Adding to Vic's previous comments... from my own experiences...
At 10:54 AM 2/15/05, Vic Rosenthal wrote:
I've tried different methods of waterproofing outdoor coax connectors for
years, and here is my experience, for what it's worth:
3) Coax Seal -- Does a good job and is easy to use. I have had
connections sealed for years which have stayed dry. A little hard to
clean up when you take the connection apart.
I've found that Coax-Seal works best (for me), if I use it OVER an initial
wrap of good quality plastic tape (Scotch #33 or #88), and then OVER-WRAP
it with another wrap of good quality plastic tape. UV will kill coax-seal
if it's not protected from UV, and coax-seal is simply MISERABLE to remove
from just about ANY coax connector if you install it directly onto the
connector (without an inner wrapping).
For the past 5 years, I've switched to self-vulcanizing (silicone) tape...
see below.
6) Self-vulcanizing rubber tape -- I've never been able to apply it
properly, but looks like it would work well (although I don't know how it
would respond to UV). Tends to want to stick to itself, etc. Everything
is harder when you are on a roof or tower.
The self-vulcanizing tape I use was purchased at Dayton over 3-4 years,
from an amateur radio club in Minnesota... it is a gray silicone tape and
VERY flexible and stretchy (almost a 2:1 stretch factor). I apply this tape
directly to the coax connection, overlapping it about 50%. I then follow
with a final overwrap of 3M #33 or #88 tape. It has, so far, kept every(!)
drop of moisture from the connectors it's protected. There was no name on
the rolls of tape, but I'm told that they were donated to the radio club by
a 'very large' tape manufacturing company which has three similar letters
in its name, and this is also located in MN. Hmmm... apparently the tape
failed one or more of their QC tests, but was still good enough for most
uses, just not those for which the company was willing to have its name
shown on the product.
Self-vulcanizing rubber tapes I've seen should work just as well. If they
appear to want to really stick TO the coax connector (such as Coax-seal
does), you might want to first apply a protective "don't stick to me" wrap
of plastic tape (even the cheap stuff will work here), and then apply the
self-vulcanizing rubber tape, and finally a UV protective layer of good
quality plastic tape.
Finally, the question of how to 'terminate' a taped wrap... some just pull
it tight and then yank on the tape until it breaks, wrapping the loose end
around the already-taped connection.
I've found, from experience, AND from numerous suggestions from those who
have done a LOT more if that I, that when terminating a wrapped connection,
it is best to pullout a loose end of maybe 3"-4", CUT it off, and allow it
to hang free for a short period of time, to allow any previous stretch to
be recovered by the loose end. Once it has returned to its UNstretched
length, wrap it snuggly around the taped joint, using the larger diameter
of the taped joint if possible and WITHOUT much pulling on tape as you wrap
it. This allows the tape to seal against itself well, but having not been
stretched, it won't want to unstretch later on when the sun comes out and
heats up the taped joint, softening the adhesive.
73,
Tom N0SS
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