Air compressor as a vac pump?

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leehljp

leehljp

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I purchased a HF pressure tank (while in the States) for stabilizing blanks and it arrived a here couple of weeks ago. I have been looking for a vacuum pump and cannot find one in the Nagoya area. I have an idea of where I might get on if I were in Osaka but that is several hours away.

Besides one of those hand brake vac, which I figured out I will not use - I have a 1 HP 3 gallon air compressor.

MY QUESTION IS: Can the INTAKE side of an air compressor be used to pull vaccum? Upon inspection it would be easy to take the intake filter off and install the fittings to hook up to the vac line to the pressure tank.

Back in my younger days, I would have tried this without hesitation, but now I prefer to check with some who know the problems of using an air comp for this purpose.

Your opinions?


Oh yes, I know about venturi pumps and cannot find those either. Thought about ordering one from HF but it will take a couple of months at the least to get it delivered to my daughter in the US and have her send it here.
 
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Oh yes, I know about venturi pumps and cannot find those either. Thought about ordering one from HF but it will take a couple of months at the least to get it delivered to my daughter in the US and have her send it here.
Click to expand...

In principle it should work but it would seem a check valve would be needed on the intake side.
Alterntivley speaking an old HVAC or refgerator compressor might be a better choice scroll type if available.No sense risking a new compressor even if it did come from HF.
I would consider going to my local HF buying and shipping the venturi unit to you if that route might be an option and shipping from the states isn
t too expensive.
Another thought would be to contact Frednc.He bought one a while back and said he couldn't get it to work but I have the same unit and with the proper plumbing it works like a champ.Maybe he would sell you his.
That being said

I'm not real good on Geography but aren't you already in the general vicinity of where the HF stuff comes from?
I have read too often that someone is waiting for stuff that is back ordered because it is in transit.
If I understand this correctly the article is made in China or Taiwan, shipped to the States and then shipped back to you?
It seems like there is something wrong with this picture.
Are there trade restrictions?
 
Hank, The set-up Eagle uses is the easiest. The Venturi is really cheap at HF.

Eagle's other option the Refrigerator Compressor, has a Vacuum side, many have used this.

Another is a Hospital Vacuum pump at a Surplus place. Would want to ensure proper decontamination...
US Military Operates Salvage Yards Worldwide. DOD Reclamination...

Hopefully Eagle and I have helped....
 
The main reason I asked about the air compressor is that is about the only thing I have access to over here. Recycled Air Conditioner units are tightly controlled. None laying around to pickup. I could get a small refrigerator but the getting rid of the carcass would cost about $100.00 Dumps charge an arm and a leg and won't take just anything. They don't like AC/refrigeration units with or without the compressor.

The rules over here are dumb. I had about 30 boxes of printed material left over from the World Expo last year (Habitat for Humanity Booth). Took them to the Garbage disposal (dump). They wouldn't take it because they were full glossy print. "Take them to a re-cycle place for paper" I was told. At the re-cycle place for paper they wouldn't touch them. "Take them to the garbage disposal (dump)." Called a "for hire" garbage pick-up. Cost me $5.00 a box. And that is just paper!

I am back to either the air compressor or getting my daughter to get me a venturi unit from HF. I will look for a check valve locally and order an HF unit to be delivered to my USA home for my daughter to send.

Thanks Eagle for the offer. It is appreciated.
 
Hank, I have been using an old crankcase oil type,1 cylinder piston air compressor with a ½ HP motor, for a couple of years. It works very well, that said I don’t know if it is safe or an accident about to happen. This one does not have a tank and I hooked into the inlet side of the compressor and leave the outlet open. Is there some way you can bypass the tank and regulator, I think all of the fumes in the tank could make a nice bomb. I have mine setting behind a piece of plywood to catch the parts if it ever comes apart.
One thing I did not say is I just run this about a minute or two at a time so that it dose not buld up any heat, then let it relax and cool then do it again and again untill all the bubbles are gone.
Bob
 
YOU know, I never thought of the fumes exploding if they built up in the tank.
That venturi vacuum for $9.99 is looking better all the time.
Do you really think the plywood is going to stop anything?
Is there a market for plywood bullet proof vests?
 
Hank,
As I understand the venturi pumps, a steady 90-100psi is needed to make them work effectively. That is what I was told. No instructions in the HF unit packaging. Maybe someone who uses the venturi pump will authenticate that info...is 90+ psi needed...constantly...for the venturi pumps for work? HF actually has two units whose price differs by about $10 if I remember correctly.
Do a good turn daily!
Don
Originally posted by leehljp
<br />
Oh yes, I know about venturi pumps and cannot find those either. Thought about ordering one from HF but it will take a couple of months at the least to get it delivered to my daughter in the US and have her send it here.
Click to expand...
 
Originally posted by its_virgil
<br />Hank,
As I understand the venturi pumps, a steady 90-100psi is needed to make them work effectively. That is what I was told. No instructions in the HF unit packaging. Maybe someone who uses the venturi pump will authenticate that info...is 90+ psi needed...constantly...for the venturi pumps for work? HF actually has two units whose price differs by about $10 if I remember correctly.
Do a good turn daily!
Don
Originally posted by leehljp
<br />
Oh yes, I know about venturi pumps and cannot find those either. Thought about ordering one from HF but it will take a couple of months at the least to get it delivered to my daughter in the US and have her send it here.
Click to expand...
Click to expand...

90lbs is right but if you add a ball valve at the in put side of the
unit to control the amount of air creating the vacuum and another on the suction side to close off the chamber the comprssor doe not need to run continuously.
When I am using it I monitor the Vac. gauge and "cyc'e it as the vac gauge needle drops(Usually every couple of hours or so.
It depends on how fast the material "gives up" the iar and if I have any leaks.
 
Didn't think about the fumes building up in the tank! [B)] But that is why I asked. I needed to know what I was missing! Now I do!

Venturi and 90 PSI. My compressor is not that big. [:(] My hand pump is looking friendly again.
 
I am not sure what PSI is required(I really don't understand those things but the CFM's required is 4.2.
Here's the model #3952 do aearch on their site.
Here's the link to HF http://www.harborfreight.com/
I have used the hand break bleeder(2 years ago) and when the acetone fumes melted the gauge and valve, bough this one and have never looked back.
One cautionary note.
It is wise to keep the venturi unit higher than the vacuum chamber(DAMHIKT)
 
The plywood is just to catch the head if it decides to blow. This old compressor is just about the size of a 3 HP gas engine cast iron about the only thing that would happen is it might blow the head off of it as it does have smaller head bolts than the gas. If you have a 1 cylinder gas engine put a pulley on the crankshaft and a electric motor to turn it over, then remove the carburetor, hook on a suction line in it’s place to go to your pot and it will pull a vacuum. A compressor is about the same thing it is just not made for the gas to explode in.
My concern is if a person gets a spark anywhere near where you are pulling this vacuum of fumes of a highly explosive material it does not matter what you are using, a spark and it will go bang.
Bob
 
Kaspar,

Thanks for posting that link. That looks exactly/precisely like a pump I have seen here at a high end hobby shop - too expensive IIRC. (The top, the base, the handle but without the canister.) That tells me that the vac pump basically the same except it uses the intake side for vac rather than the output side for pressure.
 
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