My project is the gradual restoration of an old, (~1960 I'm
guessing)
Kinney vacuum coater, (Type SC-3).
The system is based on a 2" diffusion pump, 12" dia X 12" tall bell
jar, and a Sargent-Welch 1403 roughing pump.
To date, my progress has been to disassemble and clean up the
diffusion pump. It had the appearance and smell on the inside of
being a crude oil cracking apparatus. I used oven cleaner, (not
wanting to mess with hot lye solutions) followed by distilled water
and then acetone to clean it up. I replaced all the seals with new
Viton O rings. I cleaned up and changed the oil in the roughing pump
which seems to be in very good condition.
At this point I decided to see were I stood with the system. Without
further disassembly and cleaning, (I was worried about the condition
of the rubber diaphragms in the various diaphragm valves, the outside
edges look cracked, but I didn't want to mess with them unless I
had
to), I started roughing down the system.
I think it went surprisingly well for such and old piece of
equipment. I was able to get the system down to about 10^-2 torr,
which surprised me because as far as I can tell the 1403 roughing
pump is a one stage pump and I wouldn't expect it to get much
below 1
torr. The pressure was monitored using a Stokes McLeod gauge. One of
the three installed thermocouple gauges seemed to be functioning. I
suspect that the other two gauge tubes, (Type 531) are not working.
The discharge gauge, which I'm assuming was installed in the bell
jar
base plate, because there was a vacant hole, is missing. My guess it
was a cold cathode ion gauge. I have a Kinney type KDG gauge head a
Varian 524-2 gauge head and a NRC type 507 ionization gauge sitting
in a box of parts I got with the system, along with a CVC Autovac
3294A gauge controller and a NRC 724 Gauge controller. Which gauge
head goes with which controller I am not at all certain. I also
picked up a Bendix (CVC?) GP-310 Pirani gauge controller with no
sensor head at the MIT flea marker Sunday just because it was sitting
there for $10.
The immediate questions I have concern the next step. I feel that I
am in the pressure realm that I can consider turning on the diffusion
pump. Initiayl I charged the diffusion pump with an unknown silicon
oil that I removed from an old 4" CVC system that I have waiting for
possible restoration. Then I got to thinking that this old Kinney
system was probably designed for a hydrocarbon diffusion oil and the
heater came into question. The heater is a Chromalox HSP 31, 115V,
100W disc heater. There is no controller or thermostat on the heater
nor anyway to measure the heater temperature. What diffusion pump oil
should I use? I might add that there seems to be no baffle between
the diffusion pump and the bell jar, just a gate valve.
Intrumentation. What sensor head goes with what controller? A cheap
source of type 531 T/C gauge heads. The same for a Pirani type GP-003
sensor tube. Does anyone have any recollection of this Kinney system?
This is a "back burner" type of project, going slow as I collect
information and pieces.
My interest in vacuum coating has to do with small acoustical sensors
and sources. For example, I am currently working on a miniature
electrostatic sound source which incorporates a slightly conductive
very thin, (~.00006 inch) Mylar diaphragm and perforated thin metal
stators. Currently I am making the diaphragms "conductive", (about
10K ohms over 1") by applying powdered graphite to them. They work,
but this doesn't seem very elegant or controllable. If I get the
vacuum coating system running, my next series of questions may be
concerning how to conductively coat mylar without melting it,
(radiating heat). The Kinney system is also set up with carbon
coating capabilities. Also, because these electrostatic sources I am
working on are to be used in a very high magnetic field, (MRI) I have
a need to minimize metal in their construction, (eddy currents), so a
metalized stator might have advantages. Envisioned future uses for
vacuum coating might concern capacitance micro phones, again
metalized diaphragms and stators, and plasma clean/etching sounds
interesting because I am forever trying to adhesively bond polar
polymers, (nylon, Delrin, polyethelene, Teflon, etc)
Thanks for any guidance
ExpTec
DBA Experimental Technique
