[Arran]

I would remove the dial scale and wash that whole chassis with a solution of about two tablespoons of TSP in a gallon of hot water. The solution will clean all of that dirt and oxidation off the chassis and the aluminum cans, though sometimes removing the cans makes it easier to clean the chassis. I pour just enough of the solution over the chassis to cover it and start scrubbing in every nook and cranny with a toothbrush, if that isn't enough I pour some more over it. After the solution has been on there and worked around for five to ten minutes I then rinse off with liberal amounts of hot water, then I place the chassis in a warm place to dry with lots of air circulation and leave it there for several days.
I've explained this approach to people several times but they are often horrified, but water is only really a problem with electrical equipment if it's wet and is energized, or it stays wet or damp for an extended period of time. The funny part was one of the guys who was horrified by my use of TSP and water was someone who advocated using brake cleaner, if you want to talk about aggressive solvents that stuff is up there with acetone. The one thing I would be careful about is not to submerge the power transformer, but this is more like a shower rather then a bath, and on this chassis it looks like it would be difficult to get any water in the windings by accident.
Regards
Arran

[jontz]

Codefox,

I might get adventurous enough on the next radio to try that, but the ultrasonic really did a nice job of cleaning up the plates. Thanks for the warning as well. I know better than to put anything flammable in an ultrasonic, but I do appreciate you making sure!

Arran,

I believe I will try your method for cleaning up the chassis. I have just one question though. Are you talking about Trisodium Phosphate when you say TSP?

It is funny how some people are afraid of water and electronics. I assume that most of them have dropped a cell phone in the sink/pool/toilet and that's the only experience they have. Thanks for the suggestion of how to clean this chassis up, I do appreciate it.

[morzh]

Things I would not use on any metal (unless this is my purpose to use exactly those) are acids and alkali. This is regarding the vinegar.
Aluminum gets a bit dissolved in acids, and when storing acid foods it is not recommended storing them in aluminum containers unless one has a serious lack of it in his blood and wants to replenish it.
And vinegar is stronger by itself than when it is diluted in food.

However small part of the cap's plates it will dissolve, this may change the capacitance.
Of course some caps have steel plates. Still not sure it is good.

Solvents / fuels are neutral.

And, of course, don't use them at home,, use them outside, away from the house, and ultrasonic is not needed - just use a brush.


PS> Having said this, since my cap in my Philco was simply dirty but not grimy, I successfully washed it in my dishwasher. It was not aluminum so it did not darken.

[Arran]

Yes, tri sodium phosphate, I don't know why I forgot to spell it out, it's available in every paint store, hardware store, and even places like Walmart.
It's pretty much like a strong soap, I've been using it for years with no real troubles, occasionally a rusty screw if it was an unplated screw and didn't dry quick enough. I would also recommend oiling the threads on any trimmer screws before and after the chassis gets washed and dried. For whatever reason I have never got around to posting any pictures on here, something I will have to figure out, so give it a try and show everyone how it came out.
Regards
Arran