refrigerator compressor to vacuum pump

anybody ever converted a refrigerator compressor to a vacuum pump?
Please let me know how to.

RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

Should be a matter of supplying the proper fittings, and a inlet filter to
keep out trash.

..........bc (conk@widomaker.com

http://www.widomaker.com/~conk
Williamsburg, VA 23185


On Wed, 22 Jan 2003, nwass222 <tomteri22@msn.com> wrote:

> anybody ever converted a refrigerator compressor to a vacuum pump?
> Please let me know how to.
>
> RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.
>

RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

Not quite right. Refrigeration compressors use oil for cooling. In
addition, this pump type is closed to that the oil within stays there but
when used for vacuum bagging you have an open system. It is necessary to
run a piece of hose from the outlet side up towards the ceiling. In fact,
you can anchor it to the ceiling. Any oil that squirts or mists out will
remain in the tube and flow back to the pump. In the absence of this you
will have quite a mess to deal with.

Frankly a much better solution is a rotary vane vacuum pump.

It is not all that uncommon for an old refrigeration pump to fail. If you
have a wing that you are bagging when failure happens you have wasted a lot
of time, energy and materials.

Vacuum pumps are available from surplus dealers, from e-Bay and from me.

Prices will range from $25 to around $150.

Why screw around with a second best solution when you can get a good,
reliable rotary vane pump designed for 24/7 operation. You are compromising
the quality of your work.
Ed



----- Original Message -----
From: "Bill Conkling" <conk@widomaker.com>
To: <tomteri22@msn.com>
Cc: <soaring@airage.com>
Sent: Wednesday, January 22, 2003 10:34 AM
Subject: Re: [RCSE] refrigerator compressor to vacuum pump


> Should be a matter of supplying the proper fittings, and a inlet filter to
> keep out trash.
>
> .........bc (conk@widomaker.com
>
> http://www.widomaker.com/~conk
> Williamsburg, VA 23185
>
>
> On Wed, 22 Jan 2003, nwass222 <tomteri22@msn.com> wrote:
>
> > anybody ever converted a refrigerator compressor to a vacuum pump?
> > Please let me know how to.
> >
> > RCSE-List facilities provided by Model Airplane News. Send "subscribe"
and "unsubscribe" requests to soaring-request@airage.com. Please note that
subscribe and unsubscribe messages must be sent in text only format with
MIME turned off.
> >
>
> RCSE-List facilities provided by Model Airplane News. Send "subscribe"
and "unsubscribe" requests to soaring-request@airage.com. Please note that
subscribe and unsubscribe messages must be sent in text only format with
MIME turned off.

RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

On Wed, Jan 22, 2003 at 03:44:32AM -0000, nwass222 <tomteri22@msn.com> wrote:
> anybody ever converted a refrigerator compressor to a vacuum pump?
> Please let me know how to.

It works fine, although if you have the cash a real vacuum pump is
better. Do follow the advice about dealing with the oil in the
system, as it does make a royal mess. I think the RCSE archives have
some more info on fridge compressors.

I'm assuming that you've read all that Google finds on the subject?
If not, try:
http://www.google.com/search?sourcei...tor+compressor

Also, do note that the reason most fridges are junked isn't because
they lack the modern conveiences of a keg-tap and well-lit water
dispenser; rather people seem to trash them because the compressors
are failing. Newer ones seem to work much better, but it's a shame to
vent the freon on a good one. For the amount of bagging I do (and the
materials I'd lose if the pump failed during a project), the
cost/benefit is quite obvious. If you're putting $50 of Kevlar and
Carbon into a wing getting it right the first time would be more
important than if you have 2 yards of 1.5oz glass invested

If you have access to a good compressor and can safely hook it up to
a vacuum switch of some sort, I'd say go for it. It's a fun project,
and if you end up doing more bagging maybe you'll buy a real pump.
There is some satisfaction in watching my roommate try to puzzle out
my contraption

-Peter

--
Peter Jensen ... http://www.diff.net/peter ... jensen@cc.gatech.edu
RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

Not quite right again. Sealed hermetic refrigeration compressors use oil primarily for lubrication. They depend on cold refrigerant returning from the evaporator via the suction line to cool the windings in the compressor motor. If you are serious about this go to the local refrigeration parts supplier and spend the bucks on a refrigeration vacuum pump(they arent cheap)- you can run them for days at a time and they are capable of pulling a large system, providing it is tight, down to less than 500 microns and 29.9 inches of vacuum- bagging wings for them is a piece of cake, just add a vacuum regulator so you can adjust your vacuum. Walter
---
GG

