Weather-proofing Coax Connections

mrlewp87

DTVUSA Jr. Member
#1
I'm gonna tell on my brother now. We live in different states, and nearly a year back I was serving up all sorts of advice (having just learned myself) on installing an OTA antenna. Trying to cover all the bases, including grounding and importance of good, clean connections, and preventing corrosion. He went a different way than anything I would've mentioned.
When it came to all coax connections with the protective boots- the balun, preamp IN/Outs- he stressed that he packed them (the boots) with "grease". I questioned him on this stuff he used, but only yesterday did I learn what it actually was. He sent a link to this funny named product;

Oatey Flanges Plumber's Grease.
Description; "A special combination of lithium soaps, solvent refined base stocks and additives"

My concern is this "grease" seeping into the connections. Even if a shorting of the conductors isn't a real issue, what about loosening of the threaded connectors? In particular, those on the short stretch of coax needed to allow full rotation of the antenna by the rotor. If you're using quality cable, it's not the limp kind that is easily twisted. I think there's bound to be some twisting effect on that short coax, which extends to the threaded connectors. So, if they're "packed" in grease, during a hot summer, I'm imagining the possibility of something bad happening there. Not to mention the solvents noted in the product description. When I'm up to see him soon, shall I suggest other options?
 
#2
I wouldn't worry too much about the solvents. If it's really oil-based grease, it's intended to lubricate metal-on-metal contact. Strong solvents would damage the metal, completely negating the effect of the grease. I doubt the solvents are anything more than mild detergents. I could be wrong, but I doubt there's more to it than that.

More concerning is that he's using a product rated for plumbing in an electrical environment. I had difficulty finding "Oatey Flanges Plumber's Grease," but they seem to have 2 current products, a 300 degree grease and a silicone grease. The 300 degree grease is oil-based, which means it's chemically organic, which means it's flammable. Even if he properly grounded it, any lightning strike would almost certainly ignite the grease, and I wouldn't rule out the grease igniting from the electrical activity going through his system.

The silicone grease is less concerning, but it's also an organic polymer.

In either case, there are products available to waterproof outdoor electrical connections. Using a plumbing product isn't a good idea.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#3
mrlew,

Personally, I never use the rubber boots because they tend to collect water unless they are sealed. I suppose they could be filled with silicone grease which is non-conductive, but any grease is messy. I used to use silicone RTV (Room Temperature self-Vulcanizing silicone rubber) which can be purchased at any auto parts store, used in automotives as a gasket dressing. However, I never use RTV on gaskets, I use a product called The Right Stuff which comes in an aerosol 'cheez-whiz' can. These days, I use it on coax fittings and plumbing projects too.

Jim
 

mrlewp87

DTVUSA Jr. Member
#6
On a related issue, building antennas has become a real hobby for me. I've yet to commit to the best in metals, due to price, so corrosion is a concern. When I'm making numerous connections, and sometimes mixed metals- alum., steel and zinc coated for ex., rarely copper, what could I use directly on the parts before tightening down? Meaning nuts, small bolts and washers, plus my own cut phase ligns- thin alum. strips. I have Ox Gard (name?), and a 2nd similar ooze. Are they more for an after-coating? Before running out of it, I was using a red anti-corrosion spray meant for battery terminals. Sure, it rinses off the exteriors, but I'm interested in the metal to metal surfaces and conductive properties.
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#7
mrlew,

Use stainless steel fasteners and RTV. Take a look at my photo albums here - you will see some of my antenna projects and construction techniques.

Jim
 

jackdashack

DTVUSA Jr. Member
#8
I'm gonna tell on my brother now. We live in different states, and nearly a year back I was serving up all sorts of advice (having just learned myself) on installing an OTA antenna. Trying to cover all the bases, including grounding and importance of good, clean connections, and preventing corrosion. He went a different way than anything I would've mentioned.
That's me brud! :applause:
 

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