I finally changed my mind about using thermal paste on avionics connectors

Old timer at the hangar in Denver named Rick always said put a dab of thermal paste on Cannon plugs before mating them. I thought he was crazy, figured that stuff was just for computers and would cause shorts. Been doing this job 8 years without it and never had an issue, so I ignored him. Then last month a weather radar connector on a King Air kept throwing intermittent errors. Pulled it apart and saw corrosion on the pins that only showed up in certain humidity. Rick walked over, cleaned it up, put a tiny smear of thermal paste on the dielectric, and the errors stopped cold. It seals out moisture better than anything I tried. He was right all along. Anyone else use thermal paste on connectors or am I the last guy to figure this out?

2 comments

2 Comments

wells.reese8d ago

Gentle correction there... thermal paste and beeswax aren't really the same thing. Thermal paste is meant to transfer heat, while beeswax is just a moisture barrier. Rick's trick works because the paste fills tiny gaps in the connector's dielectric, keeping water out without bridging the pins. Beeswax on coax threads is more about preventing galvanic corrosion and keeping the connection from seizing up. Both work, but for different reasons. Just don't swap one for the other or you might end up with a sticky mess that doesn't fix anything.

gibson.seth8d ago

And you know what's funny, I had a similar thing with a buddy who swore by using a little beeswax on the threads of coax connectors for his ham radio setup. I always thought it was some old-school wives' tale until I saw the difference it made keeping the salt air out at the coast. Now I'm half tempted to start waxing all my own connections just to see what other old tricks actually work.