On Wed, 22 Jan 2003 10:42:16
Ed Berris wrote:
>Not quite right. Refrigeration compressors use oil for cooling. In
>addition, this pump type is closed to that the oil within stays there but
>when used for vacuum bagging you have an open system. It is necessary to
>run a piece of hose from the outlet side up towards the ceiling. In fact,
>you can anchor it to the ceiling. Any oil that squirts or mists out will
>remain in the tube and flow back to the pump. In the absence of this you
>will have quite a mess to deal with.
>
>Frankly a much better solution is a rotary vane vacuum pump.
>
>It is not all that uncommon for an old refrigeration pump to fail. If you
>have a wing that you are bagging when failure happens you have wasted a lot
>of time, energy and materials.
>
>Vacuum pumps are available from surplus dealers, from e-Bay and from me.
>
>Prices will range from $25 to around $150.
>
>Why screw around with a second best solution when you can get a good,
>reliable rotary vane pump designed for 24/7 operation. You are compromising
>the quality of your work.
>Ed
>
>
>
>----- Original Message -----
>From: "Bill Conkling" <conk@widomaker.com>
>To: <tomteri22@msn.com>
>Cc: <soaring@airage.com>
>Sent: Wednesday, January 22, 2003 10:34 AM
>Subject: Re: [RCSE] refrigerator compressor to vacuum pump
>
>
>> Should be a matter of supplying the proper fittings, and a inlet filter to
>> keep out trash.
>>
>> .........bc (conk@widomaker.com
>>
>> http://www.widomaker.com/~conk
>> Williamsburg, VA 23185
>>
>>
>> On Wed, 22 Jan 2003, nwass222 <tomteri22@msn.com> wrote:
>>
>> > anybody ever converted a refrigerator compressor to a vacuum pump?
>> > Please let me know how to.
>> >
>> > RCSE-List facilities provided by Model Airplane News. Send "subscribe"
>and "unsubscribe" requests to soaring-request@airage.com. Please note that
>subscribe and unsubscribe messages must be sent in text only format with
>MIME turned off.
>> >
>>
>> RCSE-List facilities provided by Model Airplane News. Send "subscribe"
>and "unsubscribe" requests to soaring-request@airage.com. Please note that
>subscribe and unsubscribe messages must be sent in text only format with
>MIME turned off.
>
>RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.
>


__________________________________________________ __________
Get 25MB of email storage with Lycos Mail Plus!
Sign up today -- http://www.mail.lycos.com/brandPage.shtml?pageId=plus
RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

er, no.

The compressors on refrigerators are designed to be cooled by the
refrigerant and also lubricated by the synthetics in the refridgerent. Also,
the compressor is deisgned to deliver pressure and not draw a vacuum.

I would say it was unsuitable and although it might work for a while making
a small vacuum, it would not last long.

Also, be aware, that an old compressor is not likely to last long.. They
dont last long as it is, mainly due to lubricant loss. a large proportion of
refrigerent 'experts' are nothing more than a guy with his bottle of gas,
whcih dont usualy have the lubricant in them. If the fridge (ah, the english
term) has lost gas (they do, hence they stop getting cold and the compressor
runs for ever) then it will have lost lubricant as well.

My 2pw
--
Veronica Merryfield, somewhere in Cambridgeshire, UK
"The best things in life aren't things"




----- Original Message -----
From: "Bill Conkling" <conk@widomaker.com>
To: <tomteri22@msn.com>
Cc: <soaring@airage.com>
Sent: Wednesday, January 22, 2003 4:34 PM
Subject: Re: [RCSE] refrigerator compressor to vacuum pump
>
>
> > Should be a matter of supplying the proper fittings, and a inlet filter
to
> > keep out trash.
> >
> > .........bc (conk@widomaker.com
> >
> > http://www.widomaker.com/~conk
> > Williamsburg, VA 23185
> >
> >
> > On Wed, 22 Jan 2003, nwass222 <tomteri22@msn.com> wrote:
> >
> > > anybody ever converted a refrigerator compressor to a vacuum pump?
> > > Please let me know how to.
> > >
> > > RCSE-List facilities provided by Model Airplane News. Send
"subscribe"
> and "unsubscribe" requests to soaring-request@airage.com. Please note
that
> subscribe and unsubscribe messages must be sent in text only format with
> MIME turned off.
> > >
> >
> > RCSE-List facilities provided by Model Airplane News. Send "subscribe"
> and "unsubscribe" requests to soaring-request@airage.com. Please note
that
> subscribe and unsubscribe messages must be sent in text only format with
> MIME turned off.
>

RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

nwass222 wrote:
> anybody ever converted a refrigerator compressor to a vacuum pump?
> Please let me know how to.

Had you checked my bookmarks ...
http://members.ozemail.com.au/~flyingwing/vacbag/

--
Andrew E. Mileski
Ottawa, Canada
http://isoar.ca/

RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

Sorry but working on domestic refrigerators we are not normally worried
about pressure we test to see if it will draw a vacuum. Its most important
characteristic is its ability to draw a vacuum. If there is no vacuum the
refrigerator is DEAD. It can still have pressure with a valve on the low
side gone. There is nothing in the refrigerant to lubricate. The concern we
have is whether the refrigerant will carry the oil with it . This became a
major sticking point for the subs for 12.

