Really high voltage potting (Potting on the Cheap) (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Sun, 07 Sep 2003 22:15:28 -0300
From: Antonio Carlos M. de Queiroz <acmq@xxxxxxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Really high voltage potting (Potting on the Cheap)

Hi:

I am searching for a good method of gluing a stack of two or three
acrylic disks, to make an electrostatic machine with embedded sectors
in the disks. Imagine a Wimshurst machine with the sectors inside the
disks, accessed only through small buttons.
I tried so far two methods:
Gluing the disks with Araldite results in uncertain performance.
Leakage is significant and water absorption is a big problem.
Gluing the disks with hot glue works very well, but requires an
oven, and the acrylic disks get a bit deformed by the procedure.
I can mention that wax works too, but is weaker and can crack.
I have two machines that ate now built with the hot glue method:
http://www.coe.ufrj.br/~acmq/wommelsd.html
http://www.coe.ufrj.br/~acmq/wehrsen.html
I am now working in a larger machine, with disks that are too large to
fit in my oven, and that anyway would probably deform excessively
(I could adjust the border of the composite disk after assembling it,
and find a way of mounting the contact buttons after the assembly too.)
So, I am looking for an adequate glue that dries without contact with
air, and becomes an insulator as good as acrylic. Some suggestion?

Antonio Carlos M. de Queiroz