refrigerator compressor to vacuum pump

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

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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.
>

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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.

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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
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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.
>


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To the contrary it does not work that way at all. If you are replacing a
compressor in a refrigerator you have instant substantial heat if you have
freon in the system. If you have no freon it will take half an hour to get
it barely warm. For this reason it is much to your advantage to take steps
to arrive on the scene with a warm new pump.

Yes we recirculate the oil. The poroblem with some of the usage is that the
subs for 12 will not bring the oil back with them and will deposit it
somewhere not in the compressor.

In our usage catching the oil in an uphill path is definitely a plus.

If you use a refrigerator compressor you have to be careful to keep air
(contains moisture)out of it meaning no leaks or get those leaks fixed.
It is very cheap to start with new bag material each time. I have found
that if you run flat out you don't need a start system and you should be
able to keep it going for the duration.

Start it and let it run till it is warm before you start your wetting with
epoxy. Check your vacuum to make sure you leakage is next to nill.
Catch the oil and you should be able to do many bags with the pump.

If the pump is making frying sissling noises in the morning. When you
disconnect from the bag seal off the end so the vacuum can rise to max and
run it for another twenty minutes to get rid of the moisture that was taken
in and is causing the sizzling.

I finally started using my two stage evacuation pump flat out the same
way only to recoup the money that had been spent on the pump that was not
longer being used.

Don't waste money on extra materials other than a :"T" or two for extra
bags. You are not going to compress the foams we use so that you can
measure it. Medium fuel tubing serves well for joining the system up. Large
fuel tubing probably will collapse . The brand I used did but the medium
was fine. Don't worry about heat in the compressor. Cut off heat is
310F with normal running temperature being too hot to touch. You will never
get there if it is under a good vacuum meaning no leaks. Again no fancy
switchers for tunring it on and off it was meant to be turned on and left on
in normal operation.

Rick
Richard Hallett Pittsfield ME 04967

PS They are normally taken out of operation for noise or failure of the
start mechanism. Most have the 3 pins sticking out of the case with the one
at the top being the common. The one on the right is run and on the left is
start. If you solder pins directly to your cord on the common and main you
will only need an alligator clip to get it going jumping from main to start
during start. Do this way only if you know how to handle 110. Most
people should use an encased momentary switch to get it started. So when
you plug the motor in the start should be engaged on the same side as the
main and it should be instantly released when the motor starts. The problem
with the regular route is that the manufacturer normally wants too much for
these components. If the single pin is on the bottom make the same diagram
and apply it standing on your head. The arrangement is simply upside down
by rotation not mirror

common
start -main

rotated
main-start
common


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

Date: Wed, 22 Jan 2003 10:25:11 -0800
From: "gldr guy" <glderguy@angelfire.com>
To: "Bill Conkling" <conk@widomaker.com>, tomteri22@msn.com, "Ed Berris"
<eberris@mn.rr.com>
Cc: soaring@airage.com
Subject: Re: [RCSE] refrigerator compressor to vacuum pump
Message-ID: <ACKNKOOBLDKFDBAA@angelfire.com>

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 -----

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.
>

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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/

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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"

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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.


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Well, I certainly do not agree with you Richard and am not going to waste my time in debating this issue- but just to touch another aspect of using refrigerator compressors as vacuum pumps-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. I suspect running a compressor at say 12- 14" vac while bagging is probably not the best thing for it. Im through with this topic, thanks, Walter
---
GG

On Thu, 23 Jan 2003 04:44:47
Richard Hallett wrote:
>
>To the contrary it does not work that way at all. If you are replacing a
>compressor in a refrigerator you have instant substantial heat if you have
>freon in the system. If you have no freon it will take half an hour to get
>it barely warm. For this reason it is much to your advantage to take steps
>to arrive on the scene with a warm new pump.
>
>Yes we recirculate the oil. The poroblem with some of the usage is that the
>subs for 12 will not bring the oil back with them and will deposit it
>somewhere not in the compressor.
>
>In our usage catching the oil in an uphill path is definitely a plus.
>
>If you use a refrigerator compressor you have to be careful to keep air
>(contains moisture)out of it meaning no leaks or get those leaks fixed.
>It is very cheap to start with new bag material each time. I have found
>that if you run flat out you don't need a start system and you should be
>able to keep it going for the duration.
>
>Start it and let it run till it is warm before you start your wetting with
>epoxy. Check your vacuum to make sure you leakage is next to nill.
>Catch the oil and you should be able to do many bags with the pump.
>
>If the pump is making frying sissling noises in the morning. When you
>disconnect from the bag seal off the end so the vacuum can rise to max and
>run it for another twenty minutes to get rid of the moisture that was taken
>in and is causing the sizzling.
>
>I finally started using my two stage evacuation pump flat out the same
>way only to recoup the money that had been spent on the pump that was not
>longer being used.
>
>Don't waste money on extra materials other than a :"T" or two for extra
>bags. You are not going to compress the foams we use so that you can
>measure it. Medium fuel tubing serves well for joining the system up. Large
>fuel tubing probably will collapse . The brand I used did but the medium
>was fine. Don't worry about heat in the compressor. Cut off heat is
>310F with normal running temperature being too hot to touch. You will never
>get there if it is under a good vacuum meaning no leaks. Again no fancy
>switchers for tunring it on and off it was meant to be turned on and left on
>in normal operation.
>
>Rick
>Richard Hallett Pittsfield ME 04967
>
>PS They are normally taken out of operation for noise or failure of the
>start mechanism. Most have the 3 pins sticking out of the case with the one
>at the top being the common. The one on the right is run and on the left is
>start. If you solder pins directly to your cord on the common and main you
>will only need an alligator clip to get it going jumping from main to start
>during start. Do this way only if you know how to handle 110. Most
>people should use an encased momentary switch to get it started. So when
>you plug the motor in the start should be engaged on the same side as the
>main and it should be instantly released when the motor starts. The problem
>with the regular route is that the manufacturer normally wants too much for
>these components. If the single pin is on the bottom make the same diagram
>and apply it standing on your head. The arrangement is simply upside down
>by rotation not mirror
>
>common
>start -main
>
>rotated
>main-start
>common
>
>
>----------------------------------------------------------------------
>
>Date: Wed, 22 Jan 2003 10:25:11 -0800
>From: "gldr guy" <glderguy@angelfire.com>
>To: "Bill Conkling" <conk@widomaker.com>, tomteri22@msn.com, "Ed Berris"
><eberris@mn.rr.com>
>Cc: soaring@airage.com
>Subject: Re: [RCSE] refrigerator compressor to vacuum pump
>Message-ID: <ACKNKOOBLDKFDBAA@angelfire.com>
>
>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 -----
>
>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.
>


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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

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