Re: Thermocouple gauge

#3856

Looks like you got a toy to play with; seems like toys can be found on Ebay for cheap. At least you got a very good laboratory vacuum pump for cheap. I don't know enough about them to know what I would be buying; but as I understand it you don't have to worry about back streaming from it. As for me I have purchased diffusion pumps for very cheap; but without any baffle. So far baffles on Ebay are too expensive; hence I am considering making something that will reduce back streaming.

Show quoted text

From: Thomas
To: VacuumX@...
Sent: Wednesday, February 20, 2013 5:12 PM
Subject: [VacuumX] Re: Thermocouple gauge

Vaughn:

Can't answer your question as well a most of the guys in this group.
Just wanted to say that I too grew up on C.L. Stong and 60's era Vacuum.
I recently purchased on Ebay a good Turbo Pump and controller for a crazy low price. I thought I might have to at least replace the bearings, but, it revs up just fine.

Tom M.

--- In VacuumX@..., "Vaughn Mcdowell" wrote:
>
> I am a baby boomer retired in my late 60's. When I was in high school I was experimenting with refrigerator rotary pumps as described by Strong in the Amateur Scientist articles. As a senior in high school I learned to blow Pyrex glass; during college in undergraduate and graduate I worked with vacuums systems but mostly for building Argon ion and N2 lasers. I did some diffusion pump work but very briefly. I remember using gum rubber tubing, stop cock valves, and Pyrex glass tube connections. Afterward I haven't touched vacuum systems until 2003 ( fired up my diffusion pump) but very briefly; and recently much more. I have always had a love for vacuum systems. But my vacuum world has changed significantly with quick disconnect etc. I feel like Rip Van.. Having limited funding I looked to Ebay for getting components that I could afford. I have been slowly acquiring KF fittings for future use. In the meantime I am using what I know to get by with. "Procedures in Experimental Physics " Strong has been my Bible. I have acquired more recent Varian training manuals; info from Bell Jar; etc.
>
> When I was in College McLeod gauges were used for reference; now I have very limited vacuum references; the gas discharge method; the TC gauge and Ion gauge method. The first method is very dangerous in the 10 micron and below: http://vaughns_page.50webs.com/vacuum/gas_discharge1/X-ray1/x-ray_gas_tube1.html
>
> I have abandoned this method; in the future I have some high voltage experiments in mind: http://vaughns_page.50webs.com/vacuum/magnetron/9Jan13Exp/9jan13Exp.pdf .
>
> The TC gauge is limited but I am mainly interested in some ball park idea; I have purchased several DV-6M types new and used; I can used the hysteresis factory data to get some reference but how do I know if is new that some oil back streaming hasn't changed or shifted the thermodynamic continuity flow equilibrium much less the non linear characteristics? When I started testing my diffusion pumps the TC controller would quickly peg below zero; I started zeroing my TC controllers using the diffusion pumps. At the moment I feel like I am working in the dark. Even if I were to use a calibrated TC gauge; how do I know mechanical and diffusion pump back streaming won't significantly affect its thermodynamics significantly??
>
> Thanks
>

Re: Thermocouple gauge

#3855

开云体育

Thomas wrote:

?

Vaughn:

Can't answer your question as well a most of the guys in this group.
Just wanted to say that I too grew up on C.L. Stong and 60's era Vacuum.

??? Me too.? I still have some stuff I bought from Frank Lee including a couple of the little single-stage oil pumps, one unused.? I've had a lot of fun with them.

I recently purchased on Ebay a good Turbo Pump and controller for a crazy low price. I thought I might have to at least replace the bearings, but, it revs up just fine.

Tom M.

