Oil and Acrylic Plastics

From:  Thomas McGahee [SMTP:tom_mcgahee-at-sigmais-dot-com]
Sent:  Friday, June 12, 1998 7:16 AM
To:  Tesla List
Subject:  Oil and Acrylic Plastics

I have never noticed ANY degradation of plexiglass or any other
form of acrylic with transformer oil. 

The cracking of the
plexiglass is most likely due to pressure, not oil attack.

Has any coiler out there EVER noticed degradation of acrylic
based plastics due to transformer oil? If so, please
share that with the rest of us. For my part, I can say that
I have NEVER had problems with oil degrading acrylic plastics.

Hope this helps.
Fr. Tom McGahee

> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-pupman-dot-com>
> Subject: cap  problems
> Date: Thursday, June 11, 1998 11:44 PM
> ----------
> From:  Hollmike-at-aol-dot-com [SMTP:Hollmike-at-aol-dot-com]
> Sent:  Thursday, June 11, 1998 6:24 AM
> To:  tesla-at-pupman-dot-com
> Subject:  Re: cap  problems
> Bob,
>    I haven't looked at material compatability charts as of yet, but it sounds
> like the oil attacked the acrylic and the tape.  It also sounds like the poly
> absorbed the oil and swelled, causing the acrylic to shatter, once weakened
> the oil.  It sounds like your cap will survive once you replace the acrylic
> with something more compatible.  
>      You should also measure the capacitance again.  The swelling of the poly
> surely has changed the capacitance and you may have to add a plate or two to
> get back to your design capacitance.
>    You should try to contact the manufacturer of this oil and see if they can
> provide you with a commpatibility chart for it.  It sounds as though a thick
> sheet of polypropylene might be ok for sandwiching the cap, but it may soften
> and swell like the dielectric.  How about glass plates for sandwiching the
> works?  It would be more easily breakable, but would not be attacked by the
> oil.  
>   Good Luck.
> Mike Hollingsworth