CLR: amazing copper wire cleaner

[General Geoff]

On the back of a bottle of CLR, it specifically states NOT to use it on copper. However, I just successfully used it to very quickly and easily strip some heavy gauge stranded wire used for a truck battery terminal (broke the original terminal when trying to take it off the batt post, it was just too brittle in ~5 degree weather!). Unscrewed what was left of the old terminal, and just dipped the frayed wire end into a small glass of CLR for a minute. Watched as the copper went from nasty green/black corrosion, to shiny and clean. Took it out, dipped in a glass of water to get any residual acid off, then slathered in dielectric grease before clamping a new terminal end on. Very strong electrical connection.

Thought I'd pass along the tip to anyone who needs to replace a terminal but doesn't have the slack to cut off the ratty ends of the wire.

 

[1982fxr]

wonder why they say not to?

 

[The Cobbler]

from the clr site
What will CLR do to copper or aluminum?
CLR will take the finish off of aluminum and copper.

 

[kabinenroller]

I have not tried CLR but I use Lime X ( same as Lime Away) to strip zinc plating from nuts and bolts. I Parkerize a lot of hardware for restoration projects and the metal must be bare. Soak it in Lime X then blast it with media and it takes the Parkerizing proccess perfectly.

 

[Ed ke6bnl]

this is good info. I made the mistake of taking the parts I was making and dipping in pool acid and then came in the garage to solder, big mistake every piece of bare metal is now rusty. including my buggy frame.

 

[djjsr]

Good tip for cleaning the cable. But why do you clean off all of the crud and corrosion to get a good connection then apply an insulating grease before attaching the terminal?

 

[pauls_workshop]

The reason they say not for copper is for indoor plumbing fixtures, faucets and such. i used this in the past on zinc plated copper or other finished copper faucets and it destroyed the finish completely. Faucets are trash and need to be replaced. So for uses like battery wire cables, great, but not for any indoor or outdoor copper use if it has any finish at all over it. Trust me. - Paul

 

[pauls_workshop]

Good tip for cleaning the cable. But why do you clean off all of the crud and corrosion to get a good connection then apply an insulating grease before attaching the terminal?

That is to protect the integrity of the electrical connection later. You want the outside of the wires and the inside of the clamps to it to stay good for a long long time and not degrade the electrical connection easily later. - Paul

 

[djjsr]

That is to protect the integrity of the electrical connection later. You want the outside of the wires and the inside of the clamps to it to stay good for a long long time and not degrade the electrical connection easily later. - Paul

Doesn't an insulating material degrade the connection? I understand using the grease on the outside after the connection is made to protect it, or give it a shot of that terminal spray.

 

[pauls_workshop]

Not if it is a dielectric grease, which was specified here. If it conducts electricity perfectly well, it does not in any way hinder the electrical connection integrity, it merely adds a large amount of future protection against later corrosion and degradation of the joint. If you DON'T do this, the joint can become bad again oh in 5 years or so and have to repeat the above process, as battery white nastiness will embed itself inside the connection and go up the wires like snow cancer over time. - Paul

 

[toplessHO]

dont do it,it will keep degrading the surface and will start to corrode
use no ox if you want to slow down the corrosion. Cheaper is to use Pepsi or coca cola
but neutralize with baking soda.

 

[theoldwizard1]

Eric the Car Guy used CLR to un-clog a heater core. Left the hoses connected to the core and tied them up. Filled it with CLR and let it sit for about an hour. Blew it out with a garden hose. Success !!

 

[Zeke]

this is good info. I made the mistake of taking the parts I was making and dipping in pool acid and then came in the garage to solder, big mistake every piece of bare metal is now rusty. including my buggy frame.

Any acid will do that. Phosphoric and down the line. What the dipping places use to get the parts to the customer rust free is to treat them with a phosphate compound post dipping. This is after neutralization.

 

[ez-duzit]

The CLR (and the water rinse) will just wick up the inside of the cable.

 

[General Geoff]

Doesn't an insulating material degrade the connection? I understand using the grease on the outside after the connection is made to protect it, or give it a shot of that terminal spray.