Ed

--- In VacuumX@..., "Vaughn Mcdowell" wrote:
>
> I am a baby boomer retired in my late 60's. When I was in high school I was experimenting with refrigerator rotary pumps as described by Strong in the Amateur Scientist articles. As a senior in high school I learned to blow Pyrex glass; during college in undergraduate and graduate I worked with vacuums systems but mostly for building Argon ion and N2 lasers. I did some diffusion pump work but very briefly. I remember using gum rubber tubing, stop cock valves, and Pyrex glass tube connections. Afterward I haven't touched vacuum systems until 2003 ( fired up my diffusion pump) but very briefly; and recently much more. I have always had a love for vacuum systems. But my vacuum world has changed significantly with quick disconnect etc. I feel like Rip Van.. Having limited funding I looked to Ebay for getting components that I could afford. I have been slowly acquiring KF fittings for future use. In the meantime I am using what I know to get by with. "Procedures in Experimental Physics " Strong has been my Bible. I have acquired more recent Varian training manuals; info from Bell Jar; etc.
>
> When I was in College McLeod gauges were used for reference; now I have very limited vacuum references; the gas discharge method; the TC gauge and Ion gauge method. The first method is very dangerous in the 10 micron and below:
>
> I have abandoned this method; in the future I have some high voltage experiments in mind: .
>
> The TC gauge is limited but I am mainly interested in some ball park idea; I have purchased several DV-6M types new and used; I can used the hysteresis factory data to get some reference but how do I know if is new that some oil back streaming hasn't changed or shifted the thermodynamic continuity flow equilibrium much less the non linear characteristics? When I started testing my diffusion pumps the TC controller would quickly peg below zero; I started zeroing my TC controllers using the diffusion pumps. At the moment I feel like I am working in the dark. Even if I were to use a calibrated TC gauge; how do I know mechanical and diffusion pump back streaming won't significantly affect its thermodynamics significantly??
>
> Thanks
>

Re: Thermocouple gauge

#3854

Vaughn:

Can't answer your question as well a most of the guys in this group.
Just wanted to say that I too grew up on C.L. Stong and 60's era Vacuum.
I recently purchased on Ebay a good Turbo Pump and controller for a crazy low price. I thought I might have to at least replace the bearings, but, it revs up just fine.

Tom M.

Show quoted text

--- In VacuumX@..., "Vaughn Mcdowell" <vaughn.mcdowell@...> wrote:

I am a baby boomer retired in my late 60's. When I was in high school I was experimenting with refrigerator rotary pumps as described by Strong in the Amateur Scientist articles. As a senior in high school I learned to blow Pyrex glass; during college in undergraduate and graduate I worked with vacuums systems but mostly for building Argon ion and N2 lasers. I did some diffusion pump work but very briefly. I remember using gum rubber tubing, stop cock valves, and Pyrex glass tube connections. Afterward I haven't touched vacuum systems until 2003 ( fired up my diffusion pump) but very briefly; and recently much more. I have always had a love for vacuum systems. But my vacuum world has changed significantly with quick disconnect etc. I feel like Rip Van.. Having limited funding I looked to Ebay for getting components that I could afford. I have been slowly acquiring KF fittings for future use. In the meantime I am using what I know to get by with. "Procedures in Experimental Physics " Strong has been my Bible. I have acquired more recent Varian training manuals; info from Bell Jar; etc.

When I was in College McLeod gauges were used for reference; now I have very limited vacuum references; the gas discharge  method; the TC gauge and Ion gauge method. The first method is very dangerous in the 10 micron and below: 

I have abandoned this method; in the future I have some high voltage experiments in mind:  .

The TC gauge is limited but I am mainly interested in some ball park idea; I have purchased several DV-6M types new and used; I can used the hysteresis factory data to get some reference but how do I know if is new that some oil back streaming hasn't changed or shifted the thermodynamic continuity flow equilibrium much less the non linear characteristics? When I started testing my diffusion pumps the TC controller would quickly peg below zero; I started zeroing my TC controllers using the diffusion pumps. At the moment I feel like I am working in the dark. Even if I were to use a calibrated TC gauge; how do I know mechanical and diffusion pump back streaming won't significantly affect its thermodynamics significantly??

