RE: Coil Form needed 2

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "makinglightning comcast" <makinglightning-at-comcast-dot-net> 

What makes the green sewer pipe different? I see this in the larger sizes
and it seems different than the white pvc, harder and heavier.



-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Sunday, May 16, 2004 10:58 PM
To: tesla-at-pupman-dot-com
Subject: Re: Coil Form needed 2

Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net>


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, May 15, 2004 8:36 PM
Subject: Re: Coil Form needed 2


  > Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
  >
  >
  > Experimenters should use caution when trying to use large PVC pipe as a
  > coilform.  We used PVC pipe coated with 3 coats Glyptal inside and
outside
  > for our line of VDGRF generators.  As soon as we crossed the 10 inch dia.
  > threshold the VDGRFs stopped operating properly (3 inch spark from a 40
inch
  > dia. terminal) even though the small 6 inch ID PVC pipes worked great up
to
  > 750 kV DC.

I wouldn't be surprised if the larger sizes of pipe have nonuniform plastic
in the wall.  I was turning some white PVC pipe (4"_ on a lathe and
discovered that only the outer layer was actually white, and the inside was
sort of grayish.

I don't know how they make the stuff (extrusion probably), but it's entirely
possible that they extrude a "nice clean" layer on inside and outside of the
pipe.

For what it's worth, if you look at ABS DWV (the black stuff used for
sewers), you'll see that it's actually a foam in the middle of the pipe
wall.