# Cheapest vacuum pump



## GoldTJ (Jun 28, 2022)

Cant beat free , as cheapest price 

I'm surprise that most video I see online make use of 200-600$ dedicated vacuum pumps.
Were there are so many source of free freon compressor

Mine cost me 0$ 
It is the Freon compressor from a 12000btu split unit i found in the trash. Control board in the unit was fried 
Refrigerant line were cut , so I had no Freon to adequately dispose. 
Any household traditional unit will also have similar compressor .
If the Freon of the unit have already leak ...the unit buzz...but no cold come out , you may have a great donor. 

Newer inverter type compressor might be more tricky to salvage from , as you may need to savage the 3phases inverter too , to make the compressor work. 

They do "stink" for a wile in the first usage , because the remaining oil in the freon is spited out ,,, It will eventually stop 

I've use it for years , for vacuum castings metals, and plaster
I do squirt a pinch of oil in the intake from time to time to lubricate the internal 

From seen many vacuum filtering on YouTube ,,, my pump does waaaay faster vacuum !


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## Martijn (Jun 29, 2022)

Do you scrub the fumes before it goes through the compressor? 

I'm thinking about a possible reaction between the acid gases and the oil bath the pump sits in. The piston and rotor are lubricated by the oil so they will come in contact with whatever is pumped through.

No idea what that does, but it can't be good. 
I saw a video saying the original oil is hygroscopic which destroyes the unit in time. Add acidic gases and anything can happen...


Martijn.


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## GoldTJ (Jun 29, 2022)

Well, I go true a "reservoir" before going to the pump, just to prevent accidently slurp chemical true the pump 

My pump may get destroy by the remaining acid vapor ,, we will see.


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## FrugalRefiner (Jun 29, 2022)

If you're vacuuming acidic vapors, add a flask with hydroxide between your reservoir and the pump. It will extend the life of your pump.

Dave


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## Palladium (Jun 29, 2022)

I don't know about these type pumps, but i lost several regular HVAC pumps until.... I started using burnt used motor oil in mine. Haven't had to replace a pump in yeasr now. Lot cheaper on the oil side too!


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## Shark (Jun 29, 2022)

Palladium said:


> I don't know about these type pumps, but i lost several regular HVAC pumps until.... I started using burnt used motor oil in mine. Haven't had to replace a pump in yeasr now. Lot cheaper on the oil side too!


Been using new 30 weight in mine for two years now. But then I did learn that trick from you as well.


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## FrugalRefiner (Jun 29, 2022)

FrugalRefiner said:


> If you're vacuuming acidic vapors, add a flask with hydroxide between your reservoir and the pump. It will extend the life of your pump.
> 
> Dave


Oops! I just read my post. It's wrong.

Add the flask with hydroxide between the reservoir and the reaction vessel. I agree with the reservoir to prevent the "slurp". Putting the hydroxide before the reservoir is the right way. It will scrub the acidic vapors and the reservoir will still prevent the slurp.

Dave


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## Shark (Jun 29, 2022)

Wow, I read that twice and still missed it. Good catch Dave.


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## Martijn (Jun 30, 2022)

Palladium said:


> I don't know about these type pumps, but i lost several regular HVAC pumps until.... I started using burnt used motor oil in mine. Haven't had to replace a pump in yeasr now. Lot cheaper on the oil side too!


As the man in the video says also. Good to hear you agree.


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