Gee...

I sure hope I spelled that right!

Anyway, Welcome to this new Yahoo Group for the casual experimenter
in Vacuum or High Vacuum (from now on Vac or HiVac).

Searching the web I've found a few places for more experienced vacuum
workers that seem to really get into the Physics of what and how the
molecules do what they do under low pressures. I've made a few
requests on some of those lists and I either get a full-blown snow-
job or an offer to sell me just the right do-dad for only a few
thousand dollars. That kinda leaves me without a place to chat with
folks that have some knowledge and are willing to share it.

I am interested in HiVac in order to put together an Aluminizing
chamber for telescope mirrors. I've been gathering parts for several
years in order to build my system and have a barn full of goodies but
was still looking for an 18 inch Bell Jar until last week when I
found a surplus 24 inch SYSTEM. I will be travelling to Eastern PA
this weekend to pick it up and will keep a running description on
here (assuming there is any interest and/or members). I've seen
Aluminum vaporized onto glass before and "it ain't rocket science".
It's a fairly simple process but there are things to be aware of and
to watch out for.

So...

Let's get together and have some friendly discussions on what works,
what doesn't, things to watch out for, things to sell, trade, etc.
I'm moderator only in the sense that I've started this group. I'll
pretty much leave the daily running to the members but will step in
if I'm asked or if I see a need... other than that, it's your group
to use.

Have fun, be kind, learn, teach, participate.

Ken Hunter

Hi Guys...

I've posted some photo's to the group in a folder named "Ken's junque
shop". There's one of me and a SILO top that I have been lugging
around for a while, a few of some vacuum valves, diffusion pumps and
condenser baffle units as well as one of the 20 inch baseplates I
have been trying to find an 18 inch bell jar for. There are also 4
photo's of the vacuum system that I'll be picking up in Pa this
coming week. It is a 24 inch bell jar with all the valves, turbo pump
etc. Only thing missing is a roughing pump. I have a HyVac that I
think will work but it might be a bit under-rated for the turbo. I'll
just have to see how it does.

Now it's your turn...

Open up a folder and post your photo's then give us a description of
what you're doing or would like to do. Personal photo's are nice to
have also so we can see who we are chatting with.

Have fun!

Ken Hunter

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In James Lerch's system he uses an adjustable valve to "tune" the
amount of cooling derived from an air conditioning compressor to cool
his cold trap... I have a similar cold trap (3 actually) that I have
not set up yet. They came with compressors, expansion chambers and
capillary tubes.

Should I go ahead and try using the capillary tubes or change over to
an adjustable valve? I would have to re-weld, silver solder the
capillary tubes back into the chambers to get them working.

Does the tubing aperature actually have to be changed if the
compressed liquid type is changed? I'm not sure what the original
refrigerant was but the system is fairly ancient. Most likely I'd
have to change refrigerent types to a newer approved refrigerant.

Anybody out there have any ideas on what would be the best way to
proceed?

Looks like I might need to start a "compressed gasses" group...

Ken Hunter

I've added James Lerch's web site link to the Group Links. If you
have a web site that you'd like to add... please do!

Ken Hunter

Hi...

It's been a while since anyone (me) posted. We now have 12 members,
but not much participation. Should I keep the Group open or let it
die?

I've returned from Eastern PA with a vacuum coating system on the
back of the trailer. Unfortunately, I contracted a bad cold during
the loading of the equipment and have been bedridden for most of the
last few days. It's still where it was parked Wednesday and I haven't
been outside since that time.

There will be a lot to do to make the system operational. Originally
it was a wafer handling and coating chamber for making Integrated
circuits. Most of the wafer handling equipment, gauges etc were taken
off the rack before I purchased it but I was able to retrieve the
electronics necessary for making the gauges and turbo pump work. I'll
need to dis-assemble and clean everything as there is no way of
knowing what kind of toxic materials may be lurking in the thing. A
complete re-wiring will also be necessary as the original machine was
controlled by computer. So, I have my work cut out for me.

What are you up to these days?

