Re: weird Sharpie residue
Was the Sharpie a "dry marker" or a
"permanent marker?" I imagine the residue from a dry marker would
be carbon and that the solvent from a permanent marker to be much
more aggressive. I suspect you have permanently etched the glass.
Salt from fingerprints will etch the glass as will any alkaline
material.
Don
On 2/21/15 9:05 PM, Andrew Aurigema eosraptor@... [VacuumX]
wrote:
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Show quoted text
Moving up in chemical agression towards the dye would be
methyl cloride..... or methyline cloride.... found in Dads Old
Fasion Paint Stripper. ?Neither are caustic.
Sent via the Samsung
Galaxy Note? II, an AT&T 4G LTE smartphone
-------- Original message --------
Date:02/21/2015 11:43 AM (GMT-05:00)
Cc: David Collins
Subject: [VacuumX] weird Sharpie residue
?
Interesting residue
from a Sharpie or Magic Marker on a mirror that I cannot
remove before aluminizing it!
Here's how it
happened: David C is making a 12.5" mirror and based on
ronchi and foucault/couder zonal readings, it looks pretty
good. We tried using a wire test, and to do so, I used a
Magic Marker to draw a chord or diameter and marked some
points on it. (Saw professionals at NuTek near Baltimore
do the same thing, thought it couldn't hurt.
We
then tried to do star testing. However, trying to do that
outside when uncoated was a nightmare. So I figured it
would be asier if I did a quick-and-dirty coating in our
Consolidated Electrodynamics vacuum chamber and alumizer,
vintage mid-1960s. Literally "quick and dirty" because I
didn't even wash it off. The aluminum stuck just fine, but
you could see our fingerprints and the Sharpie line
through the aluminum. Did some more testing.
Yesterday,
we decided to do a real coating. ?So we got out the 'green
river' and the paper towels and stood outside in the snow
and cold and watched Venus and Mars do their slow evening
dance whille the aluminum came off, which it did.
Then we took the
mirror into the CCCC kitchen to clean off anything
remaining (and warm up) using our regular agents: Alconox
powder and powdered USP calcium carbonate (separately)
with water and cotton balls.
Guess
what?
We could still see,
clearly, where I had drawn the line with the permanent
marker, despite repeated washings and scrubbings.
We even tried laquer
thinner. ?No change. We haven't tried acetone, because we
were out, and intend to do so, but at this point I'm not
sure it will work either... Methyl Ethyl Ketone? I sure
hope it doesn't need polishing again, because figuring a
12.5" mirror is a WHOLE lot of work.
Weird.
Anybody
have comments or ideas?
?
Guy Brandenburg,
Washington, DC?
guysmathastro.wordpress.com
============================
|
Re: weird Sharpie residue
I doubt it.? ? Guy Brandenburg, Washington, DC?
http://gfbrandenburg.wordpress.com/
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
============================
From: "Thomas Janstrom t_janstrom@... [VacuumX]" To: VacuumX@...
Sent: Saturday, February 21, 2015 8:37 PM
Subject: Re: [VacuumX] weird Sharpie residue
?
Guy,
Are you sure the marker tip didn't in fact "polish" a groove into
the surface? Some of the felt tip markers use fibre glass for the
tip so it might be more abrasive than you expect. Just a thought.
Thomas.
On 22/02/2015 2:43 AM, Guy Brandenburg gfbrandenburg@...
[VacuumX] wrote:
?
Interesting
residue from a Sharpie or Magic Marker on a mirror
that I cannot remove before aluminizing it!
Here's how it
happened: David C is making a 12.5" mirror and based
on ronchi and foucault/couder zonal readings, it looks
pretty good. We tried using a wire test, and to do so,
I used a Magic Marker to draw a chord or diameter and
marked some points on it. (Saw professionals at NuTek
near Baltimore do the same thing, thought it couldn't
hurt.
We
then tried to do star testing. However, trying to do
that outside when uncoated was a nightmare. So I
figured it would be asier if I did a quick-and-dirty
coating in our Consolidated Electrodynamics vacuum
chamber and alumizer, vintage mid-1960s. Literally
"quick and dirty" because I didn't even wash it off.
