Re: Plastics question

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Antonio Carlos M. de Queiroz" <acmdq@xxxxxxxxxx>

Tesla list wrote:

> Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>
> We have used both black delrin and black (smoked color) acrylic with 
> no HV leakage or tracking.
> When you tap the acrylic for the fasteners be sure to use kerosine 
> if in a lathe.  Also gently (very gently) anneal the acyrlic after 
> tapping in your oven to prevent the sharp tap edge points from 
> expanding into cracks that will radiate to the edge of the acrylic 
> and cause fastener failure.

I have never seen this happen. Drilling and tapping acrylic really needs
some lubricant, or the acrylic melts or cracks too easily. Annealing
acrylic is a temerity, as it shrinks and deforms with heat. The heat
developed by tapping (with lubrication) is probably enough.

Antonio Carlos M. de Queiroz