[TowerTalk] non conductive sealant

[Tower (K8RI)]

FireBrick wrote:

> Can anyone suggest of brand of sealant that can be used on antennas 
> that's non conductive?
> I'm thinking about silicone type sealants.
>
> I had tested a glob of silicone I had using the unscientific VOM and 
> found that it was conductive.
>
Silastic RTVs from Dow Corning and those from GE both work fine (Bat tub 
caulk, weather sealant).  Just do not put them in an area where then can 
not cure and outgas.  If it has a sharp oder like acetic acid it's 
because both use acetic acid and cure using water vapor.  Used in the 
open whey work well. Used in a tight enclosed space they are a tad 
corrosive.

Dow Corning also makes a non corrosive version (really smells) If you 
can find it.  They also make one that is conductive (black) which is 
really hard to find.

On antennas and baluns they work fine.  Let cure at least a day although 
you'd probably not notice a problem using it sooner.

OTOH don't use them to pot printed circuit boards.
The company I worked for purchased a rather large batch of circuits that 
were supposed to work in a hostile environment.  They worked great for 
about 6 weeks.  They all quite within just a few days of each other.  
The stuff ate the foil right off the circuit boards which were potted in 
plastic enclousures.

<snip>

>
Roger Halstead (K8RI ARRL Life Member)
Worlds Oldest Debonair (N833R S# CD-2)
www.rogerhalstead.com