Now, I have a compressor from an old fridge, I want it to use

Do you have an actual pic of the Compressor?

>>1162180
nope, I'll take a closer look at it in a few days, but it's from a small fridge, whose whole power rating, if I remember correctly was 100w.

also, as I handled it, upon quicker movement it made cloncking sound, whole inner assembly hitting a wall. As far as I found out, the inner assembly is hanging on springs, but are they loose enough for it to hit the walls? Or is it just broken?

>>1162185
no, thats how every fridge i've moved has sounded


i dunno what kind of oil you're supposed to use, but if it originally had R134a refrigerant, it probably used PAG oil (or it will say on the label). that stuff is pretty hygroscopic.

how do you drain a hermetically sealed compressor anyway?

The Oil exposed to the Atmosphere will get acid an hurt the Isolation of the Copper windings.

Btw. The Compressor will need some kind of Cooling like an Fan or so (the suction Gas like in an working Fridge is now missing).

Sorry my English is not so good.

>>1162188
I remember that the sticker on it said 600a refrigirant. Well, anyways, the compressor is not meant to be used as a vacuum pump with ordinary air, but I just figured I can try to push the max out of it, till is shits the bed.
I found videos of people opening processing pipe, tipping it over to let out the oil. But I couldn;t finde definitive answer on oil and such, so I thought It might not be worth of dicking around with oil at all.
>>1162192
yeah, I read something similar in youtube comments. But what oil should I use? Also, how does the piston get lubricated? Does it get the oil little by little from the bowl?

>>1162188
>how do you drain a hermetically sealed compressor anyway?

It's only sealed if you don't cut the refrigerant lines.

Tip it so the exhaust line is lowest point and much will drain out.
Tip it so the intake line is lowest point and some more may drain.
Hook a flexible line to the intake tube and allow it to suck up a couple of ounces of mineral oil.
(don't have more oil in the cup than you want sucked into the compressor)

If you repeat the drain and fill it will have mostly mineral oil in it.

And install some kind of Filter at the Suction Line (big Pipe) and at the 3. Port, the Service Port.

>>1162177

watch a youtube videos, lots of people have done this already.

>>1162196
propane/isobutane
OP is in Europe

>>1162198
Could you elaborate on the inner working of the compressor? What is sealed from what?
I thought that the piston isolates the inner assembly from the sucktion and compression lines?
How does the oil get in?

>>1162204
https://www.youtube.com/watch?v=JnUx8SXJMQ4

>>1162207
well, I don't speak german, but after a few videos this is what I figured out. Correct me if I'm wrong.
The piston chamber is connected to the compression pipe.
The suction pipe is connected to the whole inner cavity.
As a vacuum is pulled, the whole inner volume becomes vacuumed?

>>1162177
>some allegedly have it used for several years without any oil

I've used three for the last five years, never changed any oil - they all work exactly the same as when I first started using them.

I use them for Resin Casting.

>>1162177
easy if you are going to use it for something like painting. yes you need new oil and other things.

if you are going to use it for vacuum no need. if you need more vacuum yes maybe but dont worry that compressors could get that shity air. anyway they are easy to find if your get broke.

File: venturi-vacuum-pump-schematics.jpg (43KB, 628x390px) Image search: [Google]

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Not to make a new thread about this - has anybody here tried making a vacuum pump using a venturi vacuum generator and a regular air compressor with a tank?

If it's R600a then it will have mineral oil and you don't need to change it. Refrigerator compressors don't reach a deep vacuum but will suffice for shits and giggles like boiling water. Use a filter on the intake to prevent crap getting into the innards of the compressor.
The internals are spring loaded and will bang against the housing when you handle it. Keep it level when running and it will be fine.

>>1162782
cool, thanks for the info. Could you comment on these, are these right, because I'm just curious:
The piston chamber is connected to the compression pipe.
The suction pipe is connected to the whole inner cavity.
As a vacuum is pulled, the whole inner volume becomes vacuumed?
Cause I'm thinking, if the whole inner volume is being vacuumed, the heat removal from coils would drop dramatically.

>>1162763
never made one but used to use them all the time in chemistry class. fitted to tap, running water creates vacuum. amazing.

>>1162852
Correct on all counts.
Worse: In normal operation the coils and compressor are cooled by cold refrigerant gas returning from the evaporator, not just ambient temp stuff.
But really, you don't care because you're not actually compressing gas, which is what causes the vast majority of the heat under normal operation (=current through the coils + heat from compression). It's unlikely to overheat if you use it just to suck a vacuum, even if you do it for a long time.

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>>1162890
Thank you very much, now my curiosity is taken care of.