Sonotube (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 4 Jun 2007 15:39:51 -0700
From: Jim Mora <jmora@xxxxxxxxxxx>
To: 'Tesla list' <tesla@xxxxxxxxxx>
Subject: Sonotube

Hello All,

I am going to bring up the old topic of sonotube coil forms. I have both an
8" and a 12" thin wall PVC coated coils. I want to get up into the 24KVA
league which I'm told needs to get into the 20"-24" diameter size.

I can buy Sonotube 24" with a .25" wall thickness which has a waxy coating
on the inside. Cost is only ~$8.00 a foot. The cheapest PVC I have found is
for ducting but runs >$30/ft for 20". Fiberglass, while ideal, is much more,
and way more heavy to transport (of course > mile of #12 or #10 awg will be
where the weight is)!

So the question is how to coat the tube and how to baffle it. I am thinking
of bringing the coil form out near Las Vegas and let it set a couple of days
in the dry desert heat, than coating the OUTSIDE with marine grade epoxy.

I am thinking three .5"X 24" equi-distant polyethene or coated plywood disks
would be screwed in place with countersunk flat head nylon screws with epoxy
applied to the area on the exterior. An interior adhesive would be
desirable. The tube length would be 10 feet.

If anyone has experience making the interior adhere to anything, I would
like to know about it. Perhaps a completely evaporative volatile solvent
such as acetone could clean the inside... Or is the Sonotube not the way to
go? 

Thinking down the road...

Thanks
Jim Mora