Pioneer Silver Era Knobs- SX-780- Refinishing Tips?

Arthur Smith

Super Member
Hi, I have noticed on my 780 knobs that the silver paint, or plating, or whatever they used 40 years ago, has started to fade off, revealing a whitish plastic underneath. Is there an "easy" way to refinish the knobs that members here have used with success? Thanks, Arthur
 
The switch caps and potentiometer knobs are aluminum. These were hard anodized to prevent oxidation and dulling. If the anodized layer is worn through, the aluminum will turn a dull white/gray color. These can be either re-machined or polished, then anodized again or covered with a clear coating while they are still bright.
 
The switch caps and potentiometer knobs are aluminum. These were hard anodized to prevent oxidation and dulling. If the anodized layer is worn through, the aluminum will turn a dull white/gray color. These can be either re-machined or polished, then anodized again or covered with a clear coating while they are still bright.
Polished with what, exactly?
 
Polished with what, exactly?
Your not going to be able to polish them. They are anodized, that bakes deep into the aluminum. It's pretty hard to strip ALL the anodizing off but can be done. A professional service can strip and reanalyze them but would be cheaper to just buy better ones.

If I tell you what strips the anodizing, you'll probably do it but then the knobs will just oxidize looking worse than what you have now.

Someone probably already soaked them in a cleaner that harmed the coating turning them whitish.
 
What if I just find a chrome-like paint, and shoot them with that? I'm not super picky, but I just want them to look better.
 
What if I just find a chrome-like paint, and shoot them with that? I'm not super picky, but I just want them to look better.

Most paint will not stick to aluminum without appropriate preparation and priming--especially in the existing condition--so an $8 can of spray paint is not likely going to "fix" anything.
 
I have no idea if this will even remotely work, but I'll throw it out there... I would not try this with one of your knobs without testing it on something that you don't mind throwing away, but if you know someone that polishes brass for reloading ammunition, try dropping it in one of the drum type machines (no chemicals, just the dry abrasive) and let it run for a little while. I would guess if it turns out nice, you would have to seal it with some sort of clear-coat to protect it when done. I guess the ones for polishing stones are about the same, but I don't know the grit levels of abrasives used in them.

EDIT--brain fart when I posted--the real name of the machine is a "tumbler"--used for polishing brass, jewelry and stones.
 
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Polish the aluminum with a rouge wheel, then coat or anodize it immediately, before oxidation can occur and dull them again. Metal finishers do it all the time.

You can also polish them then apply acrylic or urethane clear coat, but it is not as durable as the anodized surface.

http://lmgtfy.com/?q=anodizing+aluminum
 
I’ve seen Technics SA-300 (200, 400, etc) lever knobs do that, but they just seem to be painted. I don’t think I have ever seen SX-780 knobs with that issue.
 
company called caswell sells a home anodize kit,tried it once in my motorcycle days. if you like to fiddle around. i wouldnt send it out as commercial polishing/polisher's will be expensive and make the ebay prices seem quite reasonable. ebay is what i would do.
 
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