Art,
You have brought up a point that I have wondered about for sometime, and it
is hose clamps. I have put up lots of yagis (including Cushcraft, KLM, Force
12, Hygain etc. Most use stainless steel hose clamps like you are
discussing. Until a few years ago I always used these SS clamps without a
second thought.
I had two experiences that made me reconsider what I was doing. The first
was putting up a KLM 15 6 element yagi. It had been up for a few weeks when
two of the hose clamps popped and broke. I have always thought that I had
tightened them too tight and the extremes of the temperature here in South
Texas had done the rest. The elements slowly slid out and fell to the
ground. I began to worry about how tight I should be tightening those
clamps. With a ratchet, it is easy to break or over-tighten hose clamps.
(Incidentally, I would replace those hose clamps while the antenna is down.)
My second experience was the construction of the Force12 C3 antenna. I was
amazed that the elements were riveted together and did not use the standard
hose clamp. After 3-4 years I had to take the C3 down because we moved. I
saw none of the "wallowing" damage that had been discussed elsewhere, even
though we have fairly consistent winds. (Of course, no ice here!) Even
though I had no problem with this I was worried because some pretty smart
folks had mentioned it.
I decided when I put up the tower I have now that I was going to use the
stainless steel clamps AND rivet on each overlapping section. This will
protect me from having an over-tightened hose clamp and the clamp will
protect the rivet from the "wallowing effect" that has been discussed
elsewhere. Riveting is very inexpensive, easy to do, and easy to remove it
necessary.
I thought you might want to consider this. I was wondering is anyone else
has had any thoughts on the idea of rivets/clamps?
Bill, W5VX
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Artmouton
Sent: Monday, March 03, 2008 7:11 AM
To: towertalk@contesting.com
Subject: [TowerTalk] hose clamps and end caps
Having received such good assistance and info from this group, I am
completing the cleaning of the Cushcraft A3 (w/ 40 meter addition) and am
requesting further guidance from the group. The antenna is in great shape so
is just being cleaned and Ideal Noalox being put on the joints.
I noticed that the prior owner had used a few non-stainless steel hose
clamps - not good - one even had started to corrode the elements. I will be
changing the non stainless ones and a few others that show problems
So the questions are:
1. Do I just change all of the hose clamps? Most of the good ones have
stayed in great shape, screwed off easily and no real deterioration. Is it
just good practice to change all of them, regardless of condition. Found
the stainless ones at Lowes - 2 for $1,40 or so.
2. I noticed that the prior owner had "sealed" some of the hose clamps by
putting some type of substance on the screw area to probably lock it in
(more than protect it). It was not on all of them and did not seem to make
any difference in tightness of the clamps. Is it necessary to seal the
screw areas to keep them tight? If so, is there any suggested substance to
use to accomplish this?
3. The end caps on the traps were all in good shape. Some stiffness but
they came off and went back on without trouble. Is it just good practice to
change all of them just to be sure?
I did take apart a few of the traps based on the recommendation and guidance
from the list. No real problems. The coils on the traps are wound tightly
around the center part of the trap and sealed. The coils were all in
perfect shape of those I opened. Looks like they are very well made.
Hope to get it up on the tower soon.
Got DX to work....
73, Art K5FNQ
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