Re: Polyurethane (fwd)

["Tesla list" <tesla-at-xxxxxxxxxx>]

Original poster: Tesla List Moderator <mod1-at-poodle.pupman-dot-com>



---------- Forwarded message ----------
Date: Wed, 06 Dec 2000 17:15:22 -0800
From: Ed Phillips <evp-at-pacbell-dot-net>
Reply-To: ed-at-alumni.caltech.edu
To: Tesla list <tesla-at-pupman-dot-com>
Subject: Re: Polyurethane (fwd)

> I have an 8" form ( lexan) with an oil based poly on it and so far it hasnt
> begun to craze or crack ( its been almost 2 years now). If you plan to go
> ahead with your plans, take the extra time to keep the drips and overspray
> off of the portions of the tube you want to keep clear.  It will look really
> nice once its done. There is one thing I must mention tho...  temperature
> changes ( about 60 degrees worth (( 90 - 30)) will cause the poly to
> "seperate" at about 1" intervals all the way up the coil. Im figuring that
> the copper contracted faster/slower than the poly and lexan and caused the
> splitting. Altho the splitting hasnt yey caused any flashover or arcing
> problems but that is another story to see about later on.
> 
> Scot D

	Word of caution.  I just installed some Lexan window "glazing" and
notice that the protective paper warns the user to keep isopropyl
alcohol away from the stuff.  Before using any solvent-based materials
on polycarbonate I'd recommend a trial test of a scrap piece.  I've seen
both Lucite and polystyrene craze into tiny pieces when wet with the
wrong solvent.

Ed