Thanks

Re: Vacuum

#3853

开云体育

We get normally get good results after plasma cleaning if we get anything below 1.0e-4 Torr. We coat a few mirrors a month. This time we could not get below 1.7e-4 torr.

Guy

Show quoted text

On Feb 17, 2013, at 18:23, Vladimir Chutko <chutko@...> wrote:

?

Guy,

Al coating performance strongly depends on vacuum and deposition rate.
In general, it is recommended to evaporate Al on a cold substrate at
pressures at least below 2x10-5 torr with deposition rate at least 10
A/s. Othervice the growing coating will trap air molecules, adhesion and
mechanical properties will be not good, and you won't be able to obtain
really high reflectance. The substrate pre-cleaning with an ion beam or
glow discharge is also needed.

Regards,

Vladimir Chutko

On 2/12/2013 6:55 PM, Guy Brandenburg wrote:
>> Just tried and failed to aluminize a mirror because the pressure would not go below 1.7x10^-4 torr; as a result the coating was semi transparent. If it goes below 1.0e-4 all is good. This is unusual. Persisted even when i tightened stuff up.
>> Any suggestions?
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

Re: Vacuum

#3852

Guy,

Al coating performance strongly depends on vacuum and deposition rate. In general, it is recommended to evaporate Al on a cold substrate at pressures at least below 2x10-5 torr with deposition rate at least 10 A/s. Othervice the growing coating will trap air molecules, adhesion and mechanical properties will be not good, and you won't be able to obtain really high reflectance. The substrate pre-cleaning with an ion beam or glow discharge is also needed.

Regards,

Vladimir Chutko

Show quoted text

On 2/12/2013 6:55 PM, Guy Brandenburg wrote:
Just tried and failed to aluminize a mirror because the pressure would not go below 1.7x10^-4 torr; as a result the coating was semi transparent. If it goes below 1.0e-4 all is good. This is unusual. Persisted even when i tightened stuff up.
Any suggestions?------------------------------------

Yahoo! Groups Links

Re: Veeco EP 2A 1 DP backed by 1402

#3851

开云体育

Thanks for sharing Vaughn, nice setup. I'm also learning and gathering equipment. I have a gauge controller that I can't find any information about and will have to reverse engineer it to use. Can you give me the links to the manual and schematics for your controller (or email it to me) as it will help me understand mine a bit better please.
I look forward to seeing your progress.

Don Black.

On 18-Feb-13 5:44 AM, Vaughn Mcdowell wrote:

Show quoted text

?

I decided to test my Veeco diffusion pump using the 1402 that I have just refurbished. At the present I am using my Web site for documenting my experiments, which I don't mind sharing; it is very convenient for me; decided to share photos of my experimental setup.

The following link shows a photo of the 1402 backing the DP:

I don't have yet any 2" vacuum pluming; attached to the top is a quick adapter for the TC and ion gauge tube to sample the pressure. I plan to have something more suitable in the future. The ion gauge should be rotated 90 degrees; the tungsten heater is drooping slightly which I understand affects its sensitivity value.

The next link shows the TC gauge that was zeroed after the DP reached 0.1 micron.

The next link shows the CVC ion gauge controller;

The emission current is 1 ma. corresponding to slightly higher than 0.02 micron reading. At 10 ma. the pressure settles to about 0.06 micron; as expected higher than that at 1 ma. I believe this is due to enhanced electron space charge cloud.

I got two of these for very cheap; I wanted something very basic to learn from; I was able to fine the manual with schematics on the Web; before using, the emission current and electrometer were checked ( using my DVMs) for calibration. I was very surprised after so many years how close to calibration they were.

The last link shows the DP that I modified for the cooling fan I found in my junk box:

Having no information regarding this DP; I decided to try using about 70 cc of the Specialty Fluid 704 equivalent ( at the time it was the cheapest that I could find); The Variac, for the heater, was finally set to 100 VAC corresponding to the above results; don't know for the this fluid type what the optimum Variac setting should be.