The major killer for a compressor in this use is the loss of oil out the
pressure side or the contamination of the oil with water so that it froths
and does not lubricate. When you get water or antifreeze in your cars
crankcase you shortly say good bye to the bearings. This is no different.
In addition the moisture can start the formation of acid which will eat the
motor windings which are in the same oil solution. If you do not pump
moisture through this pump at a high speed they will last a surprisingly
long time. The water is coming from the moisture in the air that is coming
in that leak in the bag.

If you discover a refrigerator that is low on gas you look for oil on the
floor to see if it is condenser leak but you will not find oil if you have
a low pressure side evaporator leak. Sure wish you did. This is where you
pull your hair out looking .

For ten years now we have not been allowed to add gas. You technically must
attempt to find the leak.

Contrary to most service contractors I like doing refrigeration because
normally you can easily beat the allotted time. I normally give away a half
dozen or so compressors for this use each year. Most are quite successful
with them.

Rick
Richard Hallett Pittsfield ME USA

Date: Wed, 22 Jan 2003 22:16:32 -0000
From: "Veronica Merryfield" <veronica.merryfield@tesco.net>
To: <soaring@airage.com>
Subject: Re: [RCSE] refrigerator compressor to vacuum pump
Message-ID: <011101c2c263$ebb5b460$6401a8c0@pooh>

er, no.

The compressors on refrigerators are designed to be cooled by the
refrigerant and also lubricated by the synthetics in the refridgerent. Also,
the compressor is deisgned to deliver pressure and not draw a vacuum.

I would say it was unsuitable and although it might work for a while making
a small vacuum, it would not last long.

Also, be aware, that an old compressor is not likely to last long.. They
dont last long as it is, mainly due to lubricant loss. a large proportion of
refrigerent 'experts' are nothing more than a guy with his bottle of gas,
whcih dont usualy have the lubricant in them. If the fridge (ah, the english
term) has lost gas (they do, hence they stop getting cold and the compressor
runs for ever) then it will have lost lubricant as well.

My 2pw
--
Veronica Merryfield, somewhere in Cambridgeshire, UK
"The best things in life aren't things"

RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

If anyone in SoCal is interested in fooling around with a fridge
compressor I have one in working condition that is free to anyone
who wants it. Will go in the dumpster next week otherwise.

CG.




----- Original Message -----
From: "Andrew E. Mileski" <andrewm@isoar.ca>
To: <soaring@airage.com>
Sent: Wednesday, January 22, 2003 2:35 PM
Subject: Re: [RCSE] refrigerator compressor to vacuum pump


> nwass222 wrote:
> > anybody ever converted a refrigerator compressor to a vacuum
pump?
> > Please let me know how to.


RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

Walter writes:

>...energizing the electrical windings on a compressor motor while in a
>vacuum will eventually do serious damage to them. It is a cardinal rule in
>the trade to never energize compressor windings while in a vacuum...

There's an easy fix for that problem. I had a similar issue with a vane
pump I was using to bag wings, equipped with a pressure switch to cycle it
on and off. The load on the pump from the vacuum would stall the motor
during startup. I simply installed a check valve in the line to the pump (I
used a rubber reed type aquarium check valve from my local pet shop,
they're cheap, and have very little opening pressure requirements), then
poked a tiny hole in the line with a needle between the check valve in the
pump. The leakage from this hole was insignificant while the pump was
running. When the pump shut down, the tiny hole would bleed off the vacuum
in the line to the pump, while the check valve held the vacuum in the line
to the bag. When the pump started up, there was no vacuum load on it for
that crucial first few revolutions. Note, the connection to the pressure
switch needs to be between the check valve and the bag for this system to work.


Don Stackhouse @ DJ Aerotech
djaerotech@erinet.com
http://www.djaerotech.com

RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to soaring-request@airage.com. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.

[McMillan]

It seems to me that the problem here is retaining and reusing the oil which may be purged from the compressor.

Perhaps you could keep the pump lubricated and your atmosphere free of oil if you use an oil / water separator on the outlet, and a drain with a recirc loop to the suction side. Your separator could simple be a can with polyester fill or foam so the oil could drain down to a sump and get sucked up at the inlet again.

Maybe a small ball valve could be used to control / regulate the flow of the trapped oil while it's running once in a while.

I like the check valve idea with the pin hole for handling startup stalls. Perhaps a T with a small valve could be used in stead.

I know Home Depot has hundreds of fittings, valves and adaptors for copper pipe.

Most of you should be able to reach SMC Pneumatics over the web or locally to pick up the other stuff. Guages, regulators, fittings, flex tube, etc..