Re: Blown Rolled "Hull" Capacitor Discussion

To: tesla-at-grendel.objinc-dot-com
Subject: Re: Blown Rolled "Hull" Capacitor Discussion
From: jim.fosse-at-bdt-dot-com (jim fosse)
Date: Fri, 1 Mar 96 23:00 PST
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>Scott,
>
>One of the problems that you can run into with PVC pipe and PVC end caps is 
>that if you try to use a good vacuum pump, you can suck air THROUGH the PVC 
>end caps!  I put a vacuum pump on one of my caps after filling with oil to 
>see if I might be able to coax some additional air out from between the 
>layers of plastic and aluminum.  I was pleased to see a lot of bubbles 
>rising up through the oil.... only they never stopped.  I became suspicious
and 
>poured some oil into a capacitor housing that had no cap in it and connected 
>the pump.  Sure enough, the vacuum pump could pull air right through the PVC 
>plastic end cap.  Although a vacuum can pull air through the plastic, oil 
>will not leak out.  The result of trying to use a vacuum pump was that I 
>ended up sucking millions of air bubbles INTO my capacitor, not what I was 
>trying for.
>Anyone else tried this with better luck?
>
>Bert
>
Bert,
        A classic problem in vacuum. the chamber is porous! Paint it. The
common vacuum solution is to use shellac.

                        jim