How to clean and old Air Variable Cap?

[Naysayer]

Found a V Air cap on eBay and ordered it. It's looks to be in good condition for it's age but oxidation is evident. What can I use to treat the aluminum metal?

 

[loosecannon]

i can't speak from experience but i tend to trust what Nomad Radio says, and i just read a thread where he used Air Conditioning coil cleaner on a variable capacitor.

It would be best to consult him before trying it IMO.
LC

 

[Naysayer]

A few months ago I serviced 2 large window AC units and still have more of the coil cleaner left. It should have occurred to me. Yes, I suspect you're right and it should work well. Thanks

 

[nomadradio]

The air conditioner coil cleaner we've used for decades is mostly phosphoric acid, water and blue dye. Does a number on aluminum, brass and copper. Beware using it on anything silver plated. It will scrub the silver right off the surface. Called Lundmark Coil Cleen. There are others, but that's the one we use.

73

 

[Naysayer]

New cap delivered yesterday. Removed old one, disassembled and cleaned new one best I could with Q-tips and aluminum cleaner (Noxon green). See how it looks in the morn.

New air Variable Load cap is a 2 section: 7-52 and 13-155pF. Same HV spacing /series for 3kv by Johnson I think. Low enough for 10 but a 200pf spread when padders switched in.

Before disassembly, it was working thru to 40 but tuning was tedious. Have a small Kilovac latching for adding one Tune padder as the vacuum cap only goes to 105pF. The max Tune C for my tube set is less than 400 for 80m.

Record breaking heat in NYC last few days. So far, no complaints re:qro. City hamming has some unique concerns.

 

[VMC]

I had some success with taking some air variable trimmers to a jeweller and having him toss them in the ultrasonic cleaning tank.