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CLEAN COPPER PIPE

Posted: Tue Mar 24, 2009 11:53 pm
by stillvodka
I have some 2.5 -2'' copper pipe, it's all gone green oxidized inside, I am finding it hells work trying to remove it, just cant get inside the tubing properly, Have anyone got a good idea how to clean it out, I was thinking of soaking it in Vinegar , but not sure if it could damage the copper.

Re: CLEAN COPPER PIPE

Posted: Wed Mar 25, 2009 12:04 am
by eternalfrost
Ive never had it to the point where its GREEN but for normal tarnishing a mixture of an acid and a salt will make it blindingly shiny.

some choices are lemon juice or vinegar for the acid and table salt of baking soda for the salt. mix it up into a paste and spread it on and leave it sit awhile then just rinse off.

as to the OP, vinegar in no way will harm anything

Re: CLEAN COPPER PIPE

Posted: Wed Mar 25, 2009 12:47 am
by Ayay
Do the acid soak and then put a stainless pot scrubber on the end of a 1/4" iron rod or 1/2" wood dowel. If the rod is 1.2m long you can work from both ends with the rod spun in a drill (variable or slow speed!). Use plenty of rinsing water while scrubbing. It may need a few acid soaks and scrub/rinse to get it clean.

Re: CLEAN COPPER PIPE

Posted: Wed Mar 25, 2009 8:40 am
by theholymackerel
Was all the pipe green, or just the inside?

Copper, when given enough time, will oxidize a beautiful blue-green colour. But I've been told that it takes a good one hundred years to obtain that colour. Copper after about 15 years or so, will oxidize to a nice honey-brown colour, and then after a hundred or so years ya get the blue-green, or green.

If yer copper isn't old enough to have gotten it's colour naturally then it was "force oxidized" with chemicals. Some artists that work with copper use these chems to cheat and get the colour right away. I'd check to make sure yer copper isn't coated with somethin' nasty.

Re: CLEAN COPPER PIPE

Posted: Wed Mar 25, 2009 10:19 am
by 1fourme
Unless you know for a fact... that the pipe has only been used for potable water, don't use it. As a plumber I have sent alot of pipe to the scrap yard that was used for chemicals, both toxic and highly hazardous....

Re: CLEAN COPPER PIPE

Posted: Wed Mar 25, 2009 11:05 am
by stillvodka
Thanks for the replies and advice,
The copper pipe came from a factory wash rooms, I am sure only soapy water has been through them, they are old pipe but really solid and in good nick, just got this green oxidation on the inside, I put some flux cleaning salts through a pipe to day and it removed the oxidisation quite easily after leaving for half hour, came up like new, but these cleaning salts are expensive, one of the ingredients of the salts is citric acid, this was something Eternal Frost said about, so I am going out tomorrow and get some pure lemon juice and half gallon of vinigar, and give um a good soak :)

Re: CLEAN COPPER PIPE

Posted: Wed Mar 25, 2009 11:24 am
by myles
I have used both acid drain cleaner and normal pluming flux to get the colour off old pipes before. Dont leave either on for too long though.

Re: CLEAN COPPER PIPE

Posted: Wed Mar 25, 2009 2:29 pm
by bourbonbob
A few vinegar runs should remove it. :idea:

Re: CLEAN COPPER PIPE

Posted: Thu Apr 02, 2009 5:39 pm
by LWTCS
cylinder hone on a drill moter. Then the wash solution for good measure

Re: CLEAN COPPER PIPE

Posted: Sat Apr 04, 2009 6:55 am
by violentblue
clean cotton rag on a stick, attach to a drill, dampen the cloth and add a little scouring powder. spin medium speed back and forth till its got a nice polish.

then do it again without the scouring powder. rinse with water.

Re: CLEAN COPPER PIPE

Posted: Sat Apr 04, 2009 9:34 am
by minime
I got a used 3" copper plumbing stack for free last year. I filled a shallow tray with muriatic acid and laid the pipe in it intending to turn it as the oxidization disappeared. Unfortunately the acid didn't even touch the green stuff after a week of soaking. Since I didn't need the pipe anyway I gave up and threw it in the storage shed. If you do find a good way to clean it up I'd be happy to try it too!

Re: CLEAN COPPER PIPE

Posted: Sat Apr 04, 2009 10:08 am
by Ugly
cleaning stubborn copper totally clean is possible.

