Re: Lexan (polycarbonate)

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

Original poster: "Scott Hanson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <huil888-at-surfside-dot-net>

Greg -

Lexan will work as well as acrylic. How are you going to attach it? If by
adhesive, make sure that the adhesive "bonds" to both the end cap and the
secondary material.

I use multiple sealed baffles within my secondaries to prevent internal
arcing. If you end up with multiple baffles and therefore multiple "sealed
chambers", its probably a good idea NOT to use any solvent-based adhesive
for fear of trapping flammable (explosive!) vapors within.

If this is a big coil (8" or larger), give careful consideration to good
mechanical design for supporting the weight of the topload. If you end up
with a $300 spun aluminum toroid on top, you don't want it to fall off if a
glue bond fails. I'd suggest bonding enough sheets  of Lexan to get 1/2" to
3/4" total thickness, and drilling and tapping radially so you can use 10-15
nylon screws to secure the end plate into the secondary.

As for a rotary disc, forget it. Check the heat deflection temperature and
you'll find it low enough to cause concern. I recommend only linen phenolic
laminate, or any of the fiberglass reinforced G-series epoxy laminates.

Regards,
Scott  ----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, July 01, 2002 11:36 AM
Subject: Lexan (polycarbonate)


> Original poster: "Mr Gregory Peters by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
>
> Hello all,
>
> I went to get some acrylic sheet from the plastic shop to cap my
> secondary. The cutters had gone home for the day, so I would have had to
> buy a whole sheet. They guy instead gave me a 6mm lexan (polycarbonate)
> scrap sheet for next to nothing. I thought this was a great deal, as
> lexan is apparently easier to work with and alot tougher, and I have
> enough to make another RSG rotor if I want. However I have read
> somewhere that lexan is prone to catching fire relatively easily. Is
> this true? Can anyone see a reason NOT to use it to cap my secondary?
>
> Cheers,
>
> Greg Peters
> Department of Earth Sciences,
> University of Queensland, Australia
> Phone: 0402 841 677
> http://www.geocities-dot-com/gregjpeters
>
>