Silicone Goo

[Detroit47]

I am putting new coax on my 6 meter beam. I wasn't sure if plain old silicone would be OK to seal the end of coax. I have the usual pig tail arrangement. The shield goes to the boom and the center to the gamma. The coax I took down was tarnished black from rain, air.... I have some plain old permatex blue rtv is this ok to use?

73 N8QPC

[w3jn]

Probably won't handle the UV light very well.  Best stuff is that gummy coax sealer.  Used to be available at Radio Shack.

[WQ9E]

Follow JN's advice.   A lot of the silicone sealant out-gasses corrosive byproducts during the cure process which won't do your coax/connector any good.

For one time use, I have used electrical tape a lot and never had a problem with water intrusion.  But that won't work if you are not careful with the wrap.

[Mike/W8BAC]

I recommend Butyl Tape John. The coax seal stuff they sell is the same butyl product but in a small package and expensive. Butyl tape is used to stick and seal windshields in place. It's uv resistant and won't harden or shrink. You can pick up a roll at NAPA and it will last a long, long time.

I prep the joint with a careful coat of 3M "33" black tape and cover that with butyl. The black tape can be slit later and pealed off with the butyl if needed. If you go butyl only you will never get it off.

I have a roll here if you need some. Like I said, it lasts a long time.

[WBear2GCR]

Standard silicone rubber cures by releasing acetic acid when moisture is present.

They do make a non-acetic acid version. GE used to have it as "Sil-Pruf". A search might
reveal this. Of course you have to do some looking to find a distributor that handles professional
products, not consumer stuff...

I'd go with what we used to call "monkey goop"... that sealing tape stuff that is kinda gummy and
stretchy, and is used by the power company and the phone co for sealing stuff...

                 _-_-bear

[W3SLK]

My 5¢ worth. I use regular black electrical tape, then cover it with self-vulcanizing splice tape and another layer of electrical tape. I've had connectors up for 10 years that looked like the day I placed them there. YMMV

[KL7OF]

I have some coax connections made with the red hi temp gasket silicone goo......because thats what I had to use at the time....For what its worth, it has held up leak free and still in use on a Qro coax exposed to the weather for at least 8 years......  I like black e tape too....   

[n2bc]

Coax Seal is good, but nasty to remove & pricey.  Get some Dust Seal at any good electrical supply, comes in 1 and 5 pound bricks - used around the service entrance at the top of the electric meter, lasts forever.

I cover the stuff with Scotch 88 electrical tape, good to vy low temps & not UV sensitive.

I've opened up connectors after 10 years outside & they look like new.

UPDATE Aug 30:  (Bad eyes and fat fingers)   Not 'dust' seal but DUCT seal.   The lump I have is NEER Manufacturing Duct Seal Compound, UL approved.  "Has greater adhesion properties for sealing around service entries, junction boxes, flashings and service mast conduit.  Use indoor or outdoor where a permanently soft non-staining sealer is required to seal out weather, moisture, dust and atmospheric conditions"

[flintstone mop]

Coax Seal is good, but nasty to remove & pricey.  Get some Dust Seal at any good electrical supply, comes in 1 and 5 pound bricks - used around the service entrance at the top of the electric meter, lasts forever.

I cover the stuff with Scotch 88 electrical tape, good to vy low temps & not UV sensitive.

I've opened up connectors after 10 years outside & they look like new.

Good advice, price is not important. Wet connectors and coax at VHF and UHF gets nasty. Type N is waterproof.
But the suggestion above will be a 10 yr connection minimum.
Fred

[W9GT]

I have used the self vulcanizing gray sealing tape and it works well.  I usually cover it with regular black vinyl tape.  DX Engineering (I have no connection with them) recommends the black Permetex RTV stuff.  It, in contrast to the clear or blue (or other colors?) variety, it is non-corrosive.  DX sells it or you can just pick up a tube at your local car parts place.  In the past, I used the clear stuff and after some period of time...opening up a connection... found discoloration and some corrosion of the connectors.  You can, however, use black tape over the connection...then seal the outside with RTV of any sort and that seems to work OK.  The problem, however, that I have observed is that sometimes you get some moisture accumulation from condensation inside.

Another good way to go is use heat shrink tubing over the connection...then cover with black vinyl tape...works great and seems to last.

73, Jack, W9GT

[W1VD]

I've had good luck with adhesive lined heat shrink tubing. The tubing is thicker than garden variety heat shrink and comes in various shrink ratios. UV resistant - some connections here are over 10 years old and show no signs of deterioration. To take apart cut and peel away the black tubing and remove the remaining clear 'goo' with mineral spirits. 

http://www.mcmaster.com/#adhesive-lined-heat-shrink-tubing/=8mmvrl

[WU2D]

I have been using Butyl windshield tape as mentioned above. Go to auto parts store and buy a lifetime quantity.

[Detroit47]

Thanks for all the input guys I bought some of the windshield tape worked great.

John