Re: Oil Paper Caps.

From: 	Bert Pool[SMTP:bertpool-at-flash-dot-net]
Sent: 	Thursday, December 11, 1997 6:16 PM
To: 	Tesla List
Subject: 	Re: Oil Paper Caps.

>From: Robert Davis[SMTP:RE.Davis-at-btinternet-dot-com]
>Sent: Wednesday, December 10, 1997 3:08 PM
>To: 'tesla-at-pupman-dot-com'
>Subject: Oil Paper Caps.
>Dear All,
>I am half way through building a small coil (<100W) and want to build the
>tank capacitor.  I want to build an oil/paper cap, I will be using Kraft
>paper and Medical Grade Mineral Oil.  The capacitor will be enclosed in PVC
>tube and sealed at each end.
>I intend to seal the unit with Outdoor Silicon Sealant, the label says the
>product emits acetic acid on curing, do you think this will contaminate the
>oil unacceptably?  If so, would two part epoxy resin be better?

Use great caution with silicone sealants and oil - I have had oil soften and
ruin silicone outdoor sealant!  If you are going to use a silicone sealant,
I'd recommend the type that automotive parts stores sell for use as gasket
material for the cylinder heads - it is specifically designed for use with
oil.  And unless the oil you are using contains unusual additives, it should
work just fine.  I prefer using a really good two-part epoxy - here in the
US, JB Weld is my favorite.

>I think electrically the silicon sealant should be OK, I think also it will
>be resistant to oil leakage, is this correct?
>Does any one know the dielectric constant of oil/paper?
>Does anyone know the break down voltage of oil/paper?
>If not, I will assume break down voltage half that of oil, for safety, and
>dielectric constant to be the mean of the two.
>Thank you in advance for your help, all comments appreciated.
>Best wishes, Rob Davis (UK)