Sealing coax connections against weather

[poppafred]

I have ordered some of the sticky back tape for sealing coax connections against the weather but have been wondering:

Has anyone ever tried using Penetrox on the center pin and on the outer threads to stop corrosion?

I bought an 8oz bottle of the stuff to use on a new vertical and had tons left over. If I were careful to not get it across the insulator surface and kept it on only the metal surfaces, do you think it might help maintain good contact at the connector?

I've always just slapped everything together and gone on because I figured I could always go back and repair it but I am getting to the point in life that it isn't always going to be possible to correct mistakes. Figured I would do it right the first time and not have to fix it later.

 

[mmckenna]

I've never tried the penetrox inside the connector.
I have used dielectric grease inside other types of electrical connectors, you can usually buy it by the tube in a good auto parts store (not the chain stores, usually). I got a tube from Waytek Wire a few years back. I've never used it on RF connectors, not sure if it would be a bad thing or not.

Getting water inside the connector is only part of the issue. Getting down inside the coax is the other one. You can get water between the jacket and the outer conductor that will cause issues. Some of the cable designs can allow the moisture to travel down the cable. Some coaxial cable dielectric will absorb water on their own, or if an air core cable, allow it to run down the inside.

The best solution I've found is what most commercial sites use, All connectors are type N or 7/16 DIN that have proper sealing built into the design. All connectors have adhesive lined heat shrink used over the coax and the connector body. Once the connectors are mated, a pass of electrical tape is added, either adhesive down or adhesive up. A layer of mastic tape is layered over everything and molded over the connectors. Another layer of electrical tape. Then follow up with a coat of liquid electrical tape type liquid.

 

[K9WG]

I have used Coax Seal with very good results. Had a connector exposed outside for three + years. When I removed the Coax Seal it looked like new. No moisture penetration at all.

Coax-Seal protects connectors from moisture and corrosion

 

[kb0nly]

Here is my preferred method, works perfect every time, no mess, and doesn't leave any residue when you remove it.

Get yourself a roll of lined splicing tape, otherwise known as self amalgamating tape. It has a peel off liner on one side. For a connector on say an antenna, start a couple inches back on the coax and wrap it like you would with tape, except stretch it to half its normal width and overlap by half of that width. When you get to the connector its on go all the way to the base of the connector beyond the threads, if you want to add a second layer going the opposite direction, i have done it with one layer, but two is better. Then add a couple layers of Super 33+ electrical tape, the splicing tape is not UV resistant, so if its going to be exposed to the sun add the electrical tape for protection.

I have had connectors taped up in this manner for years, no water ingress. When you need to remove it carefully slit it down one side with a knife and peel it back and off, it will be a nice formed rubber boot, you can even see the negative of the coax connector and connection inside its a perfect rubber mold.

Coax seal leaves a gooey mess and discolors the connectors, every one i have removed over the years was a mess. With this method it comes off and looks like it was just put on. I took apart some connections that were 8 years old and they were absolutely new, not tarnished or discolored in any way, shiny and bright!

All the commercial sites i have been on do basically the same now, and the cable TV guys even direct bury connections that have been wrapped in this manner. This lined splicing tape is available at most of the big box stores, Gardner brand at Menards and Lowes, and some have the 3M version of it as well.

 

[rwilliek]

Try Rescue Tape....its a self sealing silicone tape that fuses to itself....its also stretchy. I get it from Bass Pro, but it is available plenty of other places as well.

Amazon.com: RESCUE TAPE Self-Fusing Silicone Tape ~ BLACK: Sports & Outdoors

 

[Rt169Radio]

I use black electrical tape,it works for me because my antennas are currently not high enough to bear the full brunt of the weather or nature.

 

[commscanaus]

I use Scotch Linerless Rubber Splicing Tape 130C by 3M.

Easy to apply and connections look like new when the tape is removed.
Like co-ax seal, you apply the tape in an overlapping fashion and mould it into itself.
It stretches well before breaking and can be applied tightly, conforming into gaps and connector threads. It survives well in the baking heat of our summers and would be fine in the freezing conditions of an icy winter.

Well worth getting some in my opinion, especially for use where antennas may be hard to get to for maintenance purposes such as tower mounted or mountain top as it will last quite a long time.

Commscanaus.

 

[poppafred]

Okay, FB on the tape.

So, what about the Penetrox A?

I have searched all of RadioReference for any talk about using it and I cannot find it even mentioned in a single post except my own.

 

[kb0nly]

I wouldn't bother... If you keep out the water then you don't have corrosion! Seal it up with the tape that me and others are mentioning and your good. That Rescue Tape is good stuff, i have used that on projects too, its just another brand of self amalgamating tape. I don't know about its longevity though, i have connections wrapped in Gardner and 3M splicing tape that are going on 9 years old.

Penetrox and similar products are intended to repel water, if you get water into the connection you already failed on sealing.

 

[mpddigital]

"I use Scotch Linerless Rubber Splicing Tape 130C by 3M."

Ditto, we started stocking it years ago as it is the best stuff ever. We also have found that the 3M mastic squares work very well and stock them but they are not on the web site.

We heat shrink all out connections on all cables made but that is NOT enough to prevent water infiltration that will significantly degrade your signal. PL-259 connectors are the worse as there is no way to make them water tight without extra sealing.

BTW, it is not the connector sealing that is the real issue long term but the infiltration of water into the cable jacket. Once you get it into the shield and dielectric you really can have issues.

Keep away from the cheap sticky Goop. 3M makes the best stuff we have found.

 

[poppafred]

Well, I contacted DX Engineering and they said the same as most of you:

Hello Fred:

Penetrox is made for aluminum-aluminum and aluminum-copper joints and contacts and contains zinc. If improperly applied, it could migrate through the connector and cause a short. Your better choice for protection within the connection would be dielectric grease.

73,

Mark Haverstock, K8MSH
DX Engineering
Akron, OH 44309

The coax I have ordered is the Davis RF Bury-Flex 9914 so moisture migration should not become a problem for several year. The Coax Seal 104 I ordered is used by the US military so it probably does a pretty good job.

Next is the hard part: trenching through the grass roots to get it in the ground. A friend said I could use my driveway edger and slice right through so it may not be that big a deal. I'll find out this weekend after the coax arrives and I get the connectors put on.

Thanks everyone, I appreciate you taking the time to respond and offer your insights.

73!

 

[kb0nly]

Just cause the military uses it don't mean nothing these days, they buy from cheap contractors that make them products to! I will make one last comment on Coax Seal, you will be sorry you ever put that crap on your connector... Moving On...

Getting the cable in the ground isn't hard. I have put in direct bury cable a few times with just a flat wide spade, push it in the ground and pry to one side, slip the cable in and move to the next slice, you will be surprised how fast you can work across the yard doing it this way. The edger method works too but it gouges out material, it basically digs a small trench, but it scatters the dirt all over the place and you can't easily refill the trench it creates. The spade and separate method works better, you just walk over it a few times to close the gap you created and in a week or less depending on soil and growing conditions you don't even know its there.

Another method i have used is a narrow sod cutter, they are harder to find though, a regular width one is readily available at most home centers and hardware stores, some places even rent them. Then all you do is cut the sod and roll it up, install the cable or cables by digging a small trench in the dirt then raking the dirt back flat over them and roll the sod back down, keep it well watered for a while and it will grow back in no time.

How long of a run of cable do you have? If its a fairly short distance, 50ft or less, i would just spade it in, quick, easy, and grows back fast.