Marlon,
Now thats a good explanation of how to do waterproofing correctly, that you
made.
The secret to good waterproofing is the right amount of stretch of the
Mastic tape. Its the stretch that allows the tape to optimally bond to its
surface and fill the gaps. Just pushing the goop in place does not allow it
to bond optimally. Remember temperature causes things to expand and
contract. Mastic tape is NOT glue. It sticks to itself very well, but not
necessarilly flush against other surfaces.
Anyway, there are many ways to skin a cat, as this thread has shown. . And
the third party Kit products were made for a reason, to simplify the
process. I'm sure most of them work as those of you have given testimonials.
But using good old Mastic, and Super 88 (or 33) is a cost effective way to
do it, well. For those that want to create the internal non-stick layer so
be it, but don't give up the tension applying the Mastic tape, as that is
what is making the seal. And make sure it extends past the inner layer as
much as possible, so it can bond to the ingress area. (Note: I stated
Tension on the Mastic, not the Super 88). Personally, I see little reason
to remove a connector from an antenna once its been installed. So I don't
worry much about taking the goop off. I deal with it, the few times its
required.
Tom DeReggi
RapidDSL & Wireless, Inc
IntAirNet- Fixed Wireless Broadband
----- Original Message -----
From: "Marlon K. Schafer (509) 982-2181" <[EMAIL PROTECTED]>
To: "WISPA General List" <[email protected]>
Sent: Friday, March 16, 2007 12:12 PM
Subject: Re: [WISPA] Moisture Ingress
sigh
Larsen, when can you and I hook up and do a video of the RIGHT way to
weather seal? hehehehe
First, John, I'm gonna assume that your guys know nothing so please take
no offence.....
The FIRST and MOST important step in a good water seal is the antenna!
Jer would be quick to remind me of that painful lesson as it applies to
the old Mobile Mark black 9dB omni antennas. The antenna connector at the
bottom was SCREWED into the mast below the weep hole. Water would
eventually wick down into the connection via the threads, no matter how
good you were at weather sealing. I LOVE those antennas, they work
incredibly well, but they just don't last.
You have to watch for things like people using those danged bulkhead
connectors with the flat sides on them. Also watch for the nut on the
outside of the connection. If it's not also covered there's a spot for
water to wick down into the connection.
When I run into those flat sided connectors I will stretch my mastic very
thin to make sure that I get the goop down into the cut down area. The
down side to this is that the mastic will eventually ooze into the threads
and make the connection REALLY hard to take apart. I always figured that
a connection that's easy to take apart will also be more likely to leak
though.
I try to get antennas that have a longer connector on them when I can. I
also require that antennas I use have room for a whole roll of tape
between the connectors and any other parts. If I can't put the tape on
correctly it will leak someday.
I tried using silicone on the connectors but that eventually shrinks and
there's something in it that corrodes the connectors. Bad idea.
I tried putting a layer of black tape on before I put on the mastic, then
I decided that that was a silly idea because that inside layer is the
water proofing and if it's easy to take off it's more likely to leak.
On the new Maxrad hpol adjustable beam sectors that I like so much I take
them to a machine shop and cut off part of the braketry so that I can seal
things up better. I'm not afraid to modify the mounting systems on
antennas if it'll let me do a better job of sealing them up.
I only use high end connectors. Times Microwave all the way.
Here's how I seal a connector:
Use one wrap of scotch 2228 mastic. Stretch it to half it's original
width and overlap each layer by half. This give you a two layer thick
coating. Start at the bottom about a half inch PAST the heat shrink. Heat
shrink is NOT water tight. It's a strain relief... Up near the connector
bulkhead end I will wrap the tape enough to make sure that there's a bit
blob of it around anything that might allow water in, especially the
bulkhead it's self. Then wrap back down to the middle of the connector.
Next I use Scotch 33+ tape (none of the cheap crap gets used anywhere
here). This gets two layers that are overlapped by half. Start so that
your LAST layer goes up. It should leave a pattern kinda like siding.
You want the water to run off of the seams not follow down into them.
This needs to be wrapped so that it's smooth, no creases allowed. A
crease is an air gap, air = water. Stretch the tape just enough to pull
to all of the wrinkles, too tight and over time it'll actually slide off
of the connector. It may do this over time anyway but once it's squished
the mastic into all of the nooks and crannies it doesn't seem to matter
much. Not making your tape too tight on the diameter transitions seems to
help with the problem though.
I just don't have water problems anymore.
Things that I've seen/done that fail. Almost always.
Heat shrink. The glue hardens when temps drop and you loose the water
tight seal. Yes I know it works in water wells, but the temps there are
steady.
Duct tape. Degrades in sunlight and many glues are water soluble.
Black tape alone, see above.
Silicone, shrinks and corrodes connectors.
Nothing. I know that there's a gasket in there, I know that the factory
says you don't have to seal them. They will leak.
Reusing antennas or connectors that got water in them. If you look
closely you'll see that the center pins have a discoloring. That's
corrosion and you'll never get a good connection out of them again. In
fact I usually chance the coax too.
Hope this helps!
marlon
Marlon
(509) 982-2181
(408) 907-6910 (Vonage) Consulting services
42846865 (icq) WISP Operator since
1999!
[EMAIL PROTECTED]
www.odessaoffice.com/wireless
www.odessaoffice.com/marlon/cam
----- Original Message -----
From: "John Scrivner" <[EMAIL PROTECTED]>
To: "WISPA General List" <[email protected]>
Sent: Friday, March 16, 2007 7:29 AM
Subject: [WISPA] Moisture Ingress
I would like a bit of feedback from those of you who have been installing
outdoor antennas for a while. I have a problem that I would like to see
fixed. It seems that after every long rain we see problems with the
occasional connection outside at the antenna getting water into it. We use
the Scotch seal mastic tape to seal the connections. The guys do not like
having to climb and they work hard to try to make sure we do not get these
problems and yet they come back. I would like to hear what you veterans
out there are doing to make sure the water stays out.
Thanks,
Scriv
--
WISPA Wireless List: [email protected]
Subscribe/Unsubscribe:
http://lists.wispa.org/mailman/listinfo/wireless
Archives: http://lists.wispa.org/pipermail/wireless/
--
WISPA Wireless List: [email protected]
Subscribe/Unsubscribe:
http://lists.wispa.org/mailman/listinfo/wireless
Archives: http://lists.wispa.org/pipermail/wireless/
--
WISPA Wireless List: [email protected]
Subscribe/Unsubscribe:
http://lists.wispa.org/mailman/listinfo/wireless
Archives: http://lists.wispa.org/pipermail/wireless/