The aluminum stuck just fine, but you could see our
fingerprints and the Sharpie line through the
aluminum. Did some more testing.
Yesterday,
we decided to do a real coating. ?So we got out the
'green river' and the paper towels and stood outside
in the snow and cold and watched Venus and Mars do
their slow evening dance whille the aluminum came off,
which it did.
Then we took the
mirror into the CCCC kitchen to clean off anything
remaining (and warm up) using our regular agents:
Alconox powder and powdered USP calcium carbonate
(separately) with water and cotton balls.
Guess
what?
We could still
see, clearly, where I had drawn the line with the
permanent marker, despite repeated washings and
scrubbings.
We even tried
laquer thinner. ?No change. We haven't tried acetone,
because we were out, and intend to do so, but at this
point I'm not sure it will work either... Methyl Ethyl
Ketone? I sure hope it doesn't need polishing again,
because figuring a 12.5" mirror is a WHOLE lot of
work.
Weird.
Anybody
have comments or ideas?
?
Guy
Brandenburg, Washington, DC?
guysmathastro.wordpress.com
============================
|
Re: weird Sharpie residue
The surface roughness of the glass might be a factor.
Christopher Erickson
Consulting Engineer
Summit Kinetics
Waikoloa, HI 96738
www.summitkinetics.com
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Show quoted text
-----Original Message----- From: VacuumX@... [mailto:VacuumX@...] Sent: Saturday, February 21, 2015 3:52 PM To: VacuumX@... Subject: Re: [VacuumX] weird Sharpie residue On 02/21/2015 05:37 PM, Thomas Janstrom t_janstrom@... [VacuumX] wrote: Guy,
Are you sure the marker tip didn't in fact "polish" a groove into the
surface? Some of the felt tip markers use fibre glass for the tip so it
might be more abrasive than you expect. Just a thought.
Thomas. I wonder if the type of glass might be a factor? -- Kirk Wallace ------------------------------------ Posted by: Kirk Wallace <kwallace@...> ------------------------------------ ------------------------------------ Yahoo Groups Links
|
Re: weird Sharpie residue
Moving up in chemical agression towards the dye would be methyl cloride..... or methyline cloride.... found in Dads Old Fasion Paint Stripper. ?Neither are caustic.
Sent via the Samsung Galaxy Note? II, an AT&T 4G LTE smartphone
toggle quoted message
Show quoted text
-------- Original message -------- From: "Guy Brandenburg gfbrandenburg@... [VacuumX]" Date:02/21/2015 11:43 AM (GMT-05:00) To: vacuumx@... Cc: David Collins Subject: [VacuumX] weird Sharpie residue
?
Interesting residue from a Sharpie or Magic Marker on a mirror that I cannot remove before aluminizing it!
Here's how it happened: David C is making a 12.5" mirror and based on ronchi and foucault/couder zonal readings, it looks pretty good. We tried using a wire test, and to do so, I used a Magic Marker to draw a chord or diameter and marked some points on it. (Saw professionals at NuTek near Baltimore do the same thing, thought it couldn't hurt.
We then tried to do star testing. However, trying to do that outside when uncoated was a nightmare. So I figured it would be asier if I did a quick-and-dirty coating in our Consolidated Electrodynamics vacuum chamber and alumizer, vintage mid-1960s. Literally "quick and dirty" because I didn't even wash it off. The aluminum stuck just fine, but you could see our fingerprints and the Sharpie line through the aluminum. Did some more testing.
Yesterday, we decided to do a real coating. ?So we got out the 'green river' and the paper towels and stood outside in the snow and cold and watched Venus and Mars do their slow evening dance whille the aluminum came off, which it did.
Then we took the mirror into the CCCC kitchen to clean off anything remaining (and warm up) using our regular agents: Alconox powder and powdered USP calcium carbonate (separately) with water and cotton balls.
Guess what?
We could still see, clearly, where I had drawn the line with the permanent marker, despite repeated washings and scrubbings.
We even tried laquer thinner. ?No change. We haven't tried acetone, because we were out, and intend to do so, but at this point I'm not sure it will work either... Methyl Ethyl Ketone? I sure hope it doesn't need polishing again, because figuring a 12.5" mirror is a WHOLE lot of work.
