Today, a friend called me who was doing a project. They had a copper coated
steel rod about 5/8" dia. that was to be used as a ground rod for
electrical. They had no means of bending it, as it had to make a couple of
three doglegs to get around concrete. I told him that heating it would melt
the copper, and did not know if the inspector would pass it with the copper
gone. He said that was what the inspector told him to do. We'll see. If
it works, okay, if it doesn't, I'll set up a jig and bend it cold.
Now to the point. As I heated the copper, I noticed a beautiful color
change. Like peacock colors. Would it be possible to dissolve copper into
a solution, possibly using acid or electrolysis, then have the copper be
deposited on metal sheeting so that it could be heated again to get the
iridescent hues?
I've read a lot about electrolytic removal of rust, and it seems pretty
straightforward. This would be (?) a two step process. I'm going to Google
up on it. Anyone ever try it?
Steve
The solution is copper sulphate (as strong as it will go), with a drop
of acid added. Anode can be any clean scrap copper (I used bits of
pipe). If plating on iron/steel, watch out, as copper will naturally
displace iron, without applying any current. Unfortunately, the
resulting copper coating is usually weak. If you can survive that, use a
low, steady current (trial & error, or there are tables), to put on the
copper.
I once rebuilt a worn brass shaft this way, having nothing else. Plated
it up with copper, then trued in the lathe.
In your case, could you heat/bend the rod as needed, then re-plate it?
Usually done right on the job with a 1/2" "hickey bender". That is a manual
bender for 1/2" rigid conduit. Most construction electricians will have one on
their truck somewhere.
Vaughn
You would need a Solution 20-25% of Hydrofluoric acid (Nasty Stuff) 50%
Nitric acid, and 20-40 Volt, 1 Amp power supply.
Depending on time and current, you can get a nice copper coating on any
surface.
Google Hydrofluoric acid before you even try it. Not something you want to
get on any part of your body.
As Simon says, go with cold forming.
Jim
Rather than attempting the improbable you can get the iridescence by
passivating the copper deposited on your material.This involves a short
dip in a dilute chromic solution Potassium Dichromate is a good
candidate and you can get a similar effect on bright zinc it is a
process used to reduce the reactivity of the surface layer of
electroplated materials. If my memory serves we used to
derust electrolitically using a sodium hydroxide solution with
a small quantity of surfactant to wet the job. That was a long
time ago approx 30 years so the details are not that fresh when
I was a lab technician at GKN Hilton and Tuck Electroplating
Division in the UK
Derek
Why do you need copper plating? The electrical conduction through a steel
rod is plenty for a ground, and a thin layer of copper on the surface isn;t
going to make a significant difference.
Is it for preventing rust? Galvanizing would probably be better. I say
just bend it. If you need heat, then you will damage the copper in those
areas, but the thing will still make a usable ground which should last for
years. You could paint the damaged parts with some zinc primer, or smear on
some roofing cement.
*********
Code in my area calls for each ground rod to be driven straight into the
ground (approx. 6.5 feet). If ones house system is not grounded onto a
municiple iron pipe water system, then two such ground rods are needed, 6
feet apart, connected by an unbroken #8 bare copper solid wire to each other
and the meter. If connected to a water system, then no ground rod(s) are
needed.
If the ground wire between the two rods, and the meter is not encased in PVC
conduit, then the metal conduits have to be grounded to the bare wire also.
** Posted from
On Wed, 30 Apr 2008 23:45:54 -0800 in rec.crafts.metalworking,
"SteveB" wrote,
Are they going to drive the rod into the ground with bends in it? I
don't see how that is going to work.
That is why you cold-bend them in place. A typical situation is where a
foundation extends beyond a wall (usually a few inches under ground), but you
want the ground rod to emerge from the dirt next to the wall. First you drive
the rod into the ground (usually a foot or two away from the wall) and then bend
it so that it wraps around the top of the foundation and pops up right next to
the wall. Any electrician with more than a few weeks on the job should be able
to do that in his sleep.
Vaughn
Copper in solution can be super saturated and dip deposited. That is normally
a thin layer at best. Plating is the best way - take a copper
pipe/sheet/wire.... and the sheet you want as the other electrode.
There are reasonable web sites that show electro-plating and offer chemicals
to aid and do the whole job.
Often large crow feet are used with the object suspended above the foot.
Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
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The copper clad can carry hundreds of amps when asked upon. The steel can't.
Electrons flow on the skin. A clamp on the outside puts or gets electrons
to or from the ground.
The ground is the important point that the electric company uses at your house.
When you have a power line hit and you have a protective circuit dump the
garbage signal (noise) onto the ground line, you don't want it to float.
Floating puts it on all of the other ground lines in the house.
You save the PC on phase 1, but kill the Plasma TV on Phase 2 - both sharing
the common line in the box and common ground connected to the common line.
Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
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Leo Lichtman wrote:
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Just a quick question here. If the extremely thin electroplated
coating on a steel ground rod will carry hundreds of amps, as you say,
hows come my 250 amp welder has them big thick cables coming out the
front, there?
Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)
I think Martin is generalizing incorrectly about the skin effect, which
applies only to high frequency AC. It's a phenomenon that becomes important
at radio frequencies. At DC, or at low frequencies, conduction is uniform,
or nearly so, across the whole section of a conductor.
Of course, copper has something like 10 times the conductivity of steel, so
you have to take the thickness of the copper cladding into account, too.
--
Ed Huntress
No, if the fire charred rod is unacceptable to the inspector, I will just
cold bend the next one. I was wanting to coat some other pieces of metal
with copper for decorative work, and wondered how to do it.
Steve
The ditch has been dug. They just wanted to make it conform to the concrete
foundation and follow the concrete outside that. It will be placed in there
and buried.
Steve
Most of the copper coated ground rods I see are electroplated and the
plating is maybe 0.0005 thick. I don't believe it carries much
current.
Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)
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