Static Gap Stains

To: tesla-at-pupman-dot-com
Subject: Static Gap Stains
From: Bob Schumann <tesla-at-america-dot-com>
Date: Thu, 17 Oct 96 07:59 EDT

Hello all,

        I built the cylindrical static gap (Richard Quick type)
and have a question if anybody else has seen this happen to
their gap. I followed Richard's instructions almost to a tee
but I could never bring myself to permanently glue the copper
electrodes in place. I have access to a polishing wheel that
puts a mirror shine on them. When it is time to clean the gap,
I remove all the electrodes and polish them. I have to go 
through the re-gap and alignment routine each time but I just
can't get myself to touch sandpaper to them. Anyway...with
the electrodes out, I notice vertical brown stains on the green
SDR35 PVC innerwall between where every electrode (gap)was.

Even though I have not scrubbed at the PVC because the stains
are harmless, they will not merely wipe off.
I am just curious what does this. Is it the x-rays or UV from
the spark possisbly that affects the PVC? Such as the PVC
gets a 'sunburn'? Of course this is of no operating consequence
as the gap works as well as ever, I just wondered what did it.

Comment welcomed!
Thanks
Bob Schumann