Weird.
Anybody have comments or ideas? ? Guy Brandenburg, Washington, DC? guysmathastro.wordpress.com
http://gfbrandenburg.wordpress.com/
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
============================
|
Re: weird Sharpie residue
On 02/21/2015 05:37 PM, Thomas Janstrom t_janstrom@... [VacuumX] wrote: Guy,
Are you sure the marker tip didn't in fact "polish" a groove into the
surface? Some of the felt tip markers use fibre glass for the tip so it
might be more abrasive than you expect. Just a thought.
Thomas. I wonder if the type of glass might be a factor? -- Kirk Wallace
|
Re: weird Sharpie residue
Guy,
Are you sure the marker tip didn't in fact "polish" a groove into
the surface? Some of the felt tip markers use fibre glass for the
tip so it might be more abrasive than you expect. Just a thought.
Thomas.
On 22/02/2015 2:43 AM, Guy Brandenburg gfbrandenburg@...
[VacuumX] wrote:
toggle quoted message
Show quoted text
?
Interesting
residue from a Sharpie or Magic Marker on a mirror
that I cannot remove before aluminizing it!
Here's how it
happened: David C is making a 12.5" mirror and based
on ronchi and foucault/couder zonal readings, it looks
pretty good. We tried using a wire test, and to do so,
I used a Magic Marker to draw a chord or diameter and
marked some points on it. (Saw professionals at NuTek
near Baltimore do the same thing, thought it couldn't
hurt.
We
then tried to do star testing. However, trying to do
that outside when uncoated was a nightmare. So I
figured it would be asier if I did a quick-and-dirty
coating in our Consolidated Electrodynamics vacuum
chamber and alumizer, vintage mid-1960s. Literally
"quick and dirty" because I didn't even wash it off.
The aluminum stuck just fine, but you could see our
fingerprints and the Sharpie line through the
aluminum. Did some more testing.
Yesterday,
we decided to do a real coating. ?So we got out the
'green river' and the paper towels and stood outside
in the snow and cold and watched Venus and Mars do
their slow evening dance whille the aluminum came off,
which it did.
Then we took the
mirror into the CCCC kitchen to clean off anything
remaining (and warm up) using our regular agents:
Alconox powder and powdered USP calcium carbonate
(separately) with water and cotton balls.
Guess
what?
We could still
see, clearly, where I had drawn the line with the
permanent marker, despite repeated washings and
scrubbings.
We even tried
laquer thinner. ?No change. We haven't tried acetone,
because we were out, and intend to do so, but at this
point I'm not sure it will work either... Methyl Ethyl
Ketone? I sure hope it doesn't need polishing again,
because figuring a 12.5" mirror is a WHOLE lot of
work.
Weird.
Anybody
have comments or ideas?
?
Guy
Brandenburg, Washington, DC?
guysmathastro.wordpress.com
============================
|
Interesting residue from a Sharpie or Magic Marker on a mirror that I cannot remove before aluminizing it!
Here's how it happened: David C is making a 12.5" mirror and based on ronchi and foucault/couder zonal readings, it looks pretty good. We tried using a wire test, and to do so, I used a Magic Marker to draw a chord or diameter and marked some points on it. (Saw professionals at NuTek near Baltimore do the same thing, thought it couldn't hurt.
We then tried to do star testing. However, trying to do that outside when uncoated was a nightmare. So I figured it would be asier if I did a quick-and-dirty coating in our Consolidated Electrodynamics vacuum chamber and alumizer, vintage mid-1960s. Literally "quick and dirty" because I didn't even wash it off. The aluminum stuck just fine, but you could see our fingerprints and the Sharpie line through the aluminum. Did some more testing.
Yesterday, we decided to do a real coating. ?So we got out the 'green river' and the paper towels and stood outside in the snow and cold and watched Venus and Mars do their slow evening dance whille the aluminum came off, which it did.
Then we took the mirror into the CCCC kitchen to clean off anything remaining (and warm up) using our regular agents: Alconox powder and powdered USP calcium carbonate (separately) with water and cotton balls.
Guess what?
We could still see, clearly, where I had drawn the line with the permanent marker, despite repeated washings and scrubbings.
