[Lf] Another Litz wire stripping method]

[Andre' Kesteloot]

James Moritz wrote:

> Dear LF Group,
>         I recently salvaged some thick litz wire, and have been trying to
> find a workable method of stripping the insulation. The enamel is of
> the older, dark coloured type, which cannot be removed by dipping
> in molten solder. The overall conductor thickness is about 4mm
> with 729 strands, and a spirit burner as previously suggested on
> this reflector just does not make any impression. A blowtorch does,
> but also burns away the outer strands and the plastic sheathing. I
> believe chemical strippers are available, but have to be melted at
> high temperature, and then neutralised afterwards.
>
> However, the following seems to work quite well - strip about 50mm
> of the plastic sheathing, and wrap the end 25mm of wire strands
> tightly in a piece of copper foil (such as can be peeled off some
> PCB laminate, or the type used for EMC shielding). Wrap a smaller
> piece of foil around the 12mm of wire strands nearest the stripped
> back sheathing, and grip with a pair of pliers - this acts as a
> heatsink to protect the sheathing. Heat the foil covered end red hot
> with a blowtorch. The enamel burns off with a small flame at the
> end of the foil, while the foil protects the copper strands from the
> blowtorch flame. When the flame goes out, leave to cool and
> unwrap the foil. The wire strands are coated in black, shiny
> residue, which can be cleaned off by rubbing the end of the wire
> against the bottom of a shallow dish full of water, as if cleaning a
> paint brush. Somewhat suprisingly, this leaves clean, shiny strands
> of copper that can be soldered in the usual way.
>
> Just thought this might be useful to know,
> Cheers, Jim Moritz
> 73 de M0BMU