MTFCA Forum

Okay. I tried to start my T when I noticed the key switch connection to BATT was sloppy in that I had to jiggle the key for the coils to buzz so I decided to check the switch. I gently pried up the 4 tabs and exposed the innards. The contacts were very dirty and one of the two contacts on the small inner ring was bent flat against the fiber base while the other one was raised about 3/16” above the fiber base with the rounded contact raised a little higher. Using 600 sandpaper, I cleaned the contacts and bent the one flat contact up and out, identical to the other one. With the contacts clean and re-tensioned, My question is, before reassembly, I would like to lubricate the contacts and components. Is this advisable and, if so, what is the best non-conducive lubricant to lube the contacts with so they will turn easily and make a clean connection with each contact? I was thinking Vaseline would be a good inert lubricant for this purpose. Is there any chance it may cause a short between the contacts? What say you? Jim Patrick

If I didn't know better I would use radio tuner spray.

The two fiber rings rotate on the base of the cup. Really no need to lubricate but a small smear of silicon grease (plumber's or even dialectic grease) can be used on the raised portion of the bottom of the cup that the rings rotate on.. Do not use graphite on anything (in the key slot etc) it can cause a short. The tumblers get sticky /dirty so some lub drop of oil there is okay. Put it on the key and turn. A loose key may be a sign of a cracked tumbler. The originals were made of a pot metal. You can see one in the tumbler

Thank you. Since no one advised against it, I went ahead and dabbed Vaseline on the raised convex contacts and on the concave contacts imbedded in the fiber backplate and squirted a little WD-40 into the tumblers then reassembled the switch. It is much tighter now and operates smoothly with no play and I am confident that it will work as intended with much better connections than it had before I started. When I get it wired up and installed, I will give it a try. Thank you. Jim Patrick

Jim, Before you reassemble your switch you might want to anneal those tabs that hold it together, if you don't they tend to crack and/or break off. Jim

I do not know the extent that it conducts current, but petroleum jelly is considered conductive when put into an electrical circuit and additionally has a low melting point. Not a combination that I'd be comfortable with on a pressed paper switch.

I myself would not consider applying it to anything which would soak it up into the paper backing of the switch and potentially cause parasitic draw down to the battery. I once experienced a T which would run it's battery down in a week and found it to be due to a pinched wire in oil-soaked insulation. I actually discovered it by accident when I tested the electric potential of the coolant in the radiator to ground. YIKES!! No wonder my aluminum radiator mascot was dissolving before my eyes!

Finding the pinched wire and replacing the loom stopped the destruction of my mascot and stopped running the battery down.

Might want to consider how much you applied and then rethink this...

Jim, 2 hours and 11 minutes between your first posting and your decision to use vaseline doesn't give any of us much time to contribute. Some of us old farts take that long just to wake up!
Give us a break.

Allan from down under.

LOL! Okay Alan. But it was such a pretty day today, I was anxious to take advantage of the beautiful weather and daylight. I just dabbed the Vaseline on each contact. I didn’t slather it on the pressed paper backing plate which could have joined all 7 of the contacts with a possibly conductive path at between them. I have always been Leary of the conductivity of greases and lubricants so, naturally I try not to create a possible path between contacts by using as little as possible and never use anything containing graphite. Jim Patrick