We even tried laquer thinner. ?No change. We haven't tried acetone, because we were out, and intend to do so, but at this point I'm not sure it will work either... Methyl Ethyl Ketone? I sure hope it doesn't need polishing again, because figuring a 12.5" mirror is a WHOLE lot of work.
Weird.
Anybody have comments or ideas? ? Guy Brandenburg, Washington, DC? guysmathastro.wordpress.com
http://gfbrandenburg.wordpress.com/
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
============================
|
Re: First sputter deposition efforts
Andrew, this is great news and hopefully it will help me get up more enthusiasm. But time is a problem. As to reversing the wires - well it worked as it was supposed to do. And the cathode will be connected to the negative (-) wire so it makes sense to me. The + gas ions were attracted to the mangets, hit the AL and heated it. Perhaps a much thicker piece of metal such as a thick disk will melt or evaporate more evenly. This is more like the commercial targets. I really want to deposit Cr for this application of mine. And I want it to stick really really well and thought it just may be worth a trial of sputtering. Hence the interest. Which increased when I found out that the magnetrons, which sounded complicated, were a lot simpler than I had expected when I researched it. I have not seen videos - only pictures and theoretical stuff. But it seems almost too simple to work. I note in most real world applications , they use water cooling and it seems from your experiments that it will be needed. Again from what I have read, there is a plasma pattern and voltage which is far more effective at sputtering. Maybe with a magnetron this is less critical because the pattern goes around in an endless ring. The real issue with evaporative coaters is a much higher clean vacuum. If this can be got to work well it means a diff or turbo pump will not be needed. But I find it hard to accept that at the milder vacuum pressure where the Plasma is working, the mean free path is long enough for the metal ions do travel and deposit as a perfect shiny film. Have to run. Peter. Peter,
I have been meaning to try something very similar but just keep running
out
of time.
Are the magnets coupled by a magnetic path such as iron underneath ?
I saw that in the youtube videos also but my setup did not allow for it so
I did not do it. The round magnet is about 3/4" thick and the N35 magnet
is about 1/4" thick so I could not really put a bar behind them. I did
stack up 2 of the N35 magnets so that made them stronger ( I presume ) but
a single one was already far stronger than the round magnet so I doubt it
made a difference.
The big issue was the polarity of the leads going to the various parts of
the assembly. At first I attached what indicated to be the (+) lead to the
magnet and target alumum foil. I dangled what indicated to be the (-) lead
above the magnets a few millimeters. At 600 vdc the copper wire that
indicated (-) began to glow red and promptly melted. No aluminum foil
sputtering was going on anywhere. There was a really cool green plasma
flowing in the test chamber but only till the copper wire melted. Do you
know how hot you have to get copper to melt it ! ! ! ! !
So I swapped the leads on the magnets. I know the magnets are supposed to
be cathodes and that means (+) but I don't understand electricity and it
hates me so I figured why not try. I put the lead that indicates (-) on
the magnet and dangled the (+) lead above the the assembly and at 450 VDC
the plasma lit up and that ring of magic happened and sputtering of
aluminum commenced. This time the magnets got hot and the wire did not.
So once again I have no idea what direction electrons fly or crawl or
teleport but if you cant make sputtering happen with the leads one way,
then try the other way.
Did you check if Al was being deposited ?
No. This was a test to see if the concept worked at all. The aluminum
left the surface of the aluminum foil so it went somewhere. I will see if
I cant put a microscope glass slide in there today and deposit some
aluminum onto it.
I did discover that the rate of erosion went up dramatically when I turned
off the little vacuum pump. There was still vacuum in the little can but
the overall pressure went up a bit. That made the plasma very angry. I am
guessing it is like back filling with a bit of argon ( putting in some gas
that can be ionized ) as the instructions say to do. I will try that with
the big chamber as my little can really is not set up for this kind of
stuff. It keeps shorting across the inputs as they are only a few inches
apart.
Oh I used a few layers of aluminum foil as the start up sometimes blast
holes in the foil. With three layers the plasma arcs dont make it to the
magnet.
Why choose Al for sputter testing. It is supposedly very slow to sputter
so
something else should work a lot better ?
