[TowerTalk] Water in Conduit... the fix

Jim Thomson jim.thom at telus.net
Sat Mar 7 12:31:28 EST 2015


Date: Fri, 06 Mar 2015 14:26:36 -0500
From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk at tm.net>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Water in Conduit...  the fix

### ...
If u use a weep hole,
> use the bare min.. like one...maybe two at most...and no bigger than  .15625 dia,
> ( five sixteenths).   .125 inch or less is usually not big enough..and can become plugged with debris.

######  oops.... I meant to say  5 / 32  of an inch  =  .15625 inch diam. 

Jim   VE7RF






If you must use weep holes, I'd keep them very small.  In many areas 
5/16ths is far too large! The reason is bugs, Wasps,  and spiders.  We 
seem to have gained a massive increase of paper wasps, Mud Dobbers, and 
those tiny nasty tempered Yellow Jackets over the past few years.  
Yellow jackets seem to prefer cooler locations as in the ground and 
under garage floors.   Mud Dobbers and Paper Wasps like enclosed spaces 
like the tuning unit for my Hy-Gain AV640 ( 
http://www.rogerhalstead.com/ham_files/AV-640/AV640.htm ) 6th photo 
down. Text gives explanation.  The little, stock drain hole was still 
large enough for them to get in.  RF killed a few, causing others to 
gang up on the threat, causing a massive mess.

Last summer I removed nearly a dozen Paper Wasp nests from our 200 X 
200' lot.  Some were larger than a football.
I opened the small 8' garage door on the West end of the South side of 
the shop to find a new nest of unhappy wasps. Only got stung twice 
before I got the door closed.

Several years ago, the whole neighborhood had more than that per 100' X 
200' yard.

73

Roger (K8RI)



On 3/6/2015 1:00 AM, Jim Thomson wrote:
> Date: Thu, 05 Mar 2015 08:22:58 -0600
> From: Patrick Greenlee <patrick_g at windstream.net>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Water in Conduit...
>
> Those of you unable to keep water out of your conduit have my sympathy.
> I know how irritating it could be. If your conduit is assembled properly
> and doesn't leak leaving the airborne moisture as your target then put
> desiccant bags in the conduit and plug the ends of the conduit where the
> cables enter/exit.  Various ways to plug include duct tape, spray foam,
> wadded up paper coated with silicon caulk or...
>
> Patrick   NJ5G
>
> ####  .....or  use  DUCT SEAL.  Available at any home depot...in the electrical dept.
> Comes in 1lb packages.    It?s the Standard to use to seal conduit ends. At the telco
> I worked at, they had it in 10 lb bags.   Duct seal works  great..since its like kids plastercine.
> Pliable, and easily stuffed in there, and molded to fill all the air gaps.    Easily removed when
> it comes time to add one more cable... or remove a cable.
>
> ##  leaving conduit open is just asking for trbl.   Even if the conduit terminates  inside your
> basement, or terminates inside a metal or plastic nema  box,  you still use duct seal.
>
> ##  In nema boxes out doors, or stuff like remote ant switch boxes, etc,  put a lot of
> desicant inside..aka.. silica gel.   Silica gel absorbs up to 40% of its weight in water.
> Seal the boxes up air tight..then with silica gel inside, they will be bone dry.  Change
> the silica gel out once every year.   If a box has power to it, a pair of those metal
> finned resistors and some voltage through em 24-7 also works very well.   Just a bit
> of constant heat will ensure the box remains  dry..and the silica gel absorbs the rest.
> 2nd resistor is for redundancy.
>
> ##  Im not a fan of metal nema boxes, since they are more prone to condensation forming
> on the inside.  Some will use weep holes on the low point to let water out.  If u use a weep hole,
> use the bare min.. like one...maybe two at most...and no bigger than  .15625 dia,
> ( five sixteenths).   .125 inch or less is usually not big enough..and can become plugged with debris.
>
> ##  If the weep hole is made too big, the silica gel inside will begin to try and absorb moisture
> from the outside, high humidity ari..like rain and fog, high humidity condx, etc.
>
> ##  Install large diam conduit ..like the 4 inch stuff....and forget putting holes on the bottom side of it,
> Utilities don?t.   Make sure its all bone dry b4 gluing the sections together.
>
> Jim  VE7RF
> _______________________________________________
>
>
>


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