Hello, I have just bought a Welch 1402 second hand which I want to use
to degas silicone and urethane/resin.

1) Where do you put the oil? (crazy question I know)

2) what oil is acceptable to use I have some Robinair direct drive oil
and in a thread I researched somebody mentioned curt lesker and
company Tv-019 I want as good a vacuum as I can get without recking
the pump, but I am not sure I want to pay Welch Duo seal oil prices.

3) The inlet and outlet ports do not have barbs screwed in does
anybody know of a source for 13/16th 20thread/in barbs (that dont cost
welch prices -60 bucks a piece)

Any other advice/sources would be sincerely appreciated.
Thanks Steve

Check the group archives with google for a fairly recent (6 months, maybe)
thread about a Welch 1405 or 1402 in the subject line. Someone was asking
about an inlet chamber in one post.

Those threads don't sound common for any types of fittings that I'm familiar
with, but check around at auto parts stores, plumbing places, or
appliance/HVAC parts suppliers and maybe you'll find a fitting that you can
adapt barbs to.

Maybe you've already reviewed the Welch site, but I think there were some
application/operation PDF files about general operating procedures for their
pumps.

WB
................

"Scorsi" wrote in message
om...
Hello, I have just bought a Welch 1402 second hand which I want to use
to degas silicone and urethane/resin.

1) Where do you put the oil? (crazy question I know)

2) what oil is acceptable to use I have some Robinair direct drive oil
and in a thread I researched somebody mentioned curt lesker and
company Tv-019 I want as good a vacuum as I can get without recking
the pump, but I am not sure I want to pay Welch Duo seal oil prices.

3) The inlet and outlet ports do not have barbs screwed in does
anybody know of a source for 13/16th 20thread/in barbs (that dont cost
welch prices -60 bucks a piece)

Any other advice/sources would be sincerely appreciated.
Thanks Steve

In article , Scorsi says...

Hello, I have just bought a Welch 1402 second hand which I want to use
to degas silicone and urethane/resin.

1) Where do you put the oil? (crazy question I know)

In the exhaust port.

2) what oil is acceptable to use I have some Robinair direct drive oil
and in a thread I researched somebody mentioned curt lesker and
company Tv-019 I want as good a vacuum as I can get without recking
the pump, but I am not sure I want to pay Welch Duo seal oil prices.

Check the vapor pressure of teh oil you have, if it is for
direct drive vacuum pumps it should work fine. I run the
Leybold direct drive oil in belt driven pumps and it works
fine. The belt drive ones run at a lower speed so if the
oil will stand up to direct drives it will work in a welch
pump.


3) The inlet and outlet ports do not have barbs screwed in does
anybody know of a source for 13/16th 20thread/in barbs (that dont cost
welch prices -60 bucks a piece)

That's a toughie. If you cannot find one from a surplus pump
place, you could thread a piece of brass tubing (there *may*
be an NPT size that is close in OD) to be 20 tpi and then seal
with something like epoxy.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Hello, I have just bought a Welch 1402 second hand which I want to use
to degas silicone and urethane/resin.

1) Where do you put the oil? (crazy question I know)

Pour it into the exhaust port.

2) what oil is acceptable to use I have some Robinair direct drive oil
and in a thread I researched somebody mentioned curt lesker and
company Tv-019 I want as good a vacuum as I can get without recking
the pump, but I am not sure I want to pay Welch Duo seal oil prices.

3) The inlet and outlet ports do not have barbs screwed in does
anybody know of a source for 13/16th 20thread/in barbs (that dont cost
welch prices -60 bucks a piece)

www.duniway.com has the nipples for $20 each. Their prices on oil and
other stuff are usually very good; I've used a lot of their conflat
flange copper gaskets over the years, and they sell all the parts to
rebuild your pump when you need to.

--
Regards,
Carl Ijames carl.ijames at verizon.net

In article , Carl Ijames says...

www.duniway.com has the nipples for $20 each. Their prices on oil and
other stuff are usually very good; I've used a lot of their conflat
flange copper gaskets over the years, and they sell all the parts to
rebuild your pump when you need to.

Ooh. Forgot those folks. They're the ones
keeping my vintage veeco leak checker running.
Very good service.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Someone else may correct me, but I think that any oil will be good
enough for your application. That is I don't think you will notice
the difference between a 5 mm hg vacuum and a 5 micron hg vacuum for
degassing resins.

