HV Oil & Neon

From: 	gweaver[SMTP:gweaver-at-earthlink-dot-net]
Sent: 	Friday, August 29, 1997 1:32 PM
To: 	Tesla-at-pupman-dot-com
Subject: 	HV Oil & Neon

HV Oil & Neon

I have an unpotted neon that insists on arcing along the side of one of the
high voltage coils. Today I built a plexaglass box 5" x 5" x 8" and mounted
the neon to the top inside the box.  I filled the box with oil and left
about 1/2" air space at the top.  I later had to fill the box with oil all
the way to the top because it was arcing threw the air space between the HV
terminals and the metal part of the transformer which is .375".

I tested the neon with the amp meter and I am getting 15,000. volts 50 ma.
from a 15K 30 ma transformer.  I used 32 layers of white typing paper as a
spacer between each coil to hold things on center and in place.  I connected
the neon to my 4" TC with a .005 uf cap and there is no more arcing between
the HV terminals and the metal parts of the transformer.   I am getting some
bubbles coming off the side of the high voltage coil.  This is the same coil
that was arcing before.  I can see threw the clear plastic box and the HV
coil is arcing and making the oil boil creating the bubbles.

I went into the house and returned about one hour later.  I tested the neon
again and the arcing on the side of the HV coil has stopped.  It must have
taken a few minutes for the oil to soak into the coil.  It seems to be
working fine now.  I ran the TC several times with no problems.

I decided to test the high voltage oil.  I made an adjustable spark gap and
put it in a container of HV oil.  I connected 15,000. volts across the spark
gap and turned on the power.  I adjusted the spark gap until I got the 1st
spark threw the oil.  The spark threw the oil was very thin.  I checked the
gap and got .116 with feeler guages.

When I unpotted this neon several months ago I cleaned all the metal parts
with gasoline and scraped the coils as clean as I could get them with a
knife.  The HV oil is dissolving the remaining tar that is soaked into the
coils.  After being in the oil for 2 hours the oil is no longer the clear
clean looking oil it once was.  The HV oil now looks like coffee.

I am not sure what type of glue is best for glueing plexaglass together.
The plexaglass is 1/2 " thick and smells like polycarbonate when I ruff cut
the pieces on the table saw. After finishing the 6 sides of the plastic box
on the milling machine I assembled the box and used rubber bands to hold it
together leaving off the top.  I put several drops of acetone on each seam
and let it dry for 1 hour. I tried as hard as I could to pull the box apart
by hand but I couldn't.  I beat the box with a rubber hammer and it stayed

Gary Weaver