Regarding the ion gauge reading ( 1 ma. emission) assuming the typical sensitivity value given for ( N2 or air). I do know that I started with air; however what I don't know is what the ion gauge is ionizing ( out gas ; back streaming etc); Out gassing in the ion gauge itself; I didn't do much degassing yet. I don't know typically how close to the typical sensitivity value given should be trusted. I am a novice getting my feet wet just learning how to drive. My goal is to eventually get down near 10-6 Torr someday for electron beam experiments that I have in mind.

Veeco EP 2A 1 DP backed by 1402

#3850

I decided to test my Veeco diffusion pump using the 1402 that I have just refurbished. At the present I am using my Web site for documenting my experiments, which I don't mind sharing; it is very convenient for me; decided to share photos of my experimental setup.

The following link shows a photo of the 1402 backing the DP: 

I don't have yet any 2" vacuum pluming; attached to the top is a quick adapter for the TC and ion gauge tube to sample the pressure. I plan to have something more suitable in the future. The ion gauge should be rotated 90 degrees; the tungsten heater is drooping slightly which I understand affects its sensitivity value.

The next link shows the TC gauge that was zeroed after the DP reached 0.1 micron.

The next link shows the CVC ion gauge controller; 

The emission current is 1 ma. corresponding to slightly higher than 0.02 micron reading. At 10 ma. the pressure settles to about 0.06 micron; as expected higher than that at 1 ma. I believe this is due to enhanced electron space charge cloud.

 I got two of these for very cheap; I wanted something very basic to learn from; I was able to fine the manual with schematics on the Web; before using, the emission current and electrometer were checked ( using my DVMs) for calibration. I was very surprised after so many years how close to calibration they were.

The last link shows the DP that I modified for the cooling fan I found in my junk box:   

Having no information regarding this DP; I decided to try using about 70 cc of the Specialty Fluid 704 equivalent ( at the time it was the cheapest that I could find); The Variac, for the heater, was finally set to 100 VAC corresponding to the above results; don't know for the this fluid type what the optimum Variac setting should be.

Regarding the ion gauge reading ( 1 ma. emission) assuming the typical sensitivity value given for ( N2 or air). I do know that I started with air; however what I don't know is what the ion gauge is ionizing ( out gas ; back streaming etc); Out gassing in the ion gauge itself; I didn't do much degassing yet. I don't know typically how close to the typical sensitivity value given should be trusted. I am a novice getting my feet wet just learning how to drive. My goal is to eventually get down near 10-6 Torr someday for electron beam  experiments that I have in mind.

Thermocouple gauge

#3849

I am a baby boomer retired in my late 60's. When I was in high school I was experimenting with refrigerator rotary pumps as described by Strong in the Amateur Scientist articles. As a senior in high school I learned to blow Pyrex glass; during college in undergraduate and graduate I worked with vacuums systems but mostly for building Argon ion and N2 lasers. I did some diffusion pump work but very briefly. I remember using gum rubber tubing, stop cock valves, and Pyrex glass tube connections. Afterward I haven't touched vacuum systems until 2003 ( fired up my diffusion pump) but very briefly; and recently much more. I have always had a love for vacuum systems. But my vacuum world has changed significantly with quick disconnect etc. I feel like Rip Van.. Having limited funding I looked to Ebay for getting components that I could afford. I have been slowly acquiring KF fittings for future use. In the meantime I am using what I know to get by with. "Procedures in Experimental Physics " Strong has been my Bible. I have acquired more recent Varian training manuals; info from Bell Jar; etc.

When I was in College McLeod gauges were used for reference; now I have very limited vacuum references; the gas discharge  method; the TC gauge and Ion gauge method. The first method is very dangerous in the 10 micron and below: 

I have abandoned this method; in the future I have some high voltage experiments in mind:  .