Dielectric grease itself does not conduct electricity very well, however because it is a relatively light, mobile grease, any physical connection between hard materials such as metal simply displaces the grease and provides good electrical contact. The grease then surrounds the connection and inhibits water and air from getting to it and oxidizing the metal.

Dielectric (insulating) grease is recommended for electrical connectors because it won't conduct current between very close contacts, so it's safe to use on wiring harnesses. Theoretically, on a simple battery terminal where it's just one big lead, you could use pretty much any water repellent grease, conducting or nonconducting.

 

[ttpete]

The CLR (and the water rinse) will just wick up the inside of the cable.

This. Eventually, the cable will corrode inside the insulation where it can't be seen. Never use acid to flux electrical connections.

 

[General Geoff]

This. Eventually, the cable will corrode inside the insulation where it can't be seen. Never use acid to flux electrical connections.

CLR is a relatively weak, hygroscopic and biodegrading acid. I cannot imagine how it could wick up and corrode a thick copper cable after being neutralized and then displaced by silicone grease.

That said, if it does happen, I will be more than happy to replace the cable with new.

 

[kctyphoon]

I've used CLR to clean all the soot off the inside glass of my wood fireplace. Works great.

 

[firworks]

I would suspect they are saying not to use it on copper plated surfaces. If you used it to clean the bottom of a copper bottom pan it'd get to the base metal. If you use it on a copper wire that is copper through all you can do is dissolve an outer layer. If you properly rinse it off I think you'll be fine once you've taken off the nasty stuff on the outside.

It's a cleaning product. What would be the most likely copper surface you'd run into when cleaning? Copper plate. You wouldn't run into a copper ingot while cleaning your home.

 

[Yv.]

Eric the Car Guy used CLR to un-clog a heater core. Left the hoses connected to the core and tied them up. Filled it with CLR and let it sit for about an hour. Blew it out with a garden hose. Success !!

I'll have to try that some time.

 

[General Geoff]

You wouldn't run into a copper ingot while cleaning your home.

Maybe not your home!

 

[ttpete]

I would suspect they are saying not to use it on copper plated surfaces. If you used it to clean the bottom of a copper bottom pan it'd get to the base metal. If you use it on a copper wire that is copper through all you can do is dissolve an outer layer. If you properly rinse it off I think you'll be fine once you've taken off the nasty stuff on the outside.

It's a cleaning product. What would be the most likely copper surface you'd run into when cleaning? Copper plate. You wouldn't run into a copper ingot while cleaning your home.

Fluxes are also cleaning products. They clean the metal so solder can coat the metal, and in the end, most cause corrosion. A stranded cable that's green with corrosion should either be cut back to clean metal or replaced because there's no way to clean it and not leave chemicals in it that will cause corrosion over time. The problem is that capillary action will **** the cleaning agent up under the insulation farther than one would think.

I've only found one soldering paste flux that is acceptable for electrical work, and that goes by the brand name Nokorode. Because it's not acid, it doesn't clean as well as the other fluxes and requires that the metal be fairly clean to begin. The only type of solder I'll use for electrical/electronics work is rosin core.

 

[ez-duzit]

tt--good post. But battery cables should be properly crimped, not soldered.

 

[ttpete]

tt--good post. But battery cables should be properly crimped, not soldered.

That, too. I just wanted to address the flux/cleaner issue.

 

[General Geoff]

A stranded cable that's green with corrosion should either be cut back to clean metal or replaced because there's no way to clean it and not leave chemicals in it that will cause corrosion over time.

What about a baking soda solution, which would neutralize acid even more effectively than water?

 

[ez-duzit]

Why apply anything that will wick right up the cable?

Replace it.

 

[theoldwizard1]

Dielectric grease itself does not conduct electricity very well, ...

Dielectric grease does NOT conduct electricity at all. One application that most people don't think about is reducing interference in "spark gap" applications (distributor rotor tip to cap).

... however because it is a relatively light, mobile grease, any physical connection between hard materials such as metal simply displaces the grease and provides good electrical contact. The grease then surrounds the connection and inhibits water and air from getting to it and oxidizing the metal.

EXCELLENT explanation ! There is still metal to metal contact but it is now "sealed" inside the grease.

Dielectric grease is still the best backup to "weatherproof" connectors.