Make a weak acid solution with vinegar or muriatic that you can immerse the entire pipe in, add a little salt and a dash of sugar or little bit of anti freeze. Apply the positive electrode of your battery charger to the copper pipe. Attach the negative electrode of your batter charger to any kind of scrap metal and stick the scrap in the solution not touching the copper pipe. The weak acid will turn blue as it begins dissolving the copper and it's oxides and the pipe will start coming clean. The scrap will form a heavy layer of brown gunk as it attempts to electroplate itself so knock the crap off it once in a while. Keep at it, the pipe will soon sparkle.

Don't do this with soldered metals, will leach the tin out of the solder in very short order.

Re: CLEAN COPPER PIPE

Posted: Sun Apr 05, 2009 3:27 am
by minime
Ugly wrote:cleaning stubborn copper totally clean is possible.

Make a weak acid solution with vinegar or muriatic that you can immerse the entire pipe in, add a little salt and a dash of sugar or little bit of anti freeze. Apply the positive electrode of your battery charger to the copper pipe. Attach the negative electrode of your batter charger to any kind of scrap metal and stick the scrap in the solution not touching the copper pipe. The weak acid will turn blue as it begins dissolving the copper and it's oxides and the pipe will start coming clean. The scrap will form a heavy layer of brown gunk as it attempts to electroplate itself so knock the crap off it once in a while. Keep at it, the pipe will soon sparkle.

Don't do this with soldered metals, will leach the tin out of the solder in very short order.
Excellent! I'll give that a try........

Re: CLEAN COPPER PIPE

Posted: Sun Apr 05, 2009 12:36 pm
by nh_yankee
The safest way to clean copper is to use vinegar and table salt (NaCl) and aluminum foil. If you want to clean the outside of the pipe, loosely wrap the pipe with foil, immerse in the vinegar and sprinkle the salt. For the inside stuff the foil into the pipe for the full length of the pipe being cleaned and immerse in vinegar and salt solution. Rinse very well after cleaning. (this also works for silver and pennies that are tarnished)

Danger, Science Theory:
The salt acts to move the O2 or SO2 (etc) chemically bonded to the Cu toward the Al just like it would using a battery charger or a battery. Aluminum is one of those very reactive metals and "demands" to be "fed" in this reaction. All that we have done is made a battery.

Note: Any other DILUTE acid could be used but I would not suggest Sulfuric or Sulfurous acid

Re: CLEAN COPPER PIPE

Posted: Sun Apr 05, 2009 1:12 pm
by Ugly
Basically the same theory as what I just described. Just that using it as the anode in electroplating will actually work sometime before death occurs. The aluminum foil might generate all of what.. half a volt? as a battery cell . Just guessing. On a piece of pipe that big, a puppy could be born and die before it comes clean at that voltage.

Just saying.

Re: CLEAN COPPER PIPE

Posted: Mon Apr 06, 2009 4:11 am
by billy_bob_95
I use a mixture of muractic acid and water with steel wool to clean the out side of the copper pipes, but not the insides of the column. I would try the vinegar and water for the inside. Might piece the column together and cook it out with vinegar and water are even a simple sugar wash. Alcohol vapors are amazing at cleaning copper.

Re: CLEAN COPPER PIPE

Posted: Mon Apr 06, 2009 6:29 am
by junkyard dawg
http://users.eastlink.ca/~pspencer/nsae ... lysis.html" onclick="window.open(this.href);return false;" rel="nofollow

Re: CLEAN COPPER PIPE

Posted: Mon Apr 06, 2009 3:42 pm
by junkyard dawg
When I got back from town I put one of these together. So far its done incredible work on a rusty cast iron lid.

Re: CLEAN COPPER PIPE

Posted: Tue Jul 06, 2010 2:29 pm
by jackalope
minime wrote:
Ugly wrote:cleaning stubborn copper totally clean is possible.

Make a weak acid solution with vinegar or muriatic that you can immerse the entire pipe in, add a little salt and a dash of sugar or little bit of anti freeze. Apply the positive electrode of your battery charger to the copper pipe. Attach the negative electrode of your batter charger to any kind of scrap metal and stick the scrap in the solution not touching the copper pipe. The weak acid will turn blue as it begins dissolving the copper and it's oxides and the pipe will start coming clean. The scrap will form a heavy layer of brown gunk as it attempts to electroplate itself so knock the crap off it once in a while. Keep at it, the pipe will soon sparkle.