Because you cant get copper foil at Piggly Wiggly :_)))))) I swiped some
aluminum foil from the wife and used it to protect the magnets. If she had
copper foil then I would have tried that. My guess as to why aluminum
sputters slower is that the heat created by the plasma is dissipated very
quickly into the aluminum mass. As the aluminum targets are tied to the
magnets and the magnets are cooled my guess is that the aluminum target is
cooled and a lot of the heat that would be going into making aluminum gas
is being drawn off by the heat flow characteristics of the metal itself.
But that is just a guess.
I did notice on the eroded aluminum foil that there are dozens of tiny
little balls of aluminum all over the eroded patches. My guess is that the
aluminum was liquifying on the surface of the aluminum foil and surface
tension was pulling it into a ball before evaporation eroded the ball.
Again, just a guess. But there are no aluminum balls on the shiny parts of
the foil.
I seem to remember that you have an evaporative Al setup so this seems
unnecessary for Al coated mirrors.
Yes I do. I have 9 sets of 4 tungsten coils arranged on a 48" inch circle
( with one in the center ). I can vaporize all the aluminum I want as long
as I put in 100 amps at 12 vac into 4 of the coils in series. That works,
but I have run the 9 sets in series and only coat a section of the mirror
at a time. If it all works great then I get realy good coatings and they
stick down good. But if only one set of coils is unhappy for any reason, I
get a bad coating. So I want to switch to plasma deposition like the big
boys use.
I am building a rotary system that will allow me to rotate the whole 65"
dia mirror holder on the door of the chamber so that the mirrors rotate in
front of the plasma discharge bar ( yet to be built ). That way the plasma
sputter bar can be a few inches away from the mirror and the sputtering
will have the best chance of sticking to the mirrors. Again, this is how
the big boys do it. I just have my mirrors mounted on a vertical wall so
all my stuff has to flow horizontally. The big boys suspend their mirrors
above the rotating plasma sputter bar or suspend the rotating plasma
sputter bar above the mirror. Either way it is a long bar that covers the
radius of the mirror and the coating is done by rotating the bar till it
covers the whole mirror.
Hummmmmm now that I think of that, I wonder how they account for the
change in angular velocity and the different rates at which square inches
of uncoated glass is passing under the sputter bar. There must be more
sputtering going on as you go outward on the radius to make up for the
increasing amount of glass you have to coat. Or the sputter section would
have to be pie wedge shaped in some way. Do you have any idea how they do
this.
I will post my successes and failures as I learn how to do this. I am
hoping I can build a bunch of cheap small plasma coaters and just line them
up in a row for my spray bar. I dont see why this will not work but I am
sure there is a reason that I just dont know.
I have two Hign Vact setups. One will deposit (evaporate) Al on a mirror
surface but the vacuum is not clean enough for good adhesion.
I had thiughtg of revamping this to sputtering hoping the plasma will
glean
as well and promote better adhesion. And a magnetron setup seems a good
way
to speed things up.
So I now have this oilless setup which I want to experiment with as well.
Unfortunately, while I have partly built a chamber with leadins etc it is
not finished and I am very bust with other work at the moment. Some of
what I want to do is quite small.
Please post anything else you do and hopefully in a few weeks I may have
something of my own to add.
Peter Smith
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|
Re: First sputter deposition efforts
|
Re: First sputter deposition efforts
Andrew Aurigema eosraptor@... [VacuumX] wrote I believe I have eroded aluminum with plasma. The once shiny aluminum foil
is now dull and pitted and missing in some places after 2 minutes of purple
plasma.
A bud tore apart a microwave oven and rigged me up a high voltage DC supply
fed by a variac. With about 40 vac input to the microwave oven
transformer, the output is about 450 vdc. The little roughing pump is
pulling down to about 5 torr and the electrodes are about 10mm apart.
The magnetron I ginned up is just the circular magnet from the transformer
with a little N35 ( super magnet ) held at its center with an aluminum
plug. I covered the magnets with aluminum foil and put the whole assembly
on a plastic stand in the little degassing chamber. The magnet gets hot
quick so test runs are less than 3 minutes.
