Re: oil and silicone

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Your real problem is that the tub is polyethylene (PE), to which most
adhesives just don't stick very well (especially silicone).  You can rough
the PE up a bit so that it has some "tooth" for the adhesive, so you can at
least get a decent mechanical bond,but, because there isn't any connection
at a molecular level, there is a microscopically thin gap, through which oil
moves by capillary action quite nicely.

For PE, the only simple successful seals are by welding (i.e. melting the
plastic).  You can use some chemical preparations and epoxy to PE, but I
don't know if that just creates a microscopically rough surface for the
epoxy to bond to, or if it actually forms a gastight seal.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, November 12, 2001 4:21 PM
Subject: oil and silicone


> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<CTCDW-at-aol-dot-com>
>
> Hi all!
>
> I was wondering if any of you have experience with the effects of oil on
> silicone sealant. I am thinking of enclosing a transformer in a plastic
tub
> (like rubbermaid). I would like to seal the lid with silicone to prevent
oil
> leakage. will it work? or will the oil attack the silicone in some way?
>
> Chris W
>
>