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
On 2/15/2018 9:52 PM, Kim Elmore wrote:
From this thread, I learned that stainless steel and aluminum are a corrosive
combination. I hadn’t heard this before.
I’ve known that copper and aluminum are a corrosive combination and so the Jet
Lube SS-30 surprises me. But I also wonder about zinc (the main component of NoAlOx,
OxGard, and Penetrox) and aluminum. Is that truly a combination that plays well
together?
Kim N5OP
"People that make music together cannot be enemies, at least as long as the music
lasts." -- Paul Hindemith
On Feb 15, 2018, at 18:44, Kim Elmore <cw_de_n5op@sbcglobal.net> wrote:
I asked the question to make sure something was needed for Al-to-Al and it seems it is
truly is. Long ago, I was told that Al-to-Al was best dry because galvanic corrosion
couldn’t
When I was In CO, I used some stuff called OxGard because it was supplied with
an antenna. It seemed to work well there, but CO is very dry. OxGard has a
petroleum grease containing graphic and zinc particles. After about 10 y in CO,
everything seemed fine and when I took the antennas apart to move to OK, the
grease was still greasy. I used it when I reassembled the antennas here. But, I
always wondered if the stuff was truly necessary.
Kim N5OP
"People that make music together cannot be enemies, at least as long as the music
lasts." -- Paul Hindemith
On Feb 15, 2018, at 16:45, Keith Dutson <kdutson@sbcglobal.net> wrote:
May have something to do with weather conditions. I noticed Penetrox seems to
dry out quicker here.
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Bill M
Sent: Thursday, February 15, 2018 4:24 PM
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] Al-to-Al
We found when we took older antennas down where Penetrox was used were corroded
together or extremely hard to separate. We went to Noalux 30 years ago and
haven’t looked back.
Bill W2CQ
On Feb 15, 2018, at 9:05 AM, Keith Dutson <kdutson@sbcglobal.net> wrote:
Cannot find Noalox here in these stores in Houston. Penetrox is available, and
I keep a supply in the shack for general use. Seems to be pretty much
identical to Noalox for my use.
73, Keith NM5G
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
john@kk9a.com
Sent: Thursday, February 15, 2018 7:17 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Al-to-Al
Noalox seems to be more available at the big box stores, I wonder why Penetrox
became popular with amateur antenna builders.
John KK9A
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Al-to-Al
Date: Wed, 14 Feb 2018 16:09:29 -0500
We’ve tried pretty much everything in our salt air environment of South
Florida. Most here use Noalux successfully over the past 30+ years.
Bill W2CQ
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|