Ken Hunter

Ken ; hello , just joined your group , I confess I dont know much
about vacuum coating mirrors, thats part of the reason I joined.I do
however calibrate vacuum gages at work for a liveing.So if I can be
of any help, give me a holler.I hope this group makes it.Coating ones
own mirrors, isnt a pretty wide spread practice , but it is
interesting. Andy

--- In VacuumX@..., "Ken Hunter <atm_ken_hunter@y...>"
<atm_ken_hunter@y...> wrote:

Hi...

It's been a while since anyone (me) posted. We now have 12 members,
but not much participation. Should I keep the Group open or let it
die?

I've returned from Eastern PA with a vacuum coating system on the
back of the trailer. Unfortunately, I contracted a bad cold during
the loading of the equipment and have been bedridden for most of

the

last few days. It's still where it was parked Wednesday and I

haven't

been outside since that time.

There will be a lot to do to make the system operational.

Originally

it was a wafer handling and coating chamber for making Integrated
circuits. Most of the wafer handling equipment, gauges etc were

taken

off the rack before I purchased it but I was able to retrieve the
electronics necessary for making the gauges and turbo pump work.

I'll

need to dis-assemble and clean everything as there is no way of
knowing what kind of toxic materials may be lurking in the thing. A
complete re-wiring will also be necessary as the original machine

was

controlled by computer. So, I have my work cut out for me.

What are you up to these days?

Ken Hunter

Hi Andy...

Welcome to the Group. I'm sure that your expertise can be of help to
some of us as we muddle through. Where are you located? I'm thinking
Australia for some reason. (Am I close?) Tell us more about what you
do at work and please post a photo of yourself or favorite project or
both in the sections to the left. If you have access to surplus
gauges, parts or supplies, let that be known also... Let's see if we
can keep this thing going.

Do you work on Gauge Controllers as well as the gauges? What models
do you handle and recommend?

There's a lot of folks that use Vacuum pumps, gauges, etc for making
Neon signs and other projects that may have some needed information
or may be able to pick some up here as well. You never know who will
show up or what they will bring with them.

Ken Hunter

Ken ; hello I work in a foundry, Im the lead calibrator technician,
we have 5 small units we use to pull up to 30 lbs of vacuum to test
for gas in the aluminum.Calibrateing them is pretty straight
forward.I live in north east ohio.As for parts well, I dont actually
own one myself.But Ill be glad to help as much as I can as far as
where to purchase the gages goes or the testing equipment, or even
how to test for accuracy of the gage.I know a year or so ago, I went
looking for some one who might have a coating chamber, found exactly
zero, so Im sure this group can serve a usefull function in the atm
universe. Andy

--- In VacuumX@..., "Ken Hunter <atm_ken_hunter@y...>"
<atm_ken_hunter@y...> wrote:

Hi Andy...

Welcome to the Group. I'm sure that your expertise can be of help

to

some of us as we muddle through. Where are you located? I'm

thinking

Australia for some reason. (Am I close?) Tell us more about what

you

do at work and please post a photo of yourself or favorite project

or

both in the sections to the left. If you have access to surplus
gauges, parts or supplies, let that be known also... Let's see if

we

can keep this thing going.

Do you work on Gauge Controllers as well as the gauges? What models
do you handle and recommend?

There's a lot of folks that use Vacuum pumps, gauges, etc for

making

Neon signs and other projects that may have some needed information
or may be able to pick some up here as well. You never know who

will

show up or what they will bring with them.

Ken Hunter

开云体育

Thanks Andy for the Bio and info on your job... Hmmm, working in a
foundry sounds interesting. Bet that you'd be able to make your own
forks for a fork mount there???

Yeah, I hear you about finding a coating chamber. I'm doing a 26.5
inch mirror and NOBODY can Aluminize it for less than a small fortune
and I'd have to stand in line forever so decided I'd put one
together... Found a 29-1/2 inch tank and a bunch of diffusion pumps
and assorted parts still sitting in the barn. Got a few guys here
interested for a while but getting it all together has been less than
fast. Not even half-fast ;0) so I'm pretty much on my own again.

Then a couple weeks ago I was contacted by a guy that had bought a
system for some of the goodies and what was left over was what I was
looking for so we made a deal and I went to PA to pick it up last
week. Once I get it together, I'm going to do Aluminizing and
overcoating, maybe thin films too, for ATM's at a reasonable price
and fast turn around. It'll be my retirement project and a way to
earn some spending money without dipping into what's left of the
retirement funds...

