call this engine-type "flame licker". We call it "flame eater".
A more sophisticated name is "vacuum engine".
Yes, they run very fast, but have no power at all. Their overall
efficency is about 0,5%.


Nick
--
Motormodelle / Engine Models
http://www.motor-manufaktur.de
todays SPAMfeed: 

jw wrote:

I have noticed recently that any exposed copper in my shop has a black,
burnt look to it.

What is causing this? I first noticed it in my electrical panel, and
thought I must have really overheated that circuit. Then I noticed it
on the exposed ends of some scrap wiring I had around, so I concluded
that wasnt' the case.

This is more than the usual oxidation that occurs over time on copper.
Peeling back the insulation on said scraps of solid wiring, the first
inch will have the discoloration, and the rest will still be the nice
shiny wire.

Explanations? I assume a result of some cleaner or something I used,
but wondering what.....

Thanks

JW

Is it an OZONE issue or Sulfur issue. Are there currents in effect across
the surface or do you live near a body of water or swamp ?

Martin

--
Martin Eastburn
@ home at Lion's Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

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Lloyd E. Sponenburgh wrote:

The culprit is H2S - hydrogen sulfide gas. The source???? Who knows.
You
do.


BTW... when I said that "HCl" can do it, too, I should have noted that
chloride corrosion on copper can vary in color from a dark earthen brown to
blue. But the black layer you saw is almost certainly from H2S.

LLoyd

Some of it, does have a bluish tint to it as well.

In either case, it seems that it can be linked to the overcharged
battery.

I assume that this is not a "real" problem? Any existing wiring should
not have developed extra resistance at the contact points. Any new
stuff, will of course get cleaned(if needed).

Thanks

JW

"jw" wrote in message
oups.com...
Some of it, does have a bluish tint to it as well.

In either case, it seems that it can be linked to the overcharged
battery.

I assume that this is not a "real" problem? Any existing wiring should
not have developed extra resistance at the contact points. Any new
stuff, will of course get cleaned(if needed).


Well, yes, and no. IF your connections were all perfectly tight, then the
interface area will be "gas tight", and no corrosion should have intruded
(at least very far) into the connections. If you suspect any of them were
the least bit under-torqued, you better check them, and clean any suspect
areas.

I had the same thing happen. My son turned my automatic charger to "manual"
because, "it wasn't charging fast enough, Dad!" Needless to say, it boiled
the battery dry before I discovered it. And yes, it corroded everything in
the room.

LLoyd

I had a sheet of copper laying on the bench, and suffering from FFS
(first flat surface) tendancies on some occassion, it had stuff laying
on top of it. You can now see a perfect outline of everything that was
on top of it. Doubting those contacts were "gas tight", I suspect I am
ok.

But, to be "better safe than sorry" I will make it a high priority to
check and retorque all of my electrical connections.

Thanks

JW