The stainless steel bolts on my antennas in Aruba show a little corrosion
(very little) on the head. I'm note sure of the grade, they were purchased
at Ace Hardware. I also get some salt buildup and probably sealing the
joints as you did is a good idea. I built my monobanders using the 120MPH
taper schedule in the ARRL Antenna book and hopefully the tips will stay in
place for a while. Aruba has a lot of wind and the tower and antennas are
constantly moving. I believe this fatigues the aluminum and it is likely
the reason many in the area have problems with broken element tips. Trying
to preserve the steel tower seems to be my biggest maintenance challenge.
John KK9A / P40A
From: "Georgens, Tom" <tom.georgens@engenio.com>
Date: Sun, 13 Feb 2005 17:50:08 -0800
List-post: <mailto:towertalk@contesting.com>
Salt corrosion is a subject close to my heart. In fact, in about 48 hours,
I will get to see the latest bit of wrath nature has wrought on my station
in Barbados.
Any steel that is not galvanized or stainless will rust in a few months.
Copper split bolts will turn green overnight. That said, I have never seen
stainless corrode like some others have reported.
One lesson I learned is that all element joints have to be protected. While
dissimilar metals are part of the problem, my biggest problem has been salt
building up on anything that protrudes into the airflow. It was very common
for salt to build up around clamps and antenna joints. This weakens the
aluminum and makes it prone to vibration damage. When I first took over the
station, 4 element tips has broken off and there were a bunch more broken
tips in the storeroom. On top of that, it makes it nearly impossible to
disassemble the elements.
My solution has been to tape across all element joints using a good tape. I
then overcoat it with liquid electrical tape. I was very skeptical of this
stuff but it has worked very well standing up to the water, salt, and UV. I
have yet (and I emphasize yet) to lose an element tip, and it has the added
benefit of making it easier to take the elements apart.
In the last few years, I have learned many lessons the hard way but things
are getting better.
On the other hand, keeping the computers and incoming phone service working
has been a perpetual problem.
73, Tom W2SC 8P5A
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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