I have ground wire coming out of the house
2 or
#4 stranded. Had to disconnect due to external waterproofing. Installing 2ea 5/8″ rods. Problem: old wire is covered w/ paint partway & dirt rest. what is the best way to clean this stranded. I have used 409, wire brush, and sandpaper. concerned about getting good electrical connection. Suggestions? Radio Shack doesnt sell flux anymore. Only flux I have is plumbers flux, anc am concerned about acid in that.
Thanks
Replies
Gently separate the strands and gently scrape each one.
replace it?
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Wow, 409 didn't work?
Burn the paint off with a torch, and then go at it with a wire wheel you mount in a drill.
409 did cut some of the surface dirt, but still have a good bit down deep.
As for replacing, it runs in behind vinyl siding, really do not want to mess w/ that if I dont have to.
go with previous suggestion:
Burn the paint off with a torch, and then go at it with a wire wheel you mount in a drill.
Had to strip some polyarkelene (SP?) Imideze insulation off Litz magnet wire, oxy act. flame with surlpus O2 for just the time to see it flame yellow and the wire brush at >5000 RPM and light touch is very effective, should work with simple propane torch for just paint on the wire.
JH - I am constantly amazed at the things you do. If I ever get staranded on a remote island, I want you there. Well, you and a Home Depot and a couple of girls I used to date ...
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
Won't that heat restructure the copper??? As in brittle....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
au contraire!
If you have a piece of work hardened wire, (or copper plate or sheet) the best way to get 'flexibility' (aka non-brittle) back is to take the hardness out thru heat. Do have to observe that you don't oxidize the copper too much, quick water quench usually removes the oxide.
Have taken work hardening out of magnet wire (for transformers, etc) by putting a 20X or so rated current thru a wire for 10 seconds (example, 30 A thru 22 AWG), that will anneal the wire without causing insulation damage (150C transformer wire, probably would damage TW pvc insulation, never tested TW)
Pardon the near duplicate post, BT is so slow this AM I thought I forgot to hit post the first time.
Heat removes the work hardening temper, makes copper less brittle, more workable.
Simple way to take work hardness out of copper wire is to put a 20X rated current thru it for 10 seconds. Caution, this probably will damage TW type wire, the 20X for 10 sec is based on testing of 150C rated wire for overcurrent and duration for no insulation damage.
Edited 9/7/2004 8:48 am ET by JUNKHOUND
Dip it in muriatic acid for a bit, then in water to neutralize. Clean with electrical contact cleaner spray to displace the water. Solder the terminal connector on with a torch. You're good to go with that if the solder sticks well.
If not...do like they say on the shampoo bottle: Lather, Rinse, Repeat....
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
In my area, soldering a grounding conductor is a no no. The theory being that if there is a enough amps going to ground in a short, enough heat may be generated to melt the solder and decrease the conductivity. If you want to be code compliant, you might want to check with a local electrician or your local electrical inspector if you are planning on doing any soldering on that conductor.
I'll grant that 'enough amps' could theoretically heat up the wire enough to soften the solder, but I don't see liquified metal decreasing conductivity enough to make any practical difference in this type of situation. Yes, super-cooled conductors have lower resistance...but with the kind of amperage you'd need to cause a 2-0 copper ground wire to melt solder--we're talking lightning strikes here, not stray house current--I don't think a few u-ohms more or less are gonna be all that noticeable once the smoke clears and your ears stop ringing....
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
I don't see liquified metal decreasing conductivity enough
Just for your future reference, what actually happens is that as the solder reaches the pasty temperature range and loses strength, it is so weak the magnetic forces on the wire pull it apart. Not conjecture, have done this in testing at 150 kA on 2/0.
BTW, 4 million amps does not fuse 250 MCM, it BREAKS it open. 4/0 copper at 300 kA also breaks before fusing.
2nd BTW, typical air to ground lightning is less than 20,000 amps, so just bolt it (see you did in later post) .
Man the stuff you know is truly awesome. Y'oughta change your nickname to Mr. Wizard or something, LOL....