The TC gauge is limited but I am mainly interested in some ball park idea; I have purchased several DV-6M types new and used; I can used the hysteresis factory data to get some reference but how do I know if is new that some oil back streaming hasn't changed or shifted the thermodynamic continuity flow equilibrium much less the non linear characteristics? When I started testing my diffusion pumps the TC controller would quickly peg below zero; I started zeroing my TC controllers using the diffusion pumps. At the moment I feel like I am working in the dark. Even if I were to use a calibrated TC gauge; how do I know mechanical and diffusion pump back streaming won't significantly affect its thermodynamics significantly??

Thanks

Re: Tri Clover Fittings

#3847

开云体育

Howdy,

The first issue I foresee is the o-ring material. If the seals are
standard O-rings, great, then you can just order Viton O-rings. But I
thought those fittings used custom seals with odd cross-sections.

Sigh...you're right. Here's a high-res photo of some gaskets:

They look mainly flat, with a ridged part around them, and the flanges have an O-ring
groove in them. I suppose the advantage of that is you don't need a centering ring
like with KF flanges.

You can get Buna-N (nitrile) gaskets easily, and fortunately some sites (found one EBay
store ) sell Viton gaskets.

Another possibility to think about is that they don't have to be
absolutely gas-tight for dairy operations, small leaks may be permitted.

Could be, although I would've thought that for hygienic reasons they'd
ensure there's no places where stuff could get trapped or porosity.

Another thing to think about: for the most part, high vacuum fittings
are designed such that when assembled together, very little "trapped"
volume remains in the conjoined system, that is, space that is
connected to the pumped volume, but has low conductance, IOW, "nooks
and crannies".

The large flat gaskets might give rise to this.

But I agree that these do resemble KFs an awful lot, and I'm going to
start comparing prices out of curiosity - if they are drastically
cheaper than what I can get from Duniway et al, then an experimental
purchase and test would seem in order!

Would be very interested to hear how it goes! It turns out I can get them in the UK,
just searching under "tri clamp fitting" instead.

On a related hardware topic, have you ever come across the convoluted metal
hose used for domestic gas main installations? Stuff like this -

Maybe things are different in the US, but there's always a bit of that stuff used between
the gas main and house regulator. It looks to be very nice for vacuum use - not quite
as flexible as proper vacuum bellows tubing, but still pretty good. Also see ebay for
"flexible exhaust" - for example item 230830064598. Again, bellows tubing just like
that used for vacuum. No ends unfortunately!

Cheers,

Lindsay

- Bill "Gomez" Lemieux,
The Highland Tinker

Re: Tri Clover Fittings

#3848

开云体育

Please keep us informed of what you find, they do seem a fraction of the price of "proper" vacuum fittings. You make good points about trapped volume leaks and seals though. Hope they work out. The maximum temperature of "rubber" seals, O-rings, etc. is important for baking out too.

Don Black.

On 16-Feb-13 3:26 AM, Gomez Addams wrote:

Show quoted text

?

On Feb 15, 2013, at 3:53 AM, imajeenyus42 wrote:

> Howdy,
>
> I've been a lurker here for some time - came across this recently
> and thought it might be interesting/useful.
>
> While looking for some info on brewing, I found these "tri clover
> fittings":
>
>
>
> They seem to be standard in brewing/dairy plant, and look very
> similar to the KF vacuum fittings (genderless flanges, O-ring, and
> clamp). They're polished for hygenic reasons, so I guess would do
> well for vacuum. Most importantly they're dirt cheap!''

The first issue I foresee is the o-ring material. If the seals are
standard O-rings, great, then you can just order Viton O-rings. But I
thought those fittings used custom seals with odd cross-sections.

Another possibility to think about is that they don't have to be
absolutely gas-tight for dairy operations, small leaks may be permitted.

Another thing to think about: for the most part, high vacuum fittings
are designed such that when assembled together, very little "trapped"
volume remains in the conjoined system, that is, space that is
connected to the pumped volume, but has low conductance, IOW, "nooks
and crannies".

But I agree that these do resemble KFs an awful lot, and I'm going to
start comparing prices out of curiosity - if they are drastically
cheaper than what I can get from Duniway et al, then an experimental
purchase and test would seem in order!

