I appreciate the respones. However, I think 2 important design concepts are:
1.Moisture resistant ptfe tubing: Sealed at both ends, after the wire is in the tube, creating an airtight environment, preculding oxidation.
2.Solid core wire versus stranded wire.
Stranding, either bare or covered in PVC or other cheap plastic coatings, have 2 proven downsides. One is oxidation of the strands, which could be overcome if they were sealed in ptfe tubes. However, the other problem is: The electrically induced vibration of the strands in a random manner.