This is a long way from making telescope mirrors reflective but it is a
start. I have been meaning to try something very similar but just keep running out of time. Are the magnets coupled by a magnetic path such as iron underneath ? Did you check if Al was being deposited ? Why choose Al for sputter testing. It is supposedly very slow to sputter so something else should work a lot better ? I seem to remember that you have an evaporative Al setup so this seems unnecessary for Al coated mirrors. I have two Hign Vact setups. One will deposit (evaporate) Al on a mirror surface but the vacuum is not clean enough for good adhesion. I had thiughtg of revamping this to sputtering hoping the plasma will glean as well and promote better adhesion. And a magnetron setup seems a good way to speed things up. So I now have this oilless setup which I want to experiment with as well. Unfortunately, while I have partly built a chamber with leadins etc it is not finished and I am very bust with other work at the moment. Some of what I want to do is quite small. Please post anything else you do and hopefully in a few weeks I may have something of my own to add. Peter Smith --- This email is free from viruses and malware because avast! Antivirus protection is active.
|
First sputter deposition efforts
I believe I have eroded aluminum with plasma.? The once shiny aluminum foil is now dull and pitted and missing in some places after 2 minutes of purple plasma. ? A bud tore apart a microwave oven and rigged me up a high voltage DC supply fed by a variac.? With about 40 vac input to the microwave oven transformer, the output is about 450 vdc.? The little roughing pump is pulling down to about 5 torr and the electrodes are about 10mm apart. ?
The magnetron I ginned up is just the circular magnet from the transformer with a little N35 ( super magnet ) held at its center with an aluminum plug.? I covered the magnets with aluminum foil and put the whole assembly on a plastic stand in the little degassing chamber.? The magnet gets hot quick so test runs are less than 3 minutes. ?
This is a long way from making telescope mirrors reflective but it is a start. ?
Drew in sunny Florida
|
Re: 36" Square Vacuum Chamber
If like me you would be shocked by the asking price of a vacuum vessel of a given volume, you might want to consider the virtues of a stainless pressure vessel rated say 10+ atmospheres, given that external compressive loads are more difficult to resist than internal pressure.
Brian Whatcott
toggle quoted message
Show quoted text
On 11/7/2014 5:46 PM, Peter peter@... [VacuumX] wrote: Hi,
Does anyone know where I can get a large chamber like this? Is there anyone who makes such a device for a reasonable price?
Regards,
Peter
------------------------------------
Posted by: Peter <peter@...>
------------------------------------
------------------------------------
Yahoo Groups Links
|
Re: 36" Square Vacuum Chamber
Bentley's Auction in Albuquerque sold a Dual Beam Sputtering system a couple of months ago for about $16k.? I saw it in the warehouse, looked like around 30"+ inside diameter by maybe 4' long, both ends opened up,? They said some feller in FL bought it.? Can't imagine the shipping on that one.
On Fri, Nov 7, 2014 at 8:05 PM, Andrew Aurigema eosraptor@... [VacuumX] <VacuumX@...> wrote:
?
If you mean new, 36" wide by 36" tall by 36" deep and made of stainless then you are looking at around 20 grand of custom build.? Vacuum and large flat surfaces are not compatible so you may want to think about how big a cylinder you need.? Figure another 20 grand for the rough pump, diff pump, backing pump, valves, gates, intercooler and some way to tell what the vacuum level is. ?
Scrounging off Ebay may score you something close but it will never be exactly what you need and you may have to get very resourceful to make it work.?What are you doing with the chamber ??? ? It makes a huge difference as to what it going to cost you to get there.?? ?
I was looking for a 36" dia by 36" deep chamber when I came across my 68" dia x 68" deep chamber on Ebay.? It was old, trashed by a fire, carbon steel, full of scrap metal and dead animal parts and did I mention trashed by a fire ......... but it was 1/20 the price of a new one that big.? Buying used everything off Ebay I still managed to dump the price of a new car into the project to be able to coat a telescope mirror.
?
?
