[TowerTalk] Al-to-Al

[john at kk9a.com]

I found this interesting oxide inhibiting post by WA4VZQ:
http://www.qth.net/pipermail/antennas/2002-August/002328.html

John KK9A

Sent via the Samsung Galaxy 7 edge, an AT&T 4G LTE smartphone.

On Fri, Feb 16, 2018 at 2:46 PM, Wayne Kline <w3ea at hotmail.com> wrote:

> Some Say Tomatoes Some Say tomottoes  ...
> As with most on the list antennas  are in our Blood.
> my fist beam a Mosley TA33Jr. came with a  plastic tube of Gray Penetrox
> My Stint as an industrial electrician  We use  Dow Noalox  buy the gallons
> on ALL connection  Bugs , Lugs and switch gear.
> My first installation of the then Bencher Sky Hawks ( a three high stack )
> during assembly then came with this GOOP called Monkey stuff ??? if my
> memory still intact.    Over the years of installing and assembling
> antennas it became painfully obvious  when any of the  products were not
> used in assembly. !!!
>   I just last year  got my hands on an original design  Skyhawk and the
> elements  came apart  A -OK  but the GOOP !!!!  a red scrubby pad and lots
> of Lacquer thinner to clean the joint area.
>  I assembled it with the  Jet Lube SS-30 Amazon .com
>
>   Again my area is not In a Salt Spray environment   just ice,  snow, wind
> and rain  !!!
>
> YMMV
>
> Wayne W3EA
> ------------------------------
> *From:* TowerTalk <towertalk-bounces at contesting.com> on behalf of
> john at kk9a.com <john at kk9a.com>
> *Sent:* Friday, February 16, 2018 1:23 PM
> *To:* towertalk at contesting.com
> *Subject:* Re: [TowerTalk] Al-to-Al
>
> Penetrox has zinc particles and the SS-30 that K3LR uses has copper. Zinc
> is much closer on the galvanic chart to aluminum than copper which
> concerns me.
>
> John KK9A
>
> To:     towertalk at contesting.com
> Subject:Re: [TowerTalk] Al-to-Al
> From:   Patrick Greenlee <patrick_g at windstream.net>
> Date:   Fri, 16 Feb 2018 09:42:52 -0600
>
> Conductors (at least metals) are rated on an electromotive scale.  The
> farther apart they are on the scale the greater the voltage generated when
> an electrolyte is present. Stick a piece of aluminum into a lemon (citric
> acid solution for electrolyte) and also stick in a piece of copper and
> touch the two metals with your multimeter probes and note the voltage.
> Switch over to current measurement and see the short circuit current the
> little battery will produce.
>
> When dissimilar metals (different ratings on the electromotive scale)
> touch in the presence of an electrolyte (acid rain, salty ocean breeze,
> etc current flows and the less noble metal is eaten away by  electrolysis
> (AKA electrolytic corrosion.)
>
> Zinc particles in an oil or grease base are protected from contact with an
> electrolyte. When a joint has Penetrox or other equivalent zinc particle
> bearing paste in it and is tightened the zinc particles are in contact
> with the two substrate materials to be joined, promoting good conductance
> and are protected from galvanic action by the oil/grease.  By itself zinc
> is not magic and will corrode easily.  You wouldn't want to use zinc
> washers in place of the zinc particle loaded paste.
>
> Replaceable pieces of zinc are used on prop shafts and propellors to
> protect the shaft and prop from damage by electrolysis. The zinc is
> considered a "sacrificial element" as it is eaten away by electrolysis
> while protecting the prop and shaft. Many of the 6 gal water heaters found
> on RVs have replaceable sacrificial zinc rods in them. In that service
> corrosion of the replaceable zinc is intentional to protect other
> components.  In joining aluminum antenna components you don't want
> corrosion and the zinc in the paste is not intended to be sacrificed to
> protect the aluminum.
>
> Anyone want to design sacrificial zincs to put on antennas?
>
> Patrick        NJ5G
>
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