I would suggest, "Don't do it!" Whether the compound uses the acetic
acid, or a non acetic curing agent, these are water proof. They are not
moisture proof. I've seen them used for years with no problems and I've
seen them fail in less than a year. Silicone greases are a much better
choice. I worked for the company that developed these compounds and
greases for many years. (over 33 years by the time I retired)
If you can find it, DC-4, or DC-5 compounds (Silicone grease) is ideal
for flooding connectors. I'd stay away from anything that cures. There
is no need and it can make the connectors a Bit...ch to get apart. Most
any "non conductive" Silicone grease is great and should be available at
most automotive stores. Just don't try to get tape to stick on anything
with Silicones on the surface.Unlike hydrocarbon based greases, it's non
conductive even if it breaks down. (there is no carbon in it, When it
breaks down you normally get SiO2 (Quartz powder, or chunks)
I once saw some commercial circuits potted in plastic cases. It
completely dissolved/corroded the runs on the PC boards.
NOTE DC-4 and 5 compounds were developed for use in WWII to keep the
spark plugs in B17s and B24s from arcing over at altitude.
HOWEVER there are side effects to flooding connectors. It allows for
pressure changes between the inside and atmosphere with both temperature
and atmospheric pressure changes. This can cause the grease to flow, or
moisture to "wick", Even the aquarium seal is not moisture proof. It
uses the moisture in the air as a catalyst for curing. It can allow
moisture migration and condensation.
OTOH I've seen plain old UHF connectors, screwed on over the braid of
RG-8 folded back, out in the weather with no waterproofing, or even tape
and it had been out there for years! I've seen the same type of
connections covered with house paint. They had been in use for decades
(how many, I don't know, but the hams using them had no complaints. How
much of the power going into the coax was actually getting to the
antenna and being radiated as desired? Who knows? But again, like many
hams using big, expensive, poor performing antennas, they made contacts
as desired and were apparently satisfied.
As a new ham using a light bulb for a dummy load, I worked some DX.
Surprised? Certainly. Satisfied? Certainly not!
Ideal band conditions made up for a less than ideal dummy load.
Filling the connector and then sealing it with tape should really slow
the curing process. <:-))
73,
Roger (K8RI)
On 5/28/2015 3:25 PM, n8de@thepoint.net wrote:
Before screwing the outer shell on the inner portion, flood the inside
of the connector with RTV silicone seal (non-acetic acid type - like
aquarium seal).
THEN .. screw the outer shell tightly onto the inner portion .. and do
the 'double tape wrap' suggested by others.
No water going to get into the connector/coax to do damage.
73
Don
N8DE
Quoting Patrick Greenlee <patrick_g@windstream.net>:
A good wrap of electrical tape lasts pretty well and can be built up
pretty easy just in case you have tape but not the right size of
shrink.
Patrick NJ5G.
On 5/27/2015 10:08 AM, Doug Renwick wrote:
Roger try putting some thick walled heat shrink over the jaws like
3/4" and
shrink it down. Yes it needs to be replaced every so often but it sure
protects the connector shell.
Doug
I wasn't born in Saskatchewan, but I got here as soon as I could.
-----Original Message-----
Use a thin sheet of Silicone rubber in a "U" shape inside the
pliers to
protect the connectors. It works for me, but I'm often too
impatient to
worry about a cheap PL-259 (Even Silver plated Amphenols are cheap)
BNCs are basically miniature N connectors, bur they lose a lot to scale
and are very weak. I've never seen them used outdoors. It tales
little
strength to pull the coax out of one, making them an interconnect only
for me.
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Roger (K8RI)
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