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Cast/Invest Table using A/C comp:


Has anyone tried making a quite air compressor using the motor
compressor from an old Air Compressor. I have heard that this could
be done. Can anyone post the directions. Thanks Kenneth


A/C compressors depend on the returning refrigerant to keep them
cool. Also some of the oil circulates through the system with the
refrigerant, I don’t know if this would be enough to cause problems.
If the price is right you don’t stand to lose much if it doesn’t work
well. All i can see you needing is a storage tank, piping, and a
switch to turn it on and off. And don’t forget a releif valve to
prevent overpressurizing. Dan Wellman

    Has anyone tried making a quite air compressor using the motor
compressor from an old Air Compressor. I have heard that this could
be done. Can anyone post the directions. Thanks  Kenneth 

Hi Kenneth,

I did this years ago. I don’t recommend it as the motor does pass a
lot of oil. Don’t do it if you are not mechanically and electrically
inclined. All other disclaimers go her also.

If I forget to list something please forgive me, as I have not even
thought of that compressor for several years. With that said, here it

Parts: compressor and starter from a window mount air conditioner 1 or
2 empty freon tanks power chord with plug switch (I used a wall switch
mounted in a box) pressure controlled switch (turns off the motor when
a preset pressure is reached) a 120 PSI safety relief valve Pressure
gauge (I did not have this luxury item) Water trap/filter copper tube
brass fittings and connectors nuts and bolts plywood base

You will need to scrounge for the compressor motor and freon tanks
Most of the other parts you can pick up at a hardware store. The
pressure control switch, and safety valve you can find at a
compressor repair shop or through a parts company like Grangers.


Attach the compressor to the base using the mounting hardware from
the AC unit.

Attach the freon tanks upside down. “U” bolts through the handles
works. Putting them upside down keeps water from building up in them.

Do all the plumbing. You will need to figure this all out as each
case will be different. You should be able to use brass compression
fittings on the compressor. When cutting the lines be sure to clean
any chips out. Be sure to have the water trap/filter at the end of the
line to catch and oil or condensation.

Connect the black or red wire on the motor to the pressure switch,
the power on/off switch and then to the plug. Connect the white wire on
the motor directly to the plug. Connect the green wire on the motor
directly to the plug.

Good luck.

Timothy A. Hansen

TAH Handcrafted Jewelry
e-mail: @Timothy_A_Hansen

The Printable Finger and Wrist Measuring Tool

End of forwarded message

And don't forget a relief valve to prevent overpressurizing. 

OK, I’m about ready to purchase the components to make my own
Casting/Investment table. Have found a suitable vacuum pump, etc.,
but where do I find a “relief valve” or how do I make one?




Relief valves should be available from any place that sells parts for
air compressors. They are sized to pass more air than the comprtessor
can pump out + the stored air. They usually have a male pipe thread
on the inlet end. Try Graiger’s auto parts stores etc.


Gee, I did open a can of worms concerning my set up, Sorry.

I set the fire bricks 2 high criss-crossed, drilled 2 1"dia. holes
from the side then from the top, then with the torch head coming in
from the side, the flame deflecting upwards I’ve added a 2" x 2 flask
to further divert the flame, By the way my flasks are made of 2"
automotive exhaust pipe, cut as needed and ground flat. Then the
flower pot is wrapped in aluminum foil to help hold it together as it
breaks over multiple uses. I’m on my 10th to 12th++ burnout on one
pot, but have a spare ready…

The U channel beam is 6" wide by 2" tall x ~1/4" material
approximately 7" long (size as found). A hole is drilled through the
large face where the vacuum is admitted by an adapter.

Concerning the glass lid, it worried me at first but after hours of
use, no problem. CORRECTION & NOTICE & DISCLAIMER My lid is not
glass, I believe the Corning “Visions Cookware” is not truely glass,
but a clear ceramic product, simular to what used in the Space
Shuttles (reportedly 11 of 12 of the Challangers clear ceramic windows
servived in usable factory spec condition to the ocean bottom!). I’ve
seen Visions pans go through tortures metal pans would not. Still when
I can find 1’2 thick plexiglass I’ll gladdly switch. . .

Compresor oil - - I use Walmart/K-Mart Air compressor oil though the
vac table as noise dictates (crude). I just adapted the wiring from
the A/C (I have much auto electrical experiance). As far as the
output I don’t use as compressor so I blow the oil into 2 liter soda
bottle, I may recycl/reuse this oil after I get more.

Yes, if the A/C is still preasurized let a pro reclaim the freon a
drop of freon in the eye WILL blind, frozen eyeballs are not
recoverable, ever. One drop of freon will freeze the eye (so I’ve been
taught). Plus freon is a so-called green house / ozone killer?

I hope this coves most remaining gaps.

Oh, the vegitarian crack, sorry if it offended, I’m semi-vegitarian