- Bill "Gomez" Lemieux,
The Highland Tinker

Re: Welch 1402

#3846

Or thermite when mixed with aluminum powder...also not good for your vac pump!

Show quoted text

On Wed, Feb 13, 2013 at 5:53 PM, Gomez Addams <gomez@...> wrote:

?

A _little_ red rust makes a fine lapping compound for close-fitting
metal parts... just sayin'. ;D

On Feb 12, 2013, at 3:03 PM, Vaughn Mcdowell wrote:

> I got one frozen up too from Ebay which was supposed to have been
> refirbished; resisted taking it apart and realized that it was dry
> ( completely drained of oil and apparently sat on the shelf ). I put
> some oil in it and gently wiggled it ( hopping not to break the vain
> shaft) with some force; but with care. Believe it or not it finally
> gave way no longer frozen. When I flushed it I realized that the
> vanes were slightly rusted to the stator. Amazingly this initially
> frozen Welch 1400 turned out to be one of my best Ebay investments;
> at least if I believe my TC gauge ( less than 2 microns). Maybe you
> can get your frozen pump working.

I feel extraordinarily lucky to have had so few complaints with
roughing pumps.

I lucked into my first one (a Cenco HyVac7) at an electronics surplus
store who despaired
of ever being rid of it. It was _well_ used (ahem) with a leaking
shaft seal, no motor, not even a mounting base, for $50.

It pumped okay, but the rebuild sounded like more than I wanted to
take on, so I wound up giving it to another friend after someone gave
me a Hyvac 14 in good working order. :)

- Bill "Gomez" Lemieux,
The Highland Tinker

--
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: Tri Clover Fittings

Gomez Addams

#3845

On Feb 15, 2013, at 3:53 AM, imajeenyus42 wrote:

Howdy,

I've been a lurker here for some time - came across this recently  and thought it might be interesting/useful.

While looking for some info on brewing, I found these "tri clover  fittings":

They seem to be standard in brewing/dairy plant, and look very  similar to the KF vacuum fittings (genderless flanges, O-ring, and  clamp). They're polished for hygenic reasons, so I guess would do  well for vacuum. Most importantly they're dirt cheap!''The first issue I foresee is the o-ring material.  If the seals are  standard O-rings, great, then you can just order Viton O-rings.  But I  thought those fittings used custom seals with odd cross-sections.

Another possibility to think about is that they don't have to be  absolutely gas-tight for dairy operations, small leaks may be permitted.

Another thing to think about: for the most part, high vacuum fittings  are designed such that when assembled together, very little "trapped"  volume remains in the conjoined system, that is, space that is  connected to the pumped volume, but has low conductance, IOW, "nooks  and crannies".

But I agree that these do resemble KFs an awful lot, and I'm going to  start comparing prices out of curiosity - if they are drastically  cheaper than what I can get from Duniway et al, then an experimental  purchase and test would seem in order!

 - Bill "Gomez" Lemieux,
	The Highland Tinker

Re: Welch 1402

Gomez Addams

#3844

On the gasket where the case parts split - is that RTV?

There's no chance any RTV got inside the pump or any
oil-wetted surfaces is there?

I'm probably stating the obvious, but I don't think you
want an aromatic acid like acetic any where in your
vacuum system, for both obvious reasons.

OTOH, if you've flushed the pump and its backing a DP
well, that would sorta prove the pudding, I suppose. :)

 - G.

On Feb 14, 2013, at 3:25 PM, Vaughn Mcdowell wrote:

Opps my last link should be 

 - Bill "Gomez" Lemieux,
	The Highland Tinker

Tri Clover Fittings

#3843

Howdy,

I've been a lurker here for some time - came across this recently and thought it might be interesting/useful.