Don't do this with soldered metals, will leach the tin out of the solder in very short order.
Excellent! I'll give that a try........

I know this is an old post and it doesn't look like Minime has been on since May so hopefully someone else can lend some advice.. Has anyone tried this electroplating the green oxidation from inside a pipe.

Perhaps I should tell you what I am up against. The three inch pipe I have has a hard layer of green oxidation inside. The pipe was removed from an older house and it was the vent stack for the gas water heater. I suspect the buildup is a combination of heat / moisture / open air flow to the elements and a byproduct of burning NG for a period of maybe 30 years.. Not chemicals.

Things I have tried
Coarse steel wool ziptied to a dowel rod and chucked in a drill, used both dry and wet. Also used an abrasive powder called Barkeepers friend. Didn't work.

Soaked in a 50/50 vinegar / water and a pinch of salt bath overnight. It made the outside shiny and somewhat loosened up the oxidation inside the pipe. However I don't have all decade to wait on it.

Dropped a railroad spike in the solution hooked to the negative on a 6v battery and pipe to the positive. Not much of a change overnight. The wall of the pipe closest to the spike was cleaner though.


Idea...

Make a trough barely wider and taller than the pipe. Immerse the pipe in the mild acid solution and place a length of iron reinforcement bar through the center of the pipe resting it's ends on wooden blocks so as not to touch the pipe. Negative to the reinforcement bar and positive to the pipe. However this time I plan to use a 12v battery charger. The question is on what setting?


Oh BTW. Very nice site you guys have here. I have been reading and lurking for about 4 months now getting all the reading done. And to tell you the truth i probably don't know the 10th of it... :( ... Anyways. Thanks for the help. Everything is appreciated. :D

Re: CLEAN COPPER PIPE

Posted: Wed Jul 07, 2010 10:35 am
by NineInchNails
jackalope wrote:
minime wrote:
Ugly wrote:cleaning stubborn copper totally clean is possible.

Make a weak acid solution with vinegar or muriatic that you can immerse the entire pipe in, add a little salt and a dash of sugar or little bit of anti freeze. Apply the positive electrode of your battery charger to the copper pipe. Attach the negative electrode of your batter charger to any kind of scrap metal and stick the scrap in the solution not touching the copper pipe. The weak acid will turn blue as it begins dissolving the copper and it's oxides and the pipe will start coming clean. The scrap will form a heavy layer of brown gunk as it attempts to electroplate itself so knock the crap off it once in a while. Keep at it, the pipe will soon sparkle.

Don't do this with soldered metals, will leach the tin out of the solder in very short order.
Excellent! I'll give that a try........

I know this is an old post and it doesn't look like Minime has been on since May so hopefully someone else can lend some advice.. Has anyone tried this electroplating the green oxidation from inside a pipe.

Perhaps I should tell you what I am up against. The three inch pipe I have has a hard layer of green oxidation inside. The pipe was removed from an older house and it was the vent stack for the gas water heater. I suspect the buildup is a combination of heat / moisture / open air flow to the elements and a byproduct of burning NG for a period of maybe 30 years.. Not chemicals.

Things I have tried
Coarse steel wool ziptied to a dowel rod and chucked in a drill, used both dry and wet. Also used an abrasive powder called Barkeepers friend. Didn't work.

Soaked in a 50/50 vinegar / water and a pinch of salt bath overnight. It made the outside shiny and somewhat loosened up the oxidation inside the pipe. However I don't have all decade to wait on it.

Dropped a railroad spike in the solution hooked to the negative on a 6v battery and pipe to the positive. Not much of a change overnight. The wall of the pipe closest to the spike was cleaner though.


Idea...

Make a trough barely wider and taller than the pipe. Immerse the pipe in the mild acid solution and place a length of iron reinforcement bar through the center of the pipe resting it's ends on wooden blocks so as not to touch the pipe. Negative to the reinforcement bar and positive to the pipe. However this time I plan to use a 12v battery charger. The question is on what setting?


Oh BTW. Very nice site you guys have here. I have been reading and lurking for about 4 months now getting all the reading done. And to tell you the truth i probably don't know the 10th of it... :( ... Anyways. Thanks for the help. Everything is appreciated. :D
I would use a trash bag folded up several times and use it as a cap over one end of your pipe. Then secure it using a hose clamp so that the end of the pipe is water tight. I'd fill it approx 1/2 way with water then pour some Muriatic acid (from the hardware store) inside the pipe. Now all you have to do is top it off with more water. Leave it for a few hours and it should strip it clean.

