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Thread: Where can I buy 10/2 Al wire?

  1. #31
    Retired Defense Industry Engineer jadnashua's Avatar
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    Are you familiar with a thermite reaction? Basically, powdered aluminum and powdered iron oxide (rusted iron). If you get the reaction started, the aluminum will strip the oxygen out of the rust, leave molten iron, and end up as aluminum dioxide (aluminum rust) and iron after it cools off. Aluminum in its elemental state almost always has or will have within milliseconds a rust layer on top. The reason it doesn't flake away like iron is that it is both very stable and essentially the same size as elemental aluminum thus sealing the surface as opposed to iron oxide which is bigger in volume, thus exposing more elemental iron to the ravages of the oxygen rich environment we live in.

    You've been lucky...aluminum will rust without any moisture or other accelerants all on its own. Aluminum oxide is an insulator, thus acts like a resistor, thus generates heat. That's dangerous.
    Jim DeBruycker
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    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  2. #32
    Electrical Contractor/Instructor jwelectric's Avatar
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    Quote Originally Posted by Alectrician
    I am TRYING to open up a dialog
    Okay then how about explaing the plain old chemical facts found in this link

    Being that the chemical reaction has not changed over the past few thousand years I wonder just what you base your statements on.

    Let me also say that I can sit here as type anything I want to and say it is what someone else said but instead I would rather give a link to a site that everyone can research theirself.

  3. #33
    Electrical Contractor/Instructor jwelectric's Avatar
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    Quote Originally Posted by Alectrician
    I just want to know what you did between 86 and 95 to make splices in Al wiring?
    Splicing what to what?
    I used a component that was listed for the use as was outlined in the NEC that I copied and posted.

    I can show you aluminum terminations that are bad and good, inside and outside, aluminum to aluminum, and various other installations.
    What I can’t do, nor can you, is show a connection of copper to aluminum where the copper comes in contact with aluminum that is more than a couple of years old that is a good connection.
    Up till this point the discussion has been about the splicing copper to aluminum at which you came back with some cock and bull that was supposedly from some manufacture of wire nuts that wouldn’t hold water on the best of days.

    Now that I have posted a link that explains the chemical reaction when aluminum comes in contact with copper no matter where it is located I await your reaction.
    I patiently await your explanation of how you can stop galvanic corrosion of the two metals when current is passed through them.

    Antioxidants will stop the oxidation of the aluminum but it will not stop the galvanic corrosion that is an electro-chemical reaction between the two metals.
    Please send that wire nut manufacture an email and have them explain this away.

  4. #34
    Retired Defense Industry Engineer jadnashua's Avatar
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    The point trying to be made is that while people think of aluminum as being very stable, it has a very high afinity to react with other metals and oxygen. The thing that saves it from wasting away to a lump of AlO2 is that it generates a coating that insulates the interior portion of the metal from oxygen. I tried to point out how much Al wants to corrode by the thermite example...it will literally strip the oxygen from the FeO2 molecule, and as it becomes more stable, gives off a huge amount of heat, enough to leave liquid iron as the result.

    Stick aluminum in intimate contact with other metals, and it WILL end up with corrosion. How much is determined by how far apart they are in their reactivity. Stick copper and iron together, and you've got problems. Stick copper and brass (an alloy) together and you're okay. Aluminum is quite reactive. It also expands and contracts much more than some other metals, and this action as well can make electrical connections fail - the reaction can expose more elemental aluminum to corrosion, and work screws out, when used.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  5. #35
    Retired Defense Industry Engineer jadnashua's Avatar
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    Different metals in contact with each other produce galvanic action...i.e., produce a battery effect. When that happens, one accepts electrons and the other gives them off. In the process, the metals are changed. Same thing happens in your car battery. If you select metals to touch that are very similar, you get almost no reaction, or it is so slow that you would be hard pressed to notice in your lifetime (but it does and is measurable). It just so happens that aluminum is near one end of this scale which means that most other metals will react with it. It doesn't require air, but if you can cut that out, it does slow things down some, but cannot stop it. Choose metals far apart on the scale, and you get major corrosion fairly quickly.

    There's all sorts of info on this, here's one link I googled http://www.wpbschoolhouse.btinternet....htm#aluminium
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  6. #36
    Plumber jimbo's Avatar
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    This thread has gone off the track a little, so in the interest of civility I closed the thread. If anyone wishes to continue a discussion of the corrosion or whatever in a quieter tone, please start a new thread.

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