While looking for some info on brewing, I found these "tri clover fittings":

They seem to be standard in brewing/dairy plant, and look very similar to the KF vacuum fittings (genderless flanges, O-ring, and clamp). They're polished for hygenic reasons, so I guess would do well for vacuum. Most importantly they're dirt cheap!

Maybe you know about them already, but they're totally new to me (in the UK, where we seem to be behind the times....)

Incidentally, no relation to the "tri laser connector" that Bones used to fix Spock's brain ;-)

Cheers,

Lindsay

Re: Welch 1402

#3842

Opps my last link should be

Re: Welch 1402

#3841

Opps my last link should be http://vaughns_page.50webs.com/vacuum/1402Ebay_2/100_1679b.JPG

Re: Welch 1402

#3840

After I have put new oil in my pump ; it was tested again; it has been partially repainted ; added intake and exhaust? components; decided to give links of my Web showing photos of my new toy and TC gauge measurements. I don't plan to do anything more on it; plan to using it for testing my largest diffusion pump.

The TC gauge reading is shown: http://vaughns_page.50webs.com/vacuum/1402Ebay_2/100_1684b.JPG

When I initially got this gauge from Ebay and tested it with one of my diffusion pumps; the needle pegged well below ? zero very quickly after warming up. After running for some time the controller? was adjusted so that the needle was set to zero. Although the 1402 seems to pump fairly quickly at first; it takes quite a long time for it to reach the value indicated. I am not claiming that the TC value is absolutely correct ; just what it reads after being zeroed with a diffusion pump.

Photos of the 1402 that I refurbished : http://vaughns_page.50webs.com/vacuum/1402Ebay_2/100_1678c.JPG

http://vaughns_page.50webs.com/vacuum/1402Ebay_2/100_1678c.JPG

I am happy with my new toy

Re: Welch 1402

Gomez Addams

#3839

Yeah, you can't use anything even slightly abrasives to remove rust
from any of the bearing/wiping/sliding surfaces such as shafts and
vanes and valve seats and so forth.

If there is pitting or a change in the shape or surface quality of
the cleaned steel, that part is scrap.

On Feb 14, 2013, at 5:22 AM, Russell Shaw wrote:

On 14/02/13 02:36, Vaughn Mcdowell wrote:
...

Regarding freeze up besides rust rotor and stator components  keeping then from
sliding; I should have mentioned when I was working on my 1402; the  components
were somewhat frozen ( hard to rotate the shaft) because the rotor  and stator
were not lined up correctly ( as suggested from the Sam's FAQ) ;  that's why I
assembled it with the bolts loose then rotated the shaft with the  system in oil;
then later tightened the bolts; did not have the alignment paper as  discussed in
the FAQ link; so I assumed this to be the next best thing working  in the dark (
ie limited information found on the Web) . Another incident occured  with a 1400
that I bought for very cheep had the vane rod bent keeping the vane  from sliding
in and out the rotor.For rust-removal, evaporust is good because it dissolves rust  instead of
converting it like other stuff. It works better when warm > 20-25degC.
Complete immersion or continuous spraying with a jet is best.



The 1402 that I recently got on Ebay didn't have exhaust or air  intake
components. With my limited knowledge as to where to get  replacement components;
found out the nipple replacements were outside the beer budget.  After finding
the required thread 1-20 I found
 and
purchased three. With my metal lathe the hole was enlarged to fit a  hose barb
purchased from the hardware store. The intake was assembled using  solder. I then
used the Loctite 592 with Teflon tape; seems to work OK.You could make an oil mist output filter using a car oil or air  filter.


------------------------------------

Yahoo! Groups Links



 - Bill "Gomez" Lemieux,
	The Highland Tinker

Re: Welch 1402

#3838

On 14/02/13 02:36, Vaughn Mcdowell wrote:
...

