Re: Concerns about Silicone

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Scott Hanson" <huil888@xxxxxxxxxxxx>

Kurt -

All of the hardware-store grades of RTV silicone sealant utilize a 
cure chemestry that releases acetic acid as the material cures after 
exposure to moisture in the air. The RTV compounds using the acetic 
acid cure system have a distinct vinegar smell.. General Electric has 
several different types of "electronic grade" RTV that release an 
alcohol during curing instead of acetic acid (RTV 133, RTV 160, 
RTV162, RTV167). The electronic grade materials are harder to find 
and quite a bit more expensive than the hardware store grades, but 
are completely non-corrosive.

I have always used the electronic grade material for sealing baffles 
in Tesla coil secondaries, but I don't know how much risk of 
insulation breakdown there is with the acetic-acid cure materials. I 
have hermetically sealed several different containers using the 
acetic acid cure RVT, and when opened months later the odor of acetic 
acid inside was overpowering.

Regards,
Scott Hanson
----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, March 14, 2006 8:54 AM
Subject: Concerns about Silicone


> Original poster: "C. Sibley" <a37chevy@xxxxxxxxx>
>
> I'm thinking about using a couple of dabs of silicone
> to affix the end caps of my secondary, but am
> concerned that the dielectric might be bad.  I'd like
> to use something that remains flexible so that I could
> remove the cap if necessary.
>
> I've also heard that out-gassing occurs as it dries
> and that the residue might be of concern if it
> condenses on the inside of the coil.
>
> Need I worry about using this material in a coil?
>
> Thanks,
>
> Curt.