[promocom]

In the old days they had a foaming blue cleaner that was great for cleaning switches tuners and tarnished connections... Is there a good product now for that or what are you using? Maybe something I could get in a hardware store?

[Chas]

Blue Showers...

There is risk of phenolic penetration and leakage. Blue showers was intended to polish the contacts as it had grit in the mix for TV tuners.

In a radio, if the circuit is not known, there could be B+ switched, a cleaning product could cause leakage to the shaft and burn out the wafer.

I use 91% alcohol and an acid brush, back up the switch with a clean cotton rag to soak up excess and contaminates.. Massage the brushing all the way around each side of the wafer, then turn the switch in the opposite direction, clean again. Blow dry thoroughly as the alcohol will chill and cause condensation, warming gently the sections will thoroughly dry. Alcohol will remove all the old rosin residue and any other contaminate. Look at the actuation of the contacts each contact should rise/fall as the connection is made/broken, this is a self-wiping action. Black silver oxide still conducts.

De-Oxit applied with a stylus to only the contacts will help, never saturate the phenolic wafer as this will cause leakage.

GL

Chas

[mikethedruid]

We used to use carbon tetracloride. It was GREAT for cleaning switches and also potentiometers. It was quite inert so it didn't destroy the wafers, or the resistance element of the pots. It evaporated VERY fast and was non-conductive. I had a bottle for years which I used until it finally ran out.

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[promocom]

Good to know, I'll get some high strength alcohol and give it a go. thanks!

[MrFixr55]

When I was a kid, the local jobber sold 2 products, the afore mentioned "Blue Shower" that you can bathe the control in and "Blue Stuff," an abrasive (I believe) cleaner and lube that you had to judiciously and carefully to contacts to prevent detuning.

In the BioMed Shop at the hospital I worked at in my senior year at high school and freshman year at college, we used several Miller-Stephenson products such as "Contact Re-Nu". The product had a hose and brush wand that attached to the can, was very handy. M-S also made a PC Board wash and a flux remover