Re: Constructing HV Supply Oil Tank - PVC

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

Original poster: "Daniel Hess by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhess1-at-us.ibm-dot-com>





Daniel;

I've used hard-gray PVC to make rectangular tanks for poly/foil capacitors.
The stuff is available from plastic supply houses and is reasonably priced.
(I think I paid $80.00 for a .25" x 4 x 8' sheet but that was 3-4 years
ago.)

To bond the pieces I used the PVC cement that's used to bond the electrical
PVC conduit, found in the electrical dept. at Home Depot, not the plumbing
PVC cement. Believe it's made by the same folks who make the plumbing
cement but this stuff is gray, like the PVC itself.

The stuff goes on thick & gooey but shrinks as it cures. It bonds
remarkably well. After 24 hours I gave all the seams a second coat of
cement just to be sure they were liquid-tight.

For a cover seal I ran a small bead of standard RTV silicone around the top
edge of the box, covered it with waxed paper, placed the cover on top and
added a weight to smoosh the RTV. After 48 hours I removed the wax paper. I
used a series of #2 wood screws every 2" about the perimeter (I was driving
these into 1/4" wide plastic) and it was a lot of work but it did seal
well. Sometimes I wondered if I should have just used a suitcase type clasp
to hold the lid down.

Soon after I built these caps I segued into the blossoming MMC cap idea and
have not gone back to PVC/poly/foil/oil so as far as oil contamination from
the PVC, I didn't have them long enough to determine if this was a problem.
As you said, the stuff is easy to work with, cut, sand, drill, tap, paint
and so on but boy, does it ever generate static! If I ever find time to
build a Wimshurst generator I think I will use this PVC instead of glass
disks.

Regards,

Daniel

"Tesla list" <tesla-at-pupman-dot-com> on 05/07/2003 12:21:37 PM

To:    tesla-at-pupman-dot-com
cc:
Subject:    Constructing HV Supply Oil Tank - PVC



Original poster: "Mccauley, Daniel H by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>


I'm going to be building a 70kV HV supply in which an X-Ray transformer and
diodes will be submerged in oil.  This will be
for an experimental high voltage CW coil i'm planning to build.

I was planning on building my own oil tank using standard Type I PVC.  The
material is extremely easy to machine and is bonded instantly with Loctite
Super-Plastic Adhesive (i forget the actual number of the adhesive).
Also, all joints would be sealed as well to prevent any oil leaks and the
top cover would attach using an gasket type
seal.

The Captain