>>From sroys-at-Anchorage.ab.umd.eduFri May 3 22:10:07 1996
>Date: Fri, 3 May 1996 18:08:16 -0400 (EDT)
>A few questions...
>I just bought some clear plastic disks that are about 1" thick and were
>used as some kind of window. Is there any way to determine if these are
>lexan - I bought them thinking I could use them for a rotary gap?
>About how much copper is actually in a 100lb, 1.5kVA potential
>transformer? I was at a surplus auction the other day and someone outbid
>me for a bunch of current transformers. When I asked what he was going to
>do with them, he said he was going to burn them to get the scrap
>copper. Given this horrifying turn of events, I would like to see what I
>might be up against with the "scrappers" if they ever have any potential
>transformers. I would think most of the weight is in the iron core, but
>I just don't know.
Dry transformers in about 1 kVA and larger will yield approximately
15 to 20% of their weight in copper. I hope you talked to this fellow to
get his phone number, maybe he'd sell you one. You could offer him
the copper value and point out that you'd be saving him the recovery
On the plastic disk. Place one between a couple of chunks of wood
and slam the middle with a 2 lb. hammer. If it shatters it's
plexiglass, if the hammer bounces off it's lexan. I took a 1/4 inch
thick piece of lexan in the middle of winter at -40 degrees and did
the same test. The 2 lb. hammer just bounced off.
You might want to wear safety goggles for this test in case its not
Sorry that this test isn't the high tech scientific one expected, but
the hammer IS after all a commonly used fine tuning instrument
in many fields of high technology!
Happy coiling!, rwstephens