Sciencemadness Discussion Board

getting rid of pvc from copper wire

Random - 10-12-2014 at 12:13

I have a bunch of copper wire and I don't think burning it is an option and using a knife to deal with the insulation part is pretty hard. Is there a way to chemicaly destroy pvc on it or to make it easy to take it off? I think it's really resistant material so nothing comes to my mind currently.

DraconicAcid - 10-12-2014 at 12:34

A set of wire strippers is probably far better than a knife.

Anecdote: Every year, my students do a lab that involves a short piece of copper wire. They are provided combination wire cutters/strippers to cut a short piece off of the spool. Every year, most of the students try to cut the wire with the stripper part, and can't figure out why it doesn't work....

Praxichys - 10-12-2014 at 12:59

Drill a hole of the diameter of the wire and jacket through a thick block of wood. Cut the block in half through the center of the hole. Clamp the blocks together so that the hole is preserved, but clamp a pair of razor blades between the blocks so that a corner of each blade sticks into the hole about the thickness of the jacket on the wire. Tape helps in this step. The thickness of the blades and tape will compensate for the kerf of the saw cut.

When properly set-up, simply pulling the wire though the hole will cut the jacket right off into two halves. A friend of mine is big into scrapping and uses this technique.

A little more advanced version involves threaded rod and wingnuts to adjust hole size and blade depth.

Sort of like this: http://i.ytimg.com/vi/rsSjgVqHGgo/maxresdefault.jpg

subsecret - 10-12-2014 at 13:31

Set up two spools, like a clothesline that can move the wire along. In the middle, build a nice, hot fire. Slowly feed the wire just over the coals.

Random - 10-12-2014 at 14:47

Wire stripper is not an option since I broke one just by trying to use it. Praxychis has an interesting method which I will probably try it the next few days. I'll cut the block using circular saw and it will be somewhat hard to preserve the hole since the saw is thick in comparison to it. If I get success I'll report back. Oh yea and if someone has few more ideas I'll be glad to hear them

[Edited on 10-12-2014 by Random]

aga - 10-12-2014 at 14:57

Stick the whole thing in a steel barrel (oil drum) set a fire under the barrel.

Catch all the HCl in a bottle of water using a pipe.

When you're done, shake the barrel.

You get Hydrochloric acid, Carbon and Clean Copper.

Alternatively just burn it.
You get seriously bad Dioxins and dirty Copper.

WGTR - 10-12-2014 at 15:30

Quote: Originally posted by Random  
I have a bunch of copper wire and I don't think burning it is an option and using a knife to deal with the insulation part is pretty hard. Is there a way to chemicaly destroy pvc on it or to make it easy to take it off? I think it's really resistant material so nothing comes to my mind currently.


https://web.anl.gov/PCS/acsfuel/preprint%20archive/Files/42_...

Stripping it with molten NaOH might be an interesting experiment. The reaction could be violent, though. I use it to strip that infernal polythermaleze insulated wire, and it works wonders. It fluxes the wire, leaving bright copper behind.

Bert - 10-12-2014 at 15:56

We generate someplace close to 1,000 lb. of scrap Copper wire per year over the last couple of years, mostly from electric matches and long runs of wire used to fire "fronts" of fireworks. Some circuits can consume over 500 feet for a single shot- Occasionaly, I will re-use such a run, but mostly it gets scrapped.

First: Most honest scrap dealers will pay you enough for insulated Copper that the effort to strip it is not worthwhile. I NEVER strip wire before recycling anymore

Second: Burning off insulation will make the wire worth less, not more in my experience. Trust me, I have tried it.

Third: Large scrap operations have innovative techniques to deal with insulated Copper- Like cryogenic freezing with CO2 or liquid N2 and tossing the bales of wire into a hammer mill! The cold embrittled plastic insulation is reduced to dust, the bare wire comes out either something like balls of Copper wool or as short pieces that can easily be separated by compressed air from the relatively light plastic dust. . From there, smelting the fairly clean wire is a lot less smoky and nasty.