-- Nick A
"You know what I wish?? I wish that all the scum of the world had but a single throat, and I had my hands about it..."? Rorschach, 1975
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."- Benjamin Franklin, Historical Review of Pennsylvania, 1759
"Suburbia is where the developer bulldozes out the trees, then names the streets after them." Bill Vaughan
"The price of apathy towards public affairs is to be ruled by evil men." Plato
|
Re: 36" Square Vacuum Chamber
If you mean new, 36" wide by 36" tall by 36" deep and made of stainless then you are looking at around 20 grand of custom build.? Vacuum and large flat surfaces are not compatible so you may want to think about how big a cylinder you need.? Figure another 20 grand for the rough pump, diff pump, backing pump, valves, gates, intercooler and some way to tell what the vacuum level is. ?
Scrounging off Ebay may score you something close but it will never be exactly what you need and you may have to get very resourceful to make it work.?What are you doing with the chamber ??? ? It makes a huge difference as to what it going to cost you to get there.?? ?
I was looking for a 36" dia by 36" deep chamber when I came across my 68" dia x 68" deep chamber on Ebay.? It was old, trashed by a fire, carbon steel, full of scrap metal and dead animal parts and did I mention trashed by a fire ......... but it was 1/20 the price of a new one that big.? Buying used everything off Ebay I still managed to dump the price of a new car into the project to be able to coat a telescope mirror.
?
?
On Fri, Nov 7, 2014 at 6:46 PM, Peter peter@... [VacuumX] <VacuumX@...> wrote:
?
Hi,
Does anyone know where I can get a large chamber like this? Is there anyone who makes such a device for a reasonable price?
Regards,
Peter
|
36" Square Vacuum Chamber
Hi,
Does anyone know where I can get a large chamber like this? Is there anyone who makes such a device for a reasonable price?
Regards,
Peter
|
Re: Magnetron sputter system
Also, adding softer metals between joining copper surfaces could help keeping the resistance down. Perhaps even help eliminating voids that trap gasses and other contaminants. I suppose tin or indium would do the job.
I worked on an old sputtering machine that used indium to cold weld the sputtering metal to the heat sink to transfer the current and avoid using holders/fasteners.
These materials possibly need to be line of sight shielded to keep them from messing up the target surfaces.
Best of luck //Daniel from Sweden
|
Re: Magnetron sputter system
?ARRRRRGGGGGGGGG ?this electrical stuff makes no sense.? Copper is from like back in the Jurassic period and is good...... stainless steel is from the space age and is bad. ? ?
My reading has brought me to realize that stainless steel is a serious "no no" in high current flow efforts.? I now have a 14 item list of things to replace in my system so that I can increase the current flow to the tungsten coils and tantalum box heater.?
I have not given up on magnetron sputtering but I have a far better chance of making gaseous silicon monoxide with the tantalum boat heater than with a ( yet to be designed or built ) magnetron sputtering system.? So while I explore the unknowns of HV magnetron plasma deposition offline in a small vacuum chamber, I will be trying to make the little tantalum box glow white hot in the big chamber.? My vintage 1970's thin film measurement and process controller can run either concept once I figure out how to get it working. ?
Now that I know mister copper is my friend, what could possibly go wrong :_))))))))))) ?
Drew in sunny Florida
On Wed, Nov 5, 2014 at 3:42 PM, Andrew Aurigema <eosraptor@...> wrote: Well I looked up the specs for the tantalum box and it is 257 amps at 1.4 volts requiring 360 watts.? I have 12 vac at 500 amps available so I presume I have enough power.?
I also looked up the current carrying capacity of the 3/8" dia steel threaded rods that make up the pass thru's.? It was very much less than it needed to be.? So I will be changing out the two 3/8" steel rods for two 1/2" copper rods and between the two parallel pass thru's I should have a true 500 amps rated capability.? I am also stepping up to 4 each power feeds leading to the tantalum box and 4 each leads going to chamber ground.? Each lead should be 90 amps so that is 360 amps of capability leading to and exiting away from the box. ?
The main feeds to the pass thru's are 3/4" copper stranded cable so that is 500 amp plus. ?
Along with cleaning up all contacts and eliminating all stainless steel conductors in the system I think the next time I power the system up it will glow white hot only where it is supposed to and not along the path. ?
This electricity stuff is nearly as tricky as vacuum. ? ? ??