Dan


(Scorsi) wrote in message

Hello, I have just bought a Welch 1402 second hand which I want to use
to degas silicone and urethane/resin.



2) what oil is acceptable to use I have some Robinair direct drive oil
and in a thread I researched somebody mentioned curt lesker and
company Tv-019 I want as good a vacuum as I can get without recking
the pump, but I am not sure I want to pay Welch Duo seal oil prices.



Any other advice/sources would be sincerely appreciated.
Thanks Steve

In article , Dan Caster says...

Someone else may correct me, but I think that any oil will be good
enough for your application. That is I don't think you will notice
the difference between a 5 mm hg vacuum and a 5 micron hg vacuum for
degassing resins.

If a motor oil has higher vapor pressure constituents
those will be pumped away, possibly compromising the
lubrication qualities of the oil.

Oils in vacuum pumps have to seal, they have to have
appropriate vapor pressures for teh application, and
they have to lubricate - all of these at the operating
temperature of the pump, and without degrading over
time.

If I were him I would charge the pump once with a
reasonable quality vacuuum pump oil, and run it with
the gas ballast valve open as a rule, because he will
be pumping a fair amount of water vapor and also whatever
comes out of his epoxy resin, which is most likely
condensible.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Jim has forgotten more about vacuum systems than I have ever known.
But I can remember reading about using an ordinary motor oil (
probably non-detergent and I am pretty sure it was a single grade oil
like SAE 30 ) in a vacuum pump. The article said the brand and grade,
but since I probably read it before Jim was born, I can not remember
the details.

Dan


jim rozen wrote in message ...
In article , Dan Caster says...

Someone else may correct me, but I think that any oil will be good
enough for your application. That is I don't think you will notice
the difference between a 5 mm hg vacuum and a 5 micron hg vacuum for
degassing resins.

If a motor oil has higher vapor pressure constituents
those will be pumped away, possibly compromising the
lubrication qualities of the oil.

Oils in vacuum pumps have to seal, they have to have
appropriate vapor pressures for teh application, and
they have to lubricate - all of these at the operating
temperature of the pump, and without degrading over
time.

If I were him I would charge the pump once with a
reasonable quality vacuuum pump oil, and run it with
the gas ballast valve open as a rule, because he will
be pumping a fair amount of water vapor and also whatever
comes out of his epoxy resin, which is most likely
condensible.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

In article , Dan Caster says...

probably non-detergent and I am pretty sure it was a single grade oil
like SAE 30 ) in a vacuum pump.

Many of the older piston pumps used straight-weight motor
oil. Actually a check of a leybold, alcatel or pfeiffer
vaccum site might pin down the answer to this question.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

I know people who have used 10w30 mobil 1 but they didn't have good
gauges so I don't know what base pressure they got. For degassing
urethane it would definitely be good enough. Regular motor oils have
additives to get the multiweight rating so you would want a straight sae
30, but the synthetics don't need additives for the 10w rating. I would
definitely expect the synthetic oil to have fewer volatile components.
The standard distilled/refined mineral oil for direct drive pumps
usually has a 19 in the name, like the TV019 someone else mentioned, or
Inland 19, or Invoil 19, etc. This is advertised as either the same as
or one step "better" oil than the duoseal oil used in lower speed belt
drive pumps, which works well in either direct drive or belt drive
pumps. I'm sure you can find a data sheet somewhere online, to get a
viscosity rating, which you can then compare to the motor oil scale to
see if 30 weight is really the best. Oh, heck, the Lakers just didled
away a lead and went to overtime so hang on a sec - okay, I'm back.
From www.sisweb.com (another good source of vacuum stuff), they give
viscosity specs on inland 19 of 54 cst (251 SUS) at 40 deg C and 8.1 cst
(52.7 SUS) at 100 deg C. Normal pump operating temps are in the warm to
just too hot to touch range, or 40-70 deg C. I found
http://www.engineeringtoolbox.com/21_397.html, which gives viscosities
of 9.6-12.9 cst at 99 deg C for SAE 30 and 5.7-9.6 cst at 99 deg C for
SAE 20 motor oil, so SAE 30 may be just a tick on the thick side but
given it's availability I wouldn't hesitate to try it. I also found a
listing for Mobil 1 10W30 as 59 cst at 40 and 10 at 100 deg C, so it's
on the thin side of 30 weights and should work okay. Well, the Lakers
managed to get the win so I'll stop typing :-).