But this raises another question--no solder I have ever worked with has any ferrous material in it, so why would it be affected by magnetic forces? Another question #2: How would a length of copper that is not wrapped around a ferrous (soft iron) core generate magnetic field anyway?
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
a pair of wires with current going in the same direction attract in air (or vacuum) due to their self generated magnetic field (no iron needed), wires in a loop try to push the loop to a bigger diameter, a single wire tries to staighten itself out. Forces are proportional to current squared, so at 20 A or so the forces are negligible, but a million times higher at lightning currents.
Dang! I'm gonna have to have a few words with my old high school General Science teacher fer not teachin' us that.
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On second thought, no; I just remembered he was a pretty mean dude....
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On third thought, why not? The old buzzard must be 80 years old by now Hee hee hee....
View ImageDinosaur
'Y-a-tu de la justice dans ce maudit monde?
Thanks Dez,
But I am more concerned about the dirt.
In similar situations I have used a knife to carve off any bulk paint or putty buildup. I once used a torch to soften some tough white roofing liquid membrane and caked paint. Once the bulk material is off I had luck using a stainless steel wire brush and, if it is known and seem appropriate, a solvent that will dissolve the material. Paint thinner works on a lot of oil paints, roof tar and some caulks.
Once it is mostly clean with mostly just oxides remaining I switch to a small stainless steel brush. My favorites look like largish toothbrushes. This I use perpendicular to the strands to get the outside and then parallel to get between the strands.
I have found that scraping, sandpaper in various forms and wiping doesn't get between the strands like I like. In critical cases I will spread the strands slightly to allow the brush to get deeper but for standard ground conductors I think this is overkill.
Fact being that ground rods, even extensive grounding arrays, really don't make all that good a connection to the earth and the earth in most locations is not that good a conductor itself. Grounds are great for sinking massive surges you see with lightning. Surges that want to go to ground anyway. But they are marginal return paths, even a backup one for a lost neutral.
Once clean you can use this brush, once cleaned, to apply and work in some anti-oxidant compound to help keep the crud at bay. Some might pot the connection with epoxy. Others use a spray on clear coating. My preference is an thick coat of antioxidant or, in a pinch, grease because these can be easily cleaned, inspected, tightened and , if need be, repaired.
Remember that aluminum oxide is an insulator so any connection has to be cleaned while covered with anti-oxidant to keep oxides at bay. Copper, on the other hand, had oxides that conduct fairly well so you need not clean the connection dead bright. A little dullness is OK.
There are chemical cleaners but most have to be carefully rinsed away or they attack the copper in time. Even organic fluxes, I did a test involving pennies and plumbers non-acid flux, can accelerate corrosion.
Solder, in and of itself, is not an issue. It is allowed. But it is not allowed to be depended on for either mechanical of electrical connection. In other words once you make up the connection with standard mechanical connectors your free to solder them if you wish.
Typically this is entirely a waste of time and effort. Get a couple of split bolts, overlap the conductors and use two split bolts on them. Tighten firmly. This connection you can coat with grease or anti-oxidant compound and tape to prevent corrosion. End of problem.
thanks, I cleaned w/ "toothbrush" & sandpaper, got fairly clean. clamped w/ ground rod clamp, and antioxidant all over.
Sounds like it worked out. Good to hear it when things work.
I haved had need to get into this, but I was under the impression that you could not use a split bolt on a grounding electrode wrie (or anyother connector).
That if you need to splice that you can only use a non-reversable connection. Exothermic is one type and maybe some types of compression fittings.
As I understand it you are correct but in this case the guy has a broken conductor and no intention of replacing the entire length. Given that limitation copper split bolts doubled over overlapped conductors, barring cadwelding, would be the preferred method.
No it isn't code but given the likely conductivity of the two ground rods with the earth, usually pretty poor and another reason #6 is, in effect, the largest GEC that can be demanded, I think it is about as good as it is going to get.
The GEC is, typically, a very poor backup to a damaged neutral and is only really effective as a sink for massive surges, like a lightning strike.