Find out what the still insulated wire is worth before investing your time in any stripping technique, ideally show a buyer actual samples of your material. Call several recyclers to check prices, and KNOW HOW MUCH IT WEIGHS BEFORE YOU GO. Scrap yard operators are not all terribly honest...

DraconicAcid - 10-12-2014 at 16:02

Bert- I'm assuming the OP wants to use to copper for chemistry experiments....

diddi - 10-12-2014 at 16:37

wire burning is illegal in .au these days and subject to significant fines. the scrappies used to do it all the time back in the day.

this tool may be useful if you can justify the cost:
http://www.ebay.com/itm/52-Holes-Tungsten-Carbide-Wire-Drawp...

Amos - 10-12-2014 at 20:05

I usually just take an exacto knife and carefully cut a circle around the wire, only cutting through the plastic. I can then just slide the covering off the wire(it takes some effort), and then remove more of the plastic the same way, or grab the exposed copper wire and proceed to pull it out of the insulation.

macckone - 10-12-2014 at 20:13

Acetone, Methyl Ethyl Ketone and other organic solvents will dissolve the
PVC given heat and time. On a large scale this is an older method for
removing the coating before recycling the metal and as a bonus gives
pvc that can be reused as glue.

The newer method is the freeze and hammer method described by Bert.
If it is a small amount then dry ice may be satisfactory otherwise you
should probably go with the liquid stripper method. Be sure to dispose of
the solvent responsibly.

Random - 12-12-2014 at 14:44

Yeah guys I am actually scrapping copper and solvent method seems interesting. I wonder if it takes a lot of time. What about the glue that remains how could it be used?

chemrox - 12-12-2014 at 18:10

wire strippers or solvent. why screw around with DIY wire strippers unless you're an equipment diddler...btw dissolved PVC is shitty glue.

Random - 13-12-2014 at 17:56

I would probably already buy a wire stripper if I didn't have problems ordering from ebay (don't have paypal account and other necessary things). That's the only reason why I am messing around with other different options and diy solutions. Too bad dissolved pvc is not a good glue, but still it could be effective. I just wonder what's the solubility of pvc in acetone and how many washes would be needed. Liter of acetone is here like 5$, in comparison to scrap copper I would get 6-7$ max

[Edited on 14-12-2014 by Random]

forgottenpassword - 14-12-2014 at 01:34

DCM vapour dissolved my PVC tubing in no time at all. Just think what the liquid could do!

[Edited on 14-12-2014 by forgottenpassword]

jock88 - 15-12-2014 at 13:29

obtain a high current power supply (a welder would be great) and pass some amps through the wire for a few ten's of seconds (or whatever it takes) untill the copper is hot and starting to melt the pvc. At this stage you can pull the pvc off easily

j_sum1 - 15-12-2014 at 14:18

A lot depends on exactly how clean you need the copper. I would go for a purely mechanical solution myself. Much better separation and nothing ti ckean up.
Dissolving; burning, melting... yuck!

Dr.Bob - 17-12-2014 at 08:00

I agree with Bert, if you have any quantity of wire, stripping it is nuts. I recycle about 100 pounds a year and they pay enough for the insulated wire, that removing the insulation really loses money for a lot of work. The recyclers have ways of doing it in bulk that are likely easier and hopefully safer and cleaner than burning or dissolving it. I used to try to remove PVC with solvent, and the value of the solvent is more than the wire is worth, and you end up with a mess. The only tire spripping wire is worth it is for larger gauge wire like 12, 10, 8, 6, 4, 2, 0 and bigger diameters, where the copper weighs enough to be worth the extra amount of work, and some of those are easy to strip, with the tricks mentioned.

Random - 15-1-2015 at 14:36

Hey guys thanks everyone for help I have developed one easy method. I take huge glass 3L or so cucumber jar and put there like 400mL acetone. Squeeze the wires into the jar tight, close n shake. 24 hours later pvc becomes so soft you can slip it off with fingers on smaller pieces and on bigger easily scrape with knife. Went thru 7kg of the stuff in few days. Acetone can be reused.

400mL is like 1.5$ and there is much more worth of copper. 1.5$ would be like 300g copper.


[Edited on 15-1-2015 by Random]