Compressor air line question

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Mar 28, 2006 | 05:25 AM

rednekf350

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From: waterford nj

Compressor air line question

I have a Craftsman 33 gal. compressor and I bought a 25' 3/4" rubber hose to replace the hard coil 1/4" plastic hose that came with it.
When using the stock impact wrench, the air pressure fluctuates and cuts in and out of the tool if you move the tool and hose around.
The hose is brand new, as are the fittings.
There are no kinks and I can't figure out what is happening.
My neighbor said he thinks my disconnects are not compatible with the tool?
I don't know what to try next.
Any ideas?
I am new to air tools and I am tempted to put the stock 1/4" hose back on.
Could it be bumping up the hose size?
Any help will be appreciated.
Scott

Mar 28, 2006 | 06:53 AM

frederic

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From: New Jersey

It's probably due to the new hose having a larger ID than the ID of the outlet on the compressor tank.

If you let the hose "air up" completely to where the compressor shuts off, the tool runs fine briefly, then fluctuates?

I had a similar problem but my particular problem was related to the regulator on the compressor being set for 60psi instead of fully open, which is what impact guns, air grinders, air dremels, air sanders and air saws really need.

I'm assuming you didn't have this problem with the 1/4" coil hose, right?

Mar 28, 2006 | 03:44 PM

rednekf350

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From: waterford nj

I did not have the problem with the 1/4" hose.
The gun that came with the compressor itself is pretty anemic and I thought the larger dia. hose would minimize air friction and give me some more uumph.
I think your theory of the enlargement back at the tank is correct.
I guess I will get some 1/4" hose or put the coil back on.
Thanks for the help.
Scott

Mar 29, 2006 | 01:11 PM

Bart99GT

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The size of the air line, provided it can flow enough air to supply the tool, should be moot. Like an electric device, an air tool only consumes as much air as it requires to operate. My guess would be that the fittings or adapters you used with the new hose are too small and are causing a restriction. Push comes to shove just set the regulator a few PSI higher than you normally do if that's what it takes to keep the pressure constant.

Apr 2, 2006 | 06:40 AM

bterry

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I'll take a bet that it has nothing to do with the diameter of your new hose. A bigger hose will only help, regardless of the opening size at the tank. The length may make a nearly indetectable difference, but would not make it cut in and out. Replace your fittings with a matched (male/female) set. Something is not right here - moving a hose around changes nothing inside the hose. What happens when you hold still?

Quote:

Originally Posted by frederic

If you let the hose "air up" completely to where the compressor shuts off, the tool runs fine briefly, then fluctuates?

This would make a little sense as the hose may act like a VERY small tank, but I don't think you'd be able to notice it after a second or two of running the gun.

Apr 2, 2006 | 06:53 AM

frederic

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From: New Jersey

It makes sense to me because I have a 25' import rubber hose that likes to change it's dimensions. On the compression stroke of the piston the hose inflates slightly, and then swells back down. While the swelling is minimal, you can feel the vibration with your hand, and if you leave the hose lying on the concrete you can see it vibrate slightly, even at the tool end.

That's why I don't use it. I figured it might explode at some point.

Apr 2, 2006 | 09:39 AM

havi

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From: Northshore, MN

replace the impact with a blowgun and see if you feel constant air blowing out. air pressure drop at 25 ft. for a 1/4"ID hose starting at 60 psi is 13 psi, and a 5/16"ID hose starting 60 psi is 4. So as you can see there is a noticeable diff in hose size pressure losses. I'd suggest bumping up your regulator a bit.