[TowerTalk] Aluminum clad wire

[WA2PUQ]

All:

There has been quite a bit of conversation regarding the use of wire nuts on
aluminum wire.  While it will probably not be a problem with ham antenna
uses, I have seen wire nuts with burned insulation because the aluminum
wire, even while twisted together, had the mentioned steel spring in the nut
being used as the only connection between those wires.  The spring makes a
fine toaster element and the nuts looked it.

The reason is that the aluminum oxidizes almost immediately after the
insulation is removed even if the wire is scrubbed to clean it (that's why
it lasts so long without rusting).  The trick here is to use a piece of
green ScotchBrite impregnated with Alconox.  The scrubber strips the oxide,
the Alconox keeps it from returning so the wires actually make a usable
connection when twisted and nutted.  And no, the flooded wirenuts are not
the answer if the wire is not treated as described above.

For aluminum house wire remediation a new crimp tool and sleeve has been
introduced by the Burndy corp. which is available only to certified
electricians on a rental basis at several dollars per connection.  There is
also a three cavity flooded set screw locked wiring device (Alumicon comes
to mind) at 5 bucks per connection, but you don't need the expensive
crimper.

I had to learn about this as my brother in law has an AL wired house and we
had to make a few repairs there.


----- Original Message ----- 
From: "Hans Hammarquist" <hanslg at aol.com>
To: <towertalk at contesting.com>
Sent: Thursday, December 30, 2010 3:29 PM
Subject: [TowerTalk] Fwd: Using aluminum wire [or aluminum clad wire]


>
> It is the square, hard pin that is the secret behind the good and reliable
> connection of wire wrapped connections. You will not even get a close
> result if you wrap a wire around a round pin. (Been there, done that, and
> that was tin plated Cu wire on tin plated Cu pins.) You have the same
> mechanism with wire nuts. Inside the nut is a spiral spring made of square
> wire. The sharp corners will press themselves into the softer metal in the
> conductor and form a "gas tight" connection.
>
> I wonder if we can use wire nuts to make the connections to Al wires in
> antennas. Simple and cheap. Any comments?