Take care.

Ken Hunter

开云体育

Hi James,

Thanks for the informative post on the Capillary tube usage.

I don't know much about those things but I'd have to guess that the
capillary tubes I have are about 6-8 feet long (in a 3 inch dia
coil), maybe 1/16th inch OD and have a hole so tiny that I can't blow
air through them. I can take some photo's later but doubt that you'll
be able to see anything.

The 3 compressor units came on a frame with my 3 diffusion pumps,
valves etc. and 2 of thecapillary tubes were broken off at the point
where they were (looks like) soldered into the expansion chamber. I
haven't taken them apart to see what's inside but I imagine just a
couple inches of the capillary tube is sticking into the chamber.

Thought I could re-solder (maybe have to silver solder) the Capillary
tube back into the chamber and give it a go to see what happens. I
think I have a photo of the valves that also shows the compressors...

I'll need to find a set of A/C gauges to give it a try. Interesting
that you said just to give it a shot of freon... I gather the idea is
to get the maximum pressure differential across the chamber while
still delivering a compressed liquid to the chamber to be expanded.

I'll try to get some measurements of the Capillary tubing and some
photo's this week if it get's warm enough to get outside to the barn.

There sure is a lot to learn.

Ken Hunter

On Sun, 2003-01-26 at 08:32, Ken Hunter wrote:

Hi James,

Thanks for the informative post on the Capillary tube usage.

I don't know much about those things but I'd have to guess that the
capillary tubes I have are about 6-8 feet long (in a 3 inch dia
coil), maybe 1/16th inch OD and have a hole so tiny that I can't blow
air through them. I can take some photo's later but doubt that you'll
be able to see anything.

The 3 compressor units came on a frame with my 3 diffusion pumps,
valves etc. and 2 of thecapillary tubes were broken off at the point
where they were (looks like) soldered into the expansion chamber. I
haven't taken them apart to see what's inside but I imagine just a
couple inches of the capillary tube is sticking into the chamber.

Thought I could re-solder (maybe have to silver solder) the Capillary
tube back into the chamber and give it a go to see what happens. I
think I have a photo of the valves that also shows the compressors...

Yes - it is necessary to silver solder. If you just use a tin lead (or
whatever the newer version is) you run a severe risk of failure. Silver
solder done well has a tensile that is higher than your base material
where regular tin lead (I think the new version is zinc tin???) is
considerably weaker (about 5000# tensile if my information is correct
(it was for 37% Sn solder)).

I'll need to find a set of A/C gauges to give it a try. Interesting
that you said just to give it a shot of freon... I gather the idea is
to get the maximum pressure differential across the chamber while
still delivering a compressed liquid to the chamber to be expanded.

I'll try to get some measurements of the Capillary tubing and some
photo's this week if it get's warm enough to get outside to the barn.

There sure is a lot to learn.

Maybe I should introduce myself. I am a machinist with a fair amount of
welding experience that also likes to tinker. Astronomy has been
something that I have wanted to get into for a long time so I am
gathering information and we will see from there.

Has anyone here silvered a mirror and then coated it?

Just wondering how something like that would work out.

Darald

Hi Darald,

James is the ONE to ask about silvering... He has done quite a few
mirrors that way and I believe he's made a few attempts at coating
them to prevent tarnishing. I'd bet that he can give you all the info
you need to Silver then give you his reasons for Aluminizing too...

Check out his web page. The URL for his web site is in the LINKS
section

<------- over there

Ken Hunter

--- In VacuumX@..., Darald Bantel <dbantel@t...> wrote:

On Sun, 2003-01-26 at 08:32, Ken Hunter wrote:

Hi James,

Thanks for the informative post on the Capillary tube usage.

I don't know much about those things but I'd have to guess that

the

capillary tubes I have are about 6-8 feet long (in a 3 inch dia
coil), maybe 1/16th inch OD and have a hole so tiny that I can't

blow

air through them. I can take some photo's later but doubt that

you'll

be able to see anything.

The 3 compressor units came on a frame with my 3 diffusion pumps,
valves etc. and 2 of thecapillary tubes were broken off at the

point

where they were (looks like) soldered into the expansion chamber.

