[TowerTalk] Amount of "Goop" to use in Telescoping Aluminum Tubing Connections?

[Gene Smar]

Rich:

     When I built my HF Yagi (Bencher Skyhawk) in 2001, I followed the then-recommended practice from TowerTalk to use a minimal amount of No-Al-Ox on the elements joints.  I cleaned the inside of the larger tubing and outside of the smaller tubing with a Scotchbrite (R) scouring pad.  I used this plastic pad so as not to leave any traces of iron from steel wool pads on the aluminum surfaces that could cause galvanic corrosion from the dissimilar metals.

     I applied a small amount of No-Al-Ox with the included brush to the mating surfaces and wiped it off thoroughly with a second, CLEAN Scotchbrite pad.  I used this second pad so as not to deposit into the No-Al-Ox the dirty material I had just removed from the aluminum with the first pad.  I telescoped the pieces of element tubing together and applied the requisite rivets to the joint.

     I have not attempted to disassemble the Yagi yet so I can't attest to whether the No-Al-Ox was applied in sufficient or deficient quantity.  But so far I don't have to care.  The antenna still works for me.

     YMMV.


73 de
Gene Smar  AD3F


-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Richard Smith
Sent: Tuesday, May 22, 2018 8:04 PM
To: towertalk at contesting.com
Subject: [TowerTalk] Amount of "Goop" to use in Telescoping Aluminum Tubing Connections?

"Goop" = Penetrox, Noalox, Jet-Lube SS-30, or other

A while back, there was a good discussion on this reflector of which goop is recommended for telescoping aluminum tubing connections in antennas. My question here is not intended to recap all of the "Which Goop is Better" points, but rather to ask how much goop to use. Over the years, I have heard recommendations from "very minimal" to "lots". 

I would be interested in recommendations from this very experienced group. The trade-offs in my mind are:
Very minimal amount: Pros: Allows the aluminum to aluminum contact to provide the electrical connection. The goop provides some lubrication, maybe some corrosion protection.                                   Cons: Not enough corrosion protection, not much help in separating telescoping parts when desired years later.
Lots of Goop:           Pros:  Assists in making a good electrical connection, provides more corrosion protection, easier to separate parts when desired years later
                                Cons:  Maybe too much lubrication, harder to get hose clamps tight enough to prevent unwanted slippage.
Maybe this is very basic, but I am interested in your comments.

Thanks in advance,
73, Rich, N6KT



   
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