Re: plate caps

[Terry Fritz <twftesla-at-uswest-dot-net>]

Hi Dale,

	If you take a sheet of poly and put half in water for a few days, the
submersed section will become quite cloudy from the absorbed water.  It
will dry out and return to the orginal clarity when removed from the water.
 I have never heard of anyone "baking out" poly before adding oil for a cap
but perhaps in a very humid place it would be wise?

Cheers,

	Terry

At 08:17 PM 7/31/00 +0200, you wrote:
>I was looking at specs on polypropylene the other day and noticed a moisture
>absorbtion line for polyprop.  Polypropylene absorbs moisture where as
>polyethylene doesn't.  Although I am sure it is almost neglegible.
>
>
>----- Original Message -----
>From: Tesla list <tesla-at-pupman-dot-com>
>To: <tesla-at-pupman-dot-com>
>Sent: Monday, July 31, 2000 8:06 PM
>Subject: plate caps
>
>
>> Original poster: "Metlicka Marc" <mystuffs-at-orwell-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
>>
>>
>>
>>
>