Regarding freeze up besides rust rotor and stator components keeping then from
sliding; I should have mentioned when I was working on my 1402; the components
were somewhat frozen ( hard to rotate the shaft) because the rotor and stator
were not lined up correctly ( as suggested from the Sam's FAQ) ; that's why I
assembled it with the bolts loose then rotated the shaft with the system in oil;
then later tightened the bolts; did not have the alignment paper as discussed in
the FAQ link; so I assumed this to be the next best thing working in the dark (
ie limited information found on the Web) . Another incident occured with a 1400
that I bought for very cheep had the vane rod bent keeping the vane from sliding
in and out the rotor.For rust-removal, evaporust is good because it dissolves rust instead of converting it like other stuff. It works better when warm > 20-25degC.
Complete immersion or continuous spraying with a jet is best.



The 1402 that I recently got on Ebay didn't have exhaust or air intake
components. With my limited knowledge as to where to get replacement components;
found out the nipple replacements were outside the beer budget. After finding
the required thread 1-20 I found
 and
purchased three. With my metal lathe the hole was enlarged to fit a hose barb
purchased from the hardware store. The intake was assembled using solder. I then
used the Loctite 592 with Teflon tape; seems to work OK.You could make an oil mist output filter using a car oil or air filter.

Re: Welch 1402

Gomez Addams

#3837

I worked for an outfit who bought consumables and hardware from  Duniway on a regular
basis.  Their staff are knowledgeable - at least the ones I spoke to -  and they do
not sell junk, as far as I can tell.

No vacuum vendor will survive long selling lousy stuff, the market is  too small.
Duniway has the best prices I've found anywhere, and I've had no  trouble with
anything I've bought from them for my personal use.

I think I might worry a little bit about dual-use oil, until I know  more about
it.  It seems to me just a little hard to believe that an oil good for  DP operation
will also have sufficient high-pressure lubricity to preserve the  bearing surfaces
in my mechanical backing pump.  I admit to ignorance, but the  requirements for the
two applications are so different - with the exception of possessing  low vapor
pressure when cold, obviously, that it just seems wiser to me to use  what the
manufacturer's recommend: DP oil in the DP, mechanical oil in the  mechanical
pump.

On Feb 13, 2013, at 8:36 AM, Vaughn Mcdowell wrote:

It seems that vacuum pump oil price has gone up recently; for awhile  I have been purchasing , from Specialty Fluids Co.  their type  MVT-20 which is apparently a hydrocarbon dual use ( diffusion and  mechanical). I have had good experience using it. I am considering  their MVT-19 which costs less. I have also started using the INLAND  19 TOP QUALITY HIGH VACUUM PUMP OIL ; its in my opinion  very good .  However I must confess my vacuum experience is very limited; I am in  the learning mode. I am hoping to look into Duniway to see if it is  a better fit to the beer budget.

Regarding the exploded parts diagram for the 1402 pump; item 17  "center plate" is shown to be one component; I can say for my 1402  that the center plate is split into two halves not indicated on the  diagram. Having semi-circular cavities facing each other also not  indicated. I don't know why this is not illustrated.

Regarding freeze up besides rust rotor  and stator components  keeping then from sliding; I should have mentioned when I was  working on my 1402; the components were somewhat frozen ( hard to  rotate the shaft) because the rotor and stator were not lined up  correctly ( as suggested from the Sam's FAQ) ; that's why I  assembled it with the bolts loose then rotated the shaft with the  system in oil; then later tightened the bolts; did  not have the  alignment paper as discussed in the FAQ link; so I assumed this to  be the next best thing working in the dark ( ie limited information  found on the Web) . Another incident occured with a 1400 that I  bought for very cheep had the vane rod bent keeping the vane from  sliding in and out the rotor.

The 1402 that I recently got on Ebay didn't have exhaust or air  intake components. With my limited knowledge as to where to get  replacement components; found out the nipple replacements were  outside the beer budget. After finding the required thread 1-20 I  found and purchased three. With my metal lathe the hole was enlarged to  fit a hose barb purchased from the hardware store. The intake was  assembled using  solder. I then used the Loctite 592 with Teflon  tape; seems to work OK.





 - Bill "Gomez" Lemieux,
	The Highland Tinker