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Winding Varnish ???

Discussion in 'Electronic Repair' started by rijo, Jan 13, 2006.

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  1. rijo

    rijo Guest

    Hi group , I need to know what type of varnish is used on electrical
    windings . I have several projects that will require varnish coated
    copper wire . Thanks for any good answers to my question in advance . Rick
  2. n cook

    n cook Guest

    Other than it should be traditional resinous copal varnish, not
    polyurathane, as far as i know.
  3. Rick


    I usually use GC Electronics Red Insulating Varnish (p/n 10-9002).
  4. Set Square

    Set Square Guest

    In an earlier contribution to this discussion,
    I'm sure I've heard of Shellac being used for this purpose.
  5. Smitty Two

    Smitty Two Guest

    If you're winding your own coils, start with wire that's already coated.
    I've wound guitar pickups, power and output transformers for tube
    amplifiers, and coils for magnetic bearings. I usually buy wire from
    MWS, although I imagine there are other suppliers, too.

    You have a choice of several different insulating coatings. Some will
    melt with the heat of a soldering iron, which makes termination easy,
    and others require mechanical stripping.

    Beyond the insulating varnish, you can also buy wire with an additional
    coating that melts in an oven, fusing the coils together and making the
    coil rigid without a core or bobbin. There are also coatings that melt
    with solvent, and pulling the wire through a damp sponge of solvent
    bonds the coils together.

    To keep the coils quiet, if they aren't bonded by heat or solvent, you
    can vacuum pot them in melted paraffin, or some commercial potting
  6. mc

    mc Guest

    If you're supposed to use enameled wire (wire with an enamel coating for
    insulation), use wire that comes that way from the factory ("magnet wire").
    If you want to put a heavy plastic coating over a finished coil, I've had
    good luck with (don't laugh) PVC pipe cement, which is a thin clear plastic
  7. cnctut

    cnctut Guest


    A-C Motor Repair and Rewinding published in 1941 says this--"...dip
    the coil in a good black baking varnish and bake it dry...The varnish
    should be kept at a specific gravity of about .84; the coils are dipped
    cold and allowed to soak about 15 to 20 minutes until the air bubbles
    stop rising to the surface of the varnish. Then the coils are drained
    and baked from 6 to 10 hours in an oven with forced ventilation, at
    from 115-120 C or about 240 to 250 F. For normal operating conditions
    two dips and baking are preferable...four or five dips and bakes are
    advisable for bad operating conditions....."

    I have never insulated my own wire but it can be done--enamel wire just
    sounds simpler.

    Good luck,

  8. rijo

    rijo Guest

    Thanks to everyone who participated answering my question . Thanks
    again , Rick
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