I

haven't taken them apart to see what's inside but I imagine just

a

couple inches of the capillary tube is sticking into the chamber.

Thought I could re-solder (maybe have to silver solder) the

Capillary

tube back into the chamber and give it a go to see what happens.

I

think I have a photo of the valves that also shows the

compressors...

Yes - it is necessary to silver solder. If you just use a tin lead

(or

whatever the newer version is) you run a severe risk of failure.

Silver

solder done well has a tensile that is higher than your base

material

where regular tin lead (I think the new version is zinc tin???) is
considerably weaker (about 5000# tensile if my information is

correct

(it was for 37% Sn solder)).

I'll need to find a set of A/C gauges to give it a try.

Interesting

that you said just to give it a shot of freon... I gather the

idea is

to get the maximum pressure differential across the chamber while
still delivering a compressed liquid to the chamber to be

expanded.

I'll try to get some measurements of the Capillary tubing and

some

photo's this week if it get's warm enough to get outside to the

barn.

There sure is a lot to learn.

Maybe I should introduce myself. I am a machinist with a fair

amount of

welding experience that also likes to tinker. Astronomy has been
something that I have wanted to get into for a long time so I am
gathering information and we will see from there.

Has anyone here silvered a mirror and then coated it?

Just wondering how something like that would work out.

Darald

Greetings All,

Thanks to Peter Baird, I've added the option in my simulation code to
support multiple evaporating rings. An interesting result from this
experiment shows that it should be feasible to construct a 12" diameter by
5" tall chamber. The downside of course is the need for 19 separate
tungsten evaporating coils!

While this might not be feasible for such a small chamber, when constructing
my next chamber (20-30" diameter) it might just be worth the effort! The
main benefit of such a short chamber would be the reduction in chamber
volume, thus allowing the use of smaller pumps and faster pump down time!

To implement such a wiring nightmare might be interesting, but I'm wondering
if I might be able to mass produce some Ceramic electric pass throughs.
Something that would just require drilling a hole in the chamber, then drop
the pass thru in, and seal with an O-ring.. (still working out the details
:) Anyone ever seen anything like this?

new Near Field Evaporative Simulator code is available from here:
(8.6KB)

Take Care,
James Lerch
(My telescope construction,testing, and coating
site)

James,

In my photo folder I have added something you might want to consider.
It is a common item found at most any Hardware store and it's called
a "wellnut". They come in various sizes and I imagine that it could
be used as a cheap feedthrough for electrical purposes. I don't have
an assembled system yet to test the idea but you do! It would work
just like the botttom plug on a small boat. Put it into a hole, pass
a bolt through and tighten it up. The rubber will compress sealing
against the smooth shoulder on the bolt and the (hopefully smooth)
sides of the hole. The pass-through bolt becomes the conductor.

Ken Hunter

--- In VacuumX@..., "James Lerch" <jlerch1@t...> wrote:

To implement such a wiring nightmare might be interesting, but I'm

wondering

if I might be able to mass produce some Ceramic electric pass

throughs.

Something that would just require drilling a hole in the chamber,

then drop

the pass thru in, and seal with an O-ring.. (still working out the

details

:) Anyone ever seen anything like this?

James,

I've added a photo to my folder that might be what you are asking
for. It's a common item found at hardware stores and is called
a "wellnut". I imagine it would work like the hole plug at the bottom
of a small boat. You drill the hole, put in the wellnut, insert the
bolt and tighten. The rubber compressess and tightens against the
sholder on the bolt and the sides of the hole. The bolt becomes the
conductor. It's available in various sizes.

Ken Hunter

--- In VacuumX@..., "James Lerch" <jlerch1@t...> wrote:

To implement such a wiring nightmare might be interesting, but I'm

wondering

if I might be able to mass produce some Ceramic electric pass

throughs.

Something that would just require drilling a hole in the chamber,

then drop

the pass thru in, and seal with an O-ring.. (still working out the

details

:) Anyone ever seen anything like this?

Changed the Group photo so you wouldn't have to chase down the photo
of the Feed-Thru idea I have...

If you have any photo's that you would like to submit to the Group,
please do. I'll rotate all submitted photo's through the Group's home
page as time permits.

Ken Hunter

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