Gary Coffman said:
Each strand of Litz wire is separately insulated (that's what makes it
Litz wire). You have to strip that insulation off before it will take solder.
There are chemical dips you can use to do this with some insulation
formulations. Consult the wire manufacturer for the recommended
Since I didn't have a clue as to what Litz wire was, here's more than you
ever wanted to know about Litz wire:
The term litz wire is derived from the German word litzendraht meaning
woven wire. Generally defined, it is a wire constructed of individual film
insulated wires bunched or braided together in a uniform pattern of twists
and length of lay.
The multistrand configuration minimizes the power losses otherwise
encountered in a solid conductor due to the "skin effect", or the tendency
of radio frequency current to be concentrated at the surface of the
In order to counteract this effect, it is necessary to increase the amount
of surface area without appreciably increasing the size of the conductor. It
is also essential to position each individual strand in the litz
construction in a uniform pattern moving from the center to the outside and
back in a given length.
Even properly constructed litz wires will exhibit some skin effect due to
the limitations of stranding. Wires intended for higher frequency ranges
require more strands of a finer gauge size than litz wires of equal cross
sectional area but composed of fewer and larger strands.
Polyurethane is the film most often used for insulating individual strands
because of its low electrical losses and its solderability. Other
insulations can also be used. Litz wires are generally further insulated
with a single or double wrap or serving, of a textile-typically nylon-but
are also available unserved.