If diluted acid doesn't work then you could try using acid straight out of the jug and pour it through (pipe set at an angle). I'd try at least a test spot first to make sure that it works. You can use a bucket on the other end of the pipe to collect the acid as you pour it. You might have to pour it through several times and rotate the pipe a bit between each pour to ensure that you get every square inch of the interior.

I've been using Muriatic acid to strip the interior of my stainless steel pipes that had a BUNCH of mineral buildup inside them and it worked like a charm. I have also been soaking my reflux coils in acid/water mixture and it worked great for that too.

Just be sure to rinse the hell out of everything when you’re done. Some ‘may’ recommend using baking soda & water to neutralize any residual acid in/on the pipe, but I didn’t bother … I just rinsed the hell out of everything.

Re: CLEAN COPPER PIPE

Posted: Wed Jul 07, 2010 5:59 pm
by jackalope
NineInchNails wrote:
I would use a trash bag folded up several times and use it as a cap over one end of your pipe. Then secure it using a hose clamp so that the end of the pipe is water tight. I'd fill it approx 1/2 way with water then pour some Muriatic acid (from the hardware store) inside the pipe. Now all you have to do is top it off with more water. Leave it for a few hours and it should strip it clean.

If diluted acid doesn't work then you could try using acid straight out of the jug and pour it through (pipe set at an angle). I'd try at least a test spot first to make sure that it works. You can use a bucket on the other end of the pipe to collect the acid as you pour it. You might have to pour it through several times and rotate the pipe a bit between each pour to ensure that you get every square inch of the interior.

I've been using Muriatic acid to strip the interior of my stainless steel pipes that had a BUNCH of mineral buildup inside them and it worked like a charm. I have also been soaking my reflux coils in acid/water mixture and it worked great for that too.

Just be sure to rinse the hell out of everything when you’re done. Some ‘may’ recommend using baking soda & water to neutralize any residual acid in/on the pipe, but I didn’t bother … I just rinsed the hell out of everything.
Thanks Nine. :) Good Idea. I'll be sure to take before and afters when i give it a try.

Re: CLEAN COPPER PIPE

Posted: Wed Jul 07, 2010 6:07 pm
by LWTCS
Rubber gloves, goggles and full protection cloathing.

The muriatic acid will work like a charm.

4 to 1 might be a good place to start.

Re: CLEAN COPPER PIPE

Posted: Sat Dec 31, 2011 12:26 am
by Scotty72
NineInchNails wrote:
I would use a trash bag folded up several times and use it as a cap over one end of your pipe. Then secure it using a hose clamp so that the end of the pipe is water tight. I'd fill it approx 1/2 way with water then pour some Muriatic acid (from the hardware store) inside the pipe. Now all you have to do is top it off with more water. Leave it for a few hours and it should strip it clean.

If diluted acid doesn't work then you could try using acid straight out of the jug and pour it through (pipe set at an angle). I'd try at least a test spot first to make sure that it works. You can use a bucket on the other end of the pipe to collect the acid as you pour it. You might have to pour it through several times and rotate the pipe a bit between each pour to ensure that you get every square inch of the interior.

I've been using Muriatic acid to strip the interior of my stainless steel pipes that had a BUNCH of mineral buildup inside them and it worked like a charm. I have also been soaking my reflux coils in acid/water mixture and it worked great for that too.

Just be sure to rinse the hell out of everything when you’re done. Some ‘may’ recommend using baking soda & water to neutralize any residual acid in/on the pipe, but I didn’t bother … I just rinsed the hell out of everything.
Brilliantly simple :)

Thanks

Re: tried it..CLEAN COPPER PIPE

Posted: Wed Nov 30, 2016 6:37 pm
by slim49
Well , I took a 4 inch PVC pipe Capped it. put my inch and a half copper tube down in it . I attached a 12 volt 6 amp battery charger to it and um I put some rolled aluminum foil inside the tube and Loosely wrapped foil around it to create some galvic reaction . gave it about an hour charging off and on and then let soak overnight, probably about 20 hours total . marked deeply but I'm in the process of Polish it all off . I got it super clean. The green foam created while running 12vdc was interesting.
BTW:
I Was suprised by how well salt worked!