Re. Home-brew Capacitors

>Original Poster: "Steve Young" <youngs-at-konnections-dot-com> 
>1) Other than the heat seal "ruffles", do the Associated Bag Co. bags
>appear to be relatively defect free - no pinholes or thickness variations?

The sheet thickness seems to be  consistent from bag to bag, although
I've not checked too many.  Still, I doubt it's significant.  While there
are no pinholes, almost every bag has at least one little spec of flotsom
embedded within or on top of the plastic.  I don't know how significant
these are.  These were not manufactured in cleanroom conditions!  I'm
counting using multiple thin dielectric layers between plates so that
defects can't line up.  Hopefully defects won't become hot during
operation, although the more I think about it, the more that sounds bad.
Had I had the forethought to request samples prior to my purchase, I
might have continued to look elsewhere, though the requisite 13" width
seems to be an uncommon product.

>2) How will you easily have 3 sheets between plates?  Foil in bags = 2
>sheets between.  Another empty bag sandwiched between = 4 sheets between
>plates.  Are you cutting additional bags into halves for the single 3rd
>sheet, just using poly sheeting, or is every other bag actually a bag
>inside a bag?  Why did you decide on 3 vs 2 sheets?

My original plan was to use 1.5 mil bags, with an empty bag between each
pair of foil-filled bags, 4 x 1.5mils = 6 mils dielectric.  Using the 2
mil bags required 3 thicknesses to reach the same result, so I cut off a
side and a bottom of the empty bags, using one of the two sides between
each plate-pair.

Gary Lau
Waltham, MA USA