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(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