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Main Forums => The Roundtable => Topic started by: Leatherneck on May 05, 2008, 01:34:53 PM

Title: Cleaning Tarnished Copper Wire
Post by: Leatherneck on May 05, 2008, 01:34:53 PM: How?

Some of the copper I've been hoarding for years came in the form of heavy-like 2 gauge-stranded four conductor wire. I "stored" it outside on the ground until cutting it up in 3-foot sections which I strip while watching the evening news in the shop. Rain water permeated the whole 200 feet over the years, and the stranded wire comes out clean but tarnished dark gray.

As I strip each bit I throw it in a bukkit. What liquid works best to simply take off the tarnish?

Bright copper wire brings a bit more at sanford & Son.

TC
Title: Re: Cleaning Tarnished Copper Wire
Post by: charby on May 05, 2008, 01:36:44 PM: Tarn-X

http://www.jelmar.com/TarnXbasic.htm
Title: Re: Cleaning Tarnished Copper Wire
Post by: Brad Johnson on May 05, 2008, 01:37:07 PM: Quote
Bright copper wire brings a bit more at sanford & Son.

Why? Copper is copper, patina or no.

Brad
Title: Re: Cleaning Tarnished Copper Wire
Post by: Leatherneck on May 05, 2008, 02:01:31 PM: Because junkyard dealers try to buy low and sell high.

I'm thinking common household chemicals like vinegar or something cheap like muriatic acid? Or do I want a non-acid solution? I can't remember enough chemistry. I believe the tarnish is either copper sulfide or copper oxide.

Chemists up!

TC
Title: Re: Cleaning Tarnished Copper Wire
Post by: charby on May 05, 2008, 02:22:07 PM: google-fu brought up this website

http://www.repair-home.com/Cleaning_Copper.html
Title: Re: Cleaning Tarnished Copper Wire
Post by: Leatherneck on May 05, 2008, 02:33:36 PM: Huh. I hate it when Google provides the answer. Thanks though. That site seems to confirm my suspicion that acid is the answer. Yes?

TC
Title: Re: Cleaning Tarnished Copper Wire
Post by: charby on May 05, 2008, 02:39:03 PM: I remember dropping pennies in HCl and watching the copper get bright and the zinc dissolve away.
Title: Re: Cleaning Tarnished Copper Wire
Post by: Leatherneck on May 05, 2008, 02:42:19 PM: So that's muriatic acid? Or is that sulfuric?

Oh crap--I'm gonna have to find the chemistry books...

TC
Title: Re: Cleaning Tarnished Copper Wire
Post by: Sergeant Bob on May 05, 2008, 02:47:52 PM: I know that you can clean silver using a container lined with aluminum foil, then put in baking soda, then boiling water. It's an electrolytic reaction, the foil will end up with all the tarnish on it. Don't know if it works on copper though.
Title: Re: Cleaning Tarnished Copper Wire
Post by: French G. on May 05, 2008, 04:01:59 PM: Maybe try the cheapest generic cola type soda you can get or try the vinegar. Both will work, need a good rinse afterward or tarnish will return.
Title: Re: Cleaning Tarnished Copper Wire
Post by: 280plus on May 05, 2008, 04:20:20 PM: I'm not sure it's necessary LN. As long as there's no paint solder or insulation I believe it is considered clean copper even though it's tarnished. Call em and ask!
Title: Re: Cleaning Tarnished Copper Wire
Post by: Harold Tuttle on May 05, 2008, 04:23:49 PM: lemon juice & salt
Title: Re: Cleaning Tarnished Copper Wire
Post by: charby on May 05, 2008, 05:20:31 PM: Quote from: Leatherneck on May 05, 2008, 01:42:19 PM
So that's muriatic acid? Or is that sulfuric?

Oh crap--I'm gonna have to find the chemistry books...

TC

HCl= Hydrochloric acid
Title: Re: Cleaning Tarnished Copper Wire
Post by: Nick1911 on May 05, 2008, 05:29:58 PM: Quote from: Charby on May 05, 2008, 04:20:31 PM
Quote from: Leatherneck on May 05, 2008, 01:42:19 PM
So that's muriatic acid? Or is that sulfuric?

Oh crap--I'm gonna have to find the chemistry books...

TC

HCl= Hydrochloric acid

Hydrochloric acid = muriatic acid
Title: Re: Cleaning Tarnished Copper Wire
Post by: DJJ on May 05, 2008, 06:11:55 PM: IIRC, vinegar and baking soda was what we used in elementary school science fairs to shine up old pennies. These were real copper, but they weren't so bad as to be gray.
Title: Re: Cleaning Tarnished Copper Wire
Post by: Bogie on May 05, 2008, 06:24:02 PM: This may seem a little strange, but get some industrial ammonia down at Ace Hardware... 10% stuff.

Dunk it, hose it, you're done.

Yeah, it'll eat a little. That's why you hose it.

And you can use the ammonia on your floors.
Title: Re: Cleaning Tarnished Copper Wire
Post by: crt360 on May 05, 2008, 08:00:35 PM: Tobasco sauce.
Title: Re: Cleaning Tarnished Copper Wire
Post by: Larry Ashcraft on May 06, 2008, 05:21:08 AM: Phosphoric acid. Just get some "Lime Away". Phosphoric is the active ingredient.

I use the stuff on really grungy range brass, just make sure you rinse it well afterwards.
Title: Re: Cleaning Tarnished Copper Wire
Post by: GigaBuist on May 06, 2008, 08:22:49 AM: The local brewery has a copper covered bar. They use vinegar to keep it shiny IIRC.
Title: Re: Cleaning Tarnished Copper Wire
Post by: Jamisjockey on May 06, 2008, 11:51:56 AM: Quote from: Leatherneck on May 05, 2008, 01:33:36 PM
Huh. I hate it when Google provides the answer. Thanks though. That site seems to confirm my suspicion that acid is the answer. Yes?

TC

Much more fun to ask here!
Title: Re: Cleaning Tarnished Copper Wire
Post by: 280plus on May 06, 2008, 04:59:49 PM: I'm tellin' ya, before you go through all that double check with the scrap yard.