Jun-Air Compressor

[jdonahoe6]

Hey guys, first post here, and its a question.
I recently received a free Jun-Air compressor. Evidently they are used in the medical field and they are no louder than an electric toothbrush when turned on. The compressor runs my air ratchet fine, and it says it is running 120 PSI on the gauge, and I removed the regulator and it still won't run my impact gun. Does anyone know of anyway to increase the air volume on these? I have checked the JUN-AIR website as well as the search function here and can't find any info.
Here are the stats on the compressor:
120 PSI
120v/60Hz
40 Liter/10.5 Gallon
12.4 amps

Thanks for looking and any help would be appreciated.

 

[reptilezs]

how big is the current tank? you can piggy back a 7-10 gall portable tank or add a tank from a dead compressor

 

[jdonahoe6]

The current tank is 40 liters/10.5 gallons

 

[Olafur]

No matter what size compressor you have - a 40 liter tank @120 psi should run 3/8 and 1/2" impacts. Enough to remove few lug nuts at a time before the pressure drops to much.

Jun-air are pretty good compressors, silent, but have very limited air flow. I am not aware of any method of increasing their flow. If your unit fills the tank up to 120 psi it is probably in working order, but I am guessing it takes several min. Do not expect to be able to use 3/8 impact continuously, you probably have to wait few minutes between each burst.

 

[jdonahoe6]

So do you think that I should get a 3/8 inch impact gun and try that? My hose is 3/8" Goodyear hose, would a half inch hose benefit in this situation?

 

[Olafur]

What type of impact gun to you have, and how does it behave exactly (you say your gun does not run)? If your 40 liter tank goes up to 120 psi a 1/2" gun should work for short while if connected directly to the tank, i.e enough to remove few lug nuts at a time. Usually 1/2" guns hits a bit harder with 1/2" hose than 3/8"..and the difference increases with hose length. If your gun does not run at all with 3/8" hose switching to 1/2" will hardly solve the problem.

 

[jdonahoe6]

I have this harbor freight impact gun
http://www.harborfreight.com/1-2-half-inch-composite-air-impact-wrench-66886.html
At the highest setting it has less torque than my air ratchet, I know the gun isn't defective as I've used it on other smaller compressors and it has removed lugnuts and tyrod end bolts.
The hose is 25 feet long, although I have attached the gun directly to the compressor and it still won't impact with any sort of torque.

 

[reptilezs]

that 10 gal tank should run the impact for a bit before the compressor cycles. look for flow restrictions. post a pic of your setup

 

[Identaltech]

I hope it doesnt look anything like this one.

very low volume of air output and you must use their oil.
It has no rings on the piston.
if its the DentalEz jun air compressor its a little better.
all the 1/4 in fittings will choke the air off.
you will be lucky to get 2 or 3 cfm out of it.
we pull them out of offices all the time because they cant keep up with one dental drill after a few years of use.
piggy back another tank will only give you short bursts but you will deplete your air because it cant keep up.

 

[Olafur]

I have this harbor freight impact gun
http://www.harborfreight.com/1-2-half-inch-composite-air-impact-wrench-66886.html
At the highest setting it has less torque than my air ratchet, I know the gun isn't defective as I've used it on other smaller compressors and it has removed lugnuts and tyrod end bolts.
The hose is 25 feet long, although I have attached the gun directly to the compressor and it still won't impact with any sort of torque.

To the compressor or to the tank?

And like reptilezs suggested - pics from your setup could help us help you.

 

[jdonahoe6]

I'm away at school right now, so I wont have a picture until Friday night when another car inevitably breaks at my house. But this is the exact compressor I have, I'm a rookie when it comes to compressors, so I dont understand what much of this means.
http://www.jun-air.dk/product_detail.aspx?ProductID=635&ProductTypeID=50

 

[jdonahoe6]

To the compressor or to the tank?

And like reptilezs suggested - pics from your setup could help us help you.

Directly to the tank, as I said, I won't be able to have pictures until friday night.

 

[reptilezs]

what size fitting on the tank? 1/4 npt? that could be it or the pressure gauge is wrong

 

[doodah man]

We use these compressors at my work to run valves on electron microscopes. The requirement is that they be quiet and maintain a constant pressure. They don't need to provide any sustained flow. I don't use a lot of air tools, but from what I read, the critical parameter is the flow (cfm). I was thinking about grabbing a air impact for a job, but it required something like 12 cfm and my little pancake compressor only puts out 1.5.

 

[jdonahoe6]

what size fitting on the tank? 1/4 npt? that could be it or the pressure gauge is wrong

I have a 1/4 to 3/8 inch adapter coming directly from the tank to a ball valve, which is wide open. I have removed anything extra in between the tank and the impact wrench.