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Re: New cap



 Original Poster: RODERICK MAXWELL <tank-at-magnolia-dot-net> 
 
    That problem with the oil swelling up the poly has turned out to be a
 minor one compared to a new situation that has cropped up. The plastic
 casing has developed a leak! Now I'll have to retank the cap. I'm in the
 process of building a wooden tank to put the whole thing into plastic
 tank, cap and all. The wooden tank will be coated inside with epoxy
 resin to prevent leaks. This has been the most problem prone capacitor I have
ever built! Anything that could go wrong did! Thank you, and all of the list
members
 for your help. This cap has been pure Hell.
 
Hi  Rod,

Sorry to hear about your cap problems.
I donīt use PVC pipe as a cap container. Iīll tell you why. PVC is usually
somewhat brittle and the oil doesnīt make this any better. If an older PVC cap
where to fall down, it would crack, splatter and make a (not so) nice mess.
The next negative thing about PVC is that the pores of the PVC arenīt super
small. This lets minute amounts of oil weep out of your cap making you think
why the hell isnīt this thing oil tight ? And you have to glue on your end
caps, making repairs (if necessary) more difficult.

I use PP pipe. Over here in germany this stuff is somewhat cheaper than PVC
(although itīs impossible to find in sizes larger than 8") because it is used
for sewage systems inside of the house. It is less brittle and much more
impervious to oil seepage (and it doesnīt change itīs characteristics after
coming in contact with oil) than PVC. The nicest thing about these pipes is
that they have an o-ring gasket inside the ends. You just pop a cap into each
end and it is:

a.) Oil tight
b.) Vacuum tight
c.) Makes repairs on your cap a real breeze 

Aside form the above you donīt need a safety valve, because the caps fit
rather good, but should the cap burp, do to a failure the caps will just pop
off. I usually donīt seal of the vacuum port, so any kind of pressure would
leave the cap thru this vent anyway. I usually connect a small hose to this
vent and run it to a container to collect any oil that might emerge from the
hole. I seal my carrige screws (connection terminals) via a small o-ring.

You should always build a plastic container around your caps in case of
failure. I hate to think of having to rebuild everything if a cap where really
to explode and cover every thing in sight (including you) with an oily film.
Yuuuck.

More luck next time,
Coiler greets from germany,

Reinhard