form for secondary

["marzie" <marzie-at-hotpop-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

i am in the midst of building my 1st coil  and i have been reasearching tc's on
the web and by numerous web sites i have been advised not to build my secondary
on grey or black pvc pipe.....is they a reason for this??  
 
from marzie