--
Regards,
Carl Ijames carl.ijames at verizon.net

I did a little googling and found http://www.beckerpumps.com/tdl.htm
.
Becker does not make high vacuum pump, but does say their pumps
operate at 0.4 Torr. So not too bad and certainly good enough for
degassing.

Dan


jim rozen wrote in message ...
In article , Dan Caster says...

probably non-detergent and I am pretty sure it was a single grade oil
like SAE 30 ) in a vacuum pump.

Many of the older piston pumps used straight-weight motor
oil. Actually a check of a leybold, alcatel or pfeiffer
vaccum site might pin down the answer to this question.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

I think I goofed the URL for the info on oils. It is

http://www.beckerpumps.com/td1.htm

The last bit is Tee Dee One for tech doc one. At the very end is a
list of various companies and the oil Becker recommends.

Dan


jim rozen wrote in message

Many of the older piston pumps used straight-weight motor
oil. Actually a check of a leybold, alcatel or pfeiffer
vaccum site might pin down the answer to this question.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

(Scorsi) wrote in message . com...
Hello, I have just bought a Welch 1402 second hand which I want to use
to degas silicone and urethane/resin.

1) Where do you put the oil? (crazy question I know)

2) what oil is acceptable to use I have some Robinair direct drive oil
and in a thread I researched somebody mentioned curt lesker and
company Tv-019 I want as good a vacuum as I can get without recking
the pump, but I am not sure I want to pay Welch Duo seal oil prices.

3) The inlet and outlet ports do not have barbs screwed in does
anybody know of a source for 13/16th 20thread/in barbs (that dont cost
welch prices -60 bucks a piece)

Any other advice/sources would be sincerely appreciated.
Thanks Steve

1)&3) As others have said, in the exhaust port, there should be an oil
level glass on one edge of the pump body amd a drain plug right below.
Usually there's an aluminum baffle dingus screwed in the exhaust that
looks like a knob. This has the screwy 20 TPI thread on it. On my
Welch, the intake is a standard pipe thread, I was able to screw in
the adapter tree for evacuating car AC systems with no adapters
needed. Might be there was already a reducer in the port, if so, it
was painted and gunked up to match the body, because I sure don't
remember seeing it. You can also buy, at great cost, a muffler/oil
filter for the exhaust port that supposed to cut down the oil mist and
the noise. I'd like to make one up, but haven't gotten to it yet.
I'd recommend not restricting the outlet with a hose barb, back
pressure is NOT a good thing on these units.

2) I use Mobil Vacuum Pump Oil. I got this at MSC, it was about
$1.50/qt. They had it on the shelf at the local outlet, so no
shipping. From my purposes it worked fine, it's probably meant for
dairy operations and the like. I can get down to the range I need to
dry out the car AC, so it's good enough.

One thing I'm setting up is a reservoir tank set, I'll pump those down
with the inlet shut off, then I can get instant vacuum on my project
when I open the inlet ball valve. I'm thinking of using it on stuff
like small vacuum forming frames and epoxy degassing bell jars where
you need vacuum pronto and can't wait for pump down. I've got a set
of tanks of about 50 liters total volume, that should be enough for
what I want to do.

Stan

In article ,
Stan Schaefer wrote:

[ ... ]

One thing I'm setting up is a reservoir tank set, I'll pump those down
with the inlet shut off, then I can get instant vacuum on my project
when I open the inlet ball valve. I'm thinking of using it on stuff
like small vacuum forming frames and epoxy degassing bell jars where
you need vacuum pronto and can't wait for pump down. I've got a set
of tanks of about 50 liters total volume, that should be enough for
what I want to do.

That sounds useful -- but be careful. Tanks made for pressure
may not be capable of handling a vacuum well. Somewhere out there there
is a photo that someone posted a link to here a few years ago. It was a
tank car -- for natural gas, I think -- which had been undergoing a
steam cleaning when quitting time came. Someone just shut the valves on
it, while it was still loaded with steam, and went home. The steam
condensed, making a partial vacuum, and the tank car crumpled. from the
pressure differential.

Enjoy,
DoN.

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