Transformer Iron cores depend on Iron with a Oxide surface (black). I
don't know if your
MIG wire is suitable for that treatment.

Bill K7NOM

Winston wrote:
Hi all,

I want to build up a magnetic core using a few hundred feet of 0.023"
diameter ER70-S6 MIG filler wire. To limit eddy current, I need to make
the wire non-conductive to low voltage (ca. 5.0V AC @ 60Hz) up to 100
degrees F (38 C).

Right now, I'm contemplating a monstrosity full of pulleys and motors,
to apply several coats of polyurethane liquid with intervening drying
stages.

I am aware of McMaster 8867K25 which is a 0.062" diameter vinyl insulated
mild steel wire. At only 249 feet per roll, I am concerned about the
need for splices, though.

How would you approach this particular challenge?

Thanks!

--Winston