plate caps

["Metlicka Marc" <mystuffs-at-orwell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

hello eric, all
i have built some fine plate caps using polyprop. sheet protectors,
these i got from office max. they were Avery " diamond clear " units,
these were the only ones that were made from polypropylene. office max
gave me a discount for 1200 units.
my caps were 42 plate units with 5-3.3mil protectors between each plate
giving a total of 33mil dielectric per plate. i used al. foil for the
plates but i would suggest al flashing if i to do it again, the foil was
a lot of trouble to cut,flaten and smooth.
since the sheet protectors were 8.5" by 11", each plate was 7" by 9"
with a 3" by 1" tab sticking up from the corner for the attachment
point.
i built a form from plywood that i could stack the unit in,placing two
very long big wire ties on the bottom then a polyeth. cutting board that
i found at dollar store. after stacking 42 plates alternating the tabs
side to side with five sheet protectors between each, i placed another
poly cutting board then 42 more, another cutting board, 42 more.
this gave me three caps of 42nf with a v rating low end guestimating at
500 v per mill, 16500v each. i sandwiched all these together with
cutting boards on each end, then slid it into a new five gallon bucket
with lid. i folded all the tabs up together then connected the three
caps into series with hv wire and alligator clips, then i put brass
bolts through the lid and connected the bank, this gave me a cap bank of
14nf-at-49500vac.
i filled the bucket it mineral oil and let it sit for a couple weeks,
putting a vacuum cleaner over the spout every day to suck out the air. i
built to of these and paralleled them for 24nf.
if you contact me off list i will send some pics.
if i had to do it again i would use the party cup cap design that i sent
you. placed into a 4" pvc pipe the cups are cheaper easier and perform
well.
if you still want to build the flat plater, i found a co. that sells
6mil polyeth. bags cheap. you can call 1-800-481-3600 for a catalog.
hope this helps,  marc