K

Kato's 8

Well Known Member
Hey all,
I want to ask for opinions on use of blue RTV sensor safe on electrical connections. I'm using cheap molex connections for tail light and since those connection will be laying in bottom of the rudder cap, I thought a dab of RTV on the ends where wires enter the connector body could be sealed with this stuff to keep water out.
Is this acceptable or should I consider removing the stuff?

Thanks!!
 
An indecisive answer

I've been flying the RV-6A with a combo tail nav (white) light and strobe for ~9 years and never have had a problem with them bare but every connector on every wire bundle I can remember at McDonnell Aircraft in St Louis was potted with some form of rubbery compound that cured at room temperature. I may have just been lucky but I think you will be OK either way based on my limited experience.

Bob Axsom
 
I expect it would not hurt anything but would make the connector more difficult to work with. You can get electrical connection 'grease' in the aviation electrical department at Home Depot or Ace that will keep fluids out but won't glue up the connector. It is also known as dielectric grease. Mine is at the hangar, so I can't give you the maker or stock number but it shouldn't be hard to find near the electrical tools and small parts. Don't confuse it with contact cleaner, but I usually buy both at the same time.

If you are SURE you want to seal the wires into the connector body, I'd recommend liquid electrical tape.
 
Potting wires

"Liquid Electrical tape" is what you are looking for. We used it on all connections on the offshore race boats. Any automotive store should have it. If not try West Marine. Gene
 
Bob Nucholls on the AeroElectric list recommends potting connectors and pc boards with Sho Goo or E6000( 2 names for the same product). Available at Ace Hardware.

Jim Berry
Rv-10
 
Here's what a famous panel builder from Minnesota told me about Molex connectors: they can get wet, depending in where they are located, and cause problems, but they are very good at drying out. The weather sealed variety can still get wet, but are not good at all at drying out on their own. If you seal a Molex to make it 'dry', it will still most likely leak a little, but then won't dry out. Potting in sho-goo as BK recommends has more to do with mounting security than weather protection. Placing connectors where they are not subject to direct impingement from rain, and can drain well, will probably not cause more than very intermittent temporary problems in very wet conditions. Current will follow the path of least resistance through a copper conductor rather than jumping a damp gap to ground. After all, we are only talking about 12 volts in most cases.
 
All very good points and thankyou. I guess im ok with the RTV but could use shoe goo or amazing goop or dialetric grease ( which I already had and didnt even consider for some reason). But also, I never considered drying out time. Very good point too. I suppose these things would work just fine for years w/o any additional goop at all and maybe just a dab of dialetric on the connectors is all I need.

ThankYou!
 
How about a fairly long length of heat shrink tubing over the mated connectors? Possibly "waterproof enough", assuming the area isn't going to be drenched with rain, and very easy to remove/replace.

mcb
 
A litle advice

When using RTV on electronics, I found there are two types, one cures uses acetic acid and the other does not. The RTV for electrical stuff does not use acetic acid to cure. (I think it is acetic acid or whatever the call it now days). The wrong type of RTV will cause the electric connections to corrode. Don't ask me how I know.
 
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