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Re: Magnetron sputter system
On 11/05/2014 03:42 PM, Andrew Aurigema eosraptor@... [VacuumX] wrote: Well I looked up the specs for the tantalum box and it is 257 amps at
1.4 volts requiring 360 watts. I have 12 vac at 500 amps available so I
presume I have enough power.
I also looked up the current carrying capacity of the 3/8" dia steel
threaded rods that make up the pass thru's. It was very much less than
it needed to be. So I will be changing out the two 3/8" steel rods for
two 1/2" copper rods and between the two parallel pass thru's I should
have a true 500 amps rated capability. I am also stepping up to 4 each
power feeds leading to the tantalum box and 4 each leads going to
chamber ground. Each lead should be 90 amps so that is 360 amps of
capability leading to and exiting away from the box.
The main feeds to the pass thru's are 3/4" copper stranded cable so that
is 500 amp plus.
Along with cleaning up all contacts and eliminating all stainless steel
conductors in the system I think the next time I power the system up it
will glow white hot only where it is supposed to and not along the path. That just blows my mind. My latest commercial board design went to small-volume production not long ago, ~3500 units. A microcontroller, some analog signal conditioning stuff, an RF transceiver, etc. That big power supply you're working with could power all of them. ALL of them. At the same time. ;) Caig DeOxit is the de-facto standard in the electrical metrology field for getting rid of copper oxides in precision circuitry. I don't know if it's appropriate for use at those temperatures, but it might be worth looking into. Next...I have six very large low-voltage DC switching power supplies, three each of two types, originally for a large datacenter-style disk array. They output, if memory serves, 12V and 5V, at somewhere in the three-digits'-worth of amps. They are relatively compact rack-mount units with big beefy bolts for output terminals, and are in excellent condition. I mention this because I'll be driving down to Florida in a few days, and could bring them down with me if you think you might want them. I wouldn't turn down cash, but my primary goal is to get them out of here and into the hands of someone who might use them, and it sounds like you just might! ;) I can get more specific voltage/current specs if you're interested; let me know. This electricity stuff is nearly as tricky as vacuum. Being an electronics guy, that's what I say about vacuum! ;) -Dave -- Dave McGuire, AK4HZ/3 New Kensington, PA
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Re: Magnetron sputter system
Well I looked up the specs for the tantalum box and it is 257 amps at 1.4 volts requiring 360 watts.? I have 12 vac at 500 amps available so I presume I have enough power.?
I also looked up the current carrying capacity of the 3/8" dia steel threaded rods that make up the pass thru's.? It was very much less than it needed to be.? So I will be changing out the two 3/8" steel rods for two 1/2" copper rods and between the two parallel pass thru's I should have a true 500 amps rated capability.? I am also stepping up to 4 each power feeds leading to the tantalum box and 4 each leads going to chamber ground.? Each lead should be 90 amps so that is 360 amps of capability leading to and exiting away from the box. ?
The main feeds to the pass thru's are 3/4" copper stranded cable so that is 500 amp plus. ?
Along with cleaning up all contacts and eliminating all stainless steel conductors in the system I think the next time I power the system up it will glow white hot only where it is supposed to and not along the path. ?
This electricity stuff is nearly as tricky as vacuum. ? ? ??
On Thu, Oct 30, 2014 at 5:19 PM, Lindsay Wilson lindsay@... [VacuumX] <VacuumX@...> wrote:
?
Hi,
Lurker here ;-)
The only advice I could suggest - I think that when you get into
the 1000A range, you really need to go with water-cooled
feedthroughs.
Lesker, for example, have a 400A non-cooled feedthrough, but their
1000A feedthrough is water-cooled. Page here:
I've forgotten much of what I ever knew about thermal coating, but
is it possible to use a wire basket heater instead of the boat? Or
is
the silicon dioxide in powder form and would fall through?
Best regards,
Lindsay
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Ok, I don't do this often, but I know where there is a complete electron microscope up for grabs, shipping for me would be a killer, but for any of our European members this might be do-able.... It's in the UK, ex-RAF. Would need a good clean and refurb (my friend runs a salvage yard), but he is trying to keep it as clean as he can.
Cheers, Thomas.
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Christopher Erickson
Kirk Wallace
Nick Andrews
Daniel Ekman SA2KNG
Dave McGuire