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Old 14th January 2011, 08:11 PM   #1
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Default Cleaning up an old ST-70 chassis

Hey,

I could have sworn I saw a thread about this already, but I couldn't find it, so I apologize in advance if this is redundant here.

I'm just wondering what products and/or processes to use to clean up an old ST-70 chassis. It's in pretty good shape, only a slight dusty texture that can probably mostly be removed.

It's quite yellowed. Does it have some sort of varnish finish on the steel? And of course I would like to leave the text intact.

Your advice please!

..Todd
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Old 14th January 2011, 08:44 PM   #2
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IIRC,they were nickel plated. I've used Happich Simichrome polish on mine with good results. I found it at the local grocery(!?) store for about $5 a tube.

Happich Simichrome Polish - Metal Polish - Only $7.99!
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Old 15th January 2011, 02:47 AM   #3
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There are a couple of posts over at DIYtube's ST-70 forum that mention Blue Magic Polish available at your local Pep-Boys, Kragen, etc.
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Old 15th January 2011, 03:19 AM   #4
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Thanks guys. I'll look around and see what's available here. I've never heard of or seen those products (or stores). Not surprising considering y'all are foreigners.

..Todd
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Old 15th January 2011, 05:15 AM   #5
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Hey Todd, I've used Autosol Metal Polish for a long time. Don't think you'll find it at any of the big chain stores, may one of your local auto parts stores. I searched canadiantire and got nothing.

jeff
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Old 15th January 2011, 07:53 AM   #6
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Thanks Jeff. There are a couple of auto parts dealers nearby. I'll check them out.

..Todd
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Old 15th January 2011, 08:00 AM   #7
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Believe it or not, for age grime that seems to affect/effect the old chassis metals, I actually used what all the stock manufactures use to recommend first before polishes, ammonia.
On a couple old vintage chassis, it really worked. Saved $$ too...
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Old 15th January 2011, 05:03 PM   #8
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I cleaned mine with non-chlorine bathroom cleaner on a paper towel. Scrubbing bubbles formula, but I use the generic stuff from Family Dollar store. Ethylene glycol monbutyl ether. Got a pick and pushed the towel around all those resistors and capacitors on the PCB too. Made the color dots on those domino caps look good again. Let it dry for a couple of days before turning on as this stuff is water based. Make sure caps are below 25 VDC before touching metal or wiring.
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Old 15th January 2011, 06:34 PM   #9
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Rockmore,
Yup, that makes sense. I've been reading that ammonia is good for cleaning nickel plating. Then some nickel specific polish afterwards.

indianajo,
I suspect it's the ammonia that is doing the work in your suggestion too.

I will be stripping this down and replacing all the sockets, switches, caps, ins and outs, etc. And I won't be keeping the driver board, so I won't bother cleaning it.

..Todd
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Old 15th January 2011, 08:01 PM   #10
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No ammonia or bleach in F.D bathroom non-chlorine cleaner. I had almost no metal corrosion, but it is amazing how much organic fuzz 1 man and 1 cat shed over 20 years. Cleaned it about 1975, not as well. ST70 didn't have any arcing yet, but it was just a race between the worn out power tubes and the organic coated sockets & pcb's which caved first. Tubes faded first, I'm saving up for 4 more 6CA7. My 7199 are still fine, the 4 paper caps are replaced with film, 4 plate resistors are metal film, why change is my philosophy.
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Last edited by indianajo; 15th January 2011 at 08:05 PM.
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