[TowerTalk] Copper wire prices

[K8RI on TowerTalk]

I doubt Alodine would be very effective for buried radials and it is a lot 
of work.

The Aluminum is etched with Phosphoric Acid, thoroughly washed and then 
given repeated treatments
http://www.rci-products.com/ALODINE.html
of Chromic Acid each of which is followed by thorough washing.  This 
produces the Gold color which is relatively fragile.  A good rubbing with a 
dry paper towel will remove it.  OTOH if handled carefully the majority of 
the wire would remain coated. In a cold climate like here in Michigan the 
freeze and thaw cycle would eventually remove the coating by the abrasive 
movement of the soil. How long that would take I have no idea.

A gallon of etch and Chromic Acid will run some where in the neighborhood of 
$20 as I recall.  However you can purchase the chemicals and mix your own 
for far less per gallon. OTOH  that's not cheap either. 
http://www.eaa1000.av.org/technicl/corrosion/alodine.htm  contains the step 
by step process.




> ORIGINAL MESSAGE:
>
> On Thu, 16 Nov 2006 12:55:10 -0600, "k6xyz" <k6xyz at sbcglobal.net>
> wrote:
>
>>Any problem with using aluminum wire for a radial system??
>
> ------------ REPLY FOLLOWS ------------
>
> I'd suggest you chromate it first using Alodine or the equivalent. I
> have no experience with chromated aluminum buried in the earth, but
> above ground it becomes highly corrosion resistant, even to
> concentrated salt spray. I'd think it would do very well underground
> too.

The difference between bare aluminum and Alodine coated Aluminum exposed to 
salt spray is 150 to 200 hours for the Alodine coating and a few hours for 
the bare.

Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com (Use return address from home page)
>
> Bill, W6WRT
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