[DKinYORKpa]

After the control worked fine for weeks during the restoration, one day the ON/OFF wasn't switching. OK, no prob, probably needs some contact cleaner. Gave her a shot, worked the switch back and forth and 10 minutes later I tried it and it worked. 1/2 hours later, no good again. So I repeated that procedure 4 or 5 times. Same results. So with nothing to lose, I gave it a shot of WD-40. It has worked fine now for 2 days. Thoughts anyone?

[Phlogiston]

This happens often on old 30s switches. Sometimes the spring inside has gotten weak, but, more often the contact has worn out. Twisting bending and spraying sometimes fixes it (for the next few years) sometimes till the cleaner solvent drys out.

WD 40 is fine for the switch. I would not get it inside the vol control on a Philco of that vintage - or any radio that uses a coated resistor - only use the "green" Deoxit. I don't rember the #, but it says safe for plastics.

[Eric T]

I stay away from WD-40 except under a car hood or to get sticker glue off of something. It has a tendency to turn into gummy crud after a while. My dad lubricated a pistol with it once, and 6 months later the slide wouldn't hardly move.

I prefer silicone or teflon-based lubricants for electronics and small machinery.

[DKinYORKpa]

I stay away from WD-40 except under a car hood

I'm with you, but the contact cleaner was doing nothing. So before I ordered a new control, I tried the WD-40 just to see and so far it's working. But there's nothing to lubricate there.

[TA Forbes]

WD is ok, but cleaners specifically made for cleaning electronic equipment are better. Try getting a hold of some Deoxit, and you will never go back to anything else.

[Ron Ramirez]

Try getting a hold of some Deoxit, and you will never go back to anything else.

Ditto!

[Arran]

Don't use silicone or teflon based lube in a switch, that may gum up the contacts and then you will have to take the switch off again to get it working. Likely the WD dissolved some old grease and crud from the contacts or the mechanism, this is a common problem I run into with farm battery radios that have sat around disused for decades, I often take the whole control apart and soak the parts in mineral spirits to get the old grease and oil out.
Regards
Arran