1/2 inch impact wrench on small compressor

I have a (new) 3 gal 1.25hp Craftsman air compressor that I tried using a (new) Campbell Housfield 1/2 inch air impact wrench with....

The compressor works fine for airing tires, pool floats, etc.....

The impact wrench will not work when hooked to this compressor....it just hisses as if the air is just passing thru the impact wrench without engaging the wrench mechanism....

Is this because the 3 gal tank is not enough air volume to work the impact wrench...??

Is it because the 1.25hp is not enough hp to keep the air flowing at maximum flow rate...??

Rickie

What's the pressure on the tank? Has the gun worked with a different set up?

Most 1/2 consumer impact wrenches require between 3-5 SCfm @ 90lb. as a minimum. Ck the mfg. minimum air requirements, and I'll bet your nowhere near those.

If it would work with your set up, you wouldn't have enough pressure to acually do anything with the gun. EB

Hose size is a determiner as well, especially on air tools. Your compressor and tools may match up on CFM and pressures, but if you can't supply the air volumes at the tool end of the air line, same problem. Some of my small demand tools will run on a 3/8" hose, but most require 1/2". Small compressors such as the one you described, often come with a coiled 1/4", and were never intended to supply enough air for anything other than running inflators and small brad and nail guns. Continuously rotating air tools gobble air.

You should have enough air to at least turn over the wrench. If it is only hissing, check the forward and reverse leaver or push pin. Shift them back and forth several times. Some time they won't shift all the way. Ditto on small hose and volume. I have a 7gal that air tools will bring to it's knees in a hurry. Just don't expect to much from that compressor.

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Originally Posted by cray

You should have enough air to at least turn over the wrench. If it is only hissing, check the forward and reverse leaver or push pin. Shift them back and forth several times. Some time they won't shift all the way. Ditto on small hose and volume. I have a 7gal that air tools will bring to it's knees in a hurry. Just don't expect to much from that compressor.

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I agree it should work for short time is the hose is large enough.
I have a 20 gal tank and a 4hp compressor and most tools will use it up fast. But if you work a little and let it recover then work again they still work ok.

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Originally Posted by boatstall

Hose size is a determiner as well, especially on air tools. Your compressor and tools may match up on CFM and pressures, but if you can't supply the air volumes at the tool end of the air line, same problem. Some of my small demand tools will run on a 3/8" hose, but most require 1/2". Small compressors such as the one you described, often come with a coiled 1/4", and were never intended to supply enough air for anything other than running inflators and small brad and nail guns. Continuously rotating air tools gobble air.

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My compressor indeed has the coiled yellow plastic hose......so my suspicion is not enough volumn...

I will buy a larger hose and see if that helps at all....

Thanks guys...

Rickie

I think you need a bigger compressor, or am I wrong? I also don't own one...

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Originally Posted by cray

You should have enough air to at least turn over the wrench. If it is only hissing, check the forward and reverse leaver or push pin. Shift them back and forth several times. Some time they won't shift all the way. Ditto on small hose and volume. I have a 7gal that air tools will bring to it's knees in a hurry. Just don't expect to much from that compressor.

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I agree with this, if it isn't turning over at all then it is something to do with the wrench.

some air wrenches have a varible speed/power. see if the foward/reverse knob will turn or sometimes it is on the bottom of the grip. hold trigger down and turn

get a decent hose and it should work. I have a similar size compressor and use a 1/2" impact wrench to rotate the tires on my cars, and remove the blades on my ZTR as well. Granted, it will give the compressor a workout, but mine works pretty good considering the compressor's size. first time I removed the blades on the ZTR I really had to bang on the bolts with the wrench for a while, and would have to wait for the compressor to build back up. Put some anti-seize on the bolts and solved that problem. Hit 'em one time now and they are free.

I've found that when breaking the bolts free, wait for the compressor to catch up/shut off, then hit the gun. Does your compressor have the adjustable airflow on the outlet side, turn it to 90 or so.

You gonna need a bigger tank, you are nowhere near the required volume and sustained pressure required to operate that air tool. Have fun when you do get it together though. Ferdi aka Fred

You'll be wasting your money buying a bigger hose. If you have a big need for using the impact, buy a minimum 27 gallon tank compressor. This will run it for a while, but you'll have to let the air build back up if you are using it a lot. What you are actually looking for is something in the neighborhood of 60 gallons and a minimum of 7.5 hp. Get ready to spend at least 1k new.

You might be interested looking into an electric impact. Great for changing tires, blades, lag bolts, etc.

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Originally Posted by Crappie Reaper

You'll be wasting your money buying a bigger hose. If you have a big need for using the impact, buy a minimum 27 gallon tank compressor. This will run it for a while, but you'll have to let the air build back up if you are using it a lot. What you are actually looking for is something in the neighborhood of 60 gallons and a minimum of 7.5 hp. Get ready to spend at least 1k new.

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Well, that depends on whether you're trying to set up shop, or just trying to break the occasional stuck bolt loose. For shade tree mechanics just trying to get by or do a timing belt change, a smaller compressor might work fine.. Not a 3 gallon one though, and 1/4 hose won't cut it either.

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Originally Posted by Crappie Reaper

You might be interested looking into an electric impact. Great for changing tires, blades, lag bolts, etc.

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I second that! Electrics are a good way to go if you don't have a compressor and want to save a few dollars, but still need to get stuff done quick. Perfect for junkyard work, too. Probably best value for the middle weight class in cordless elec would be Milwaukee's M18 series, rated right around 500lb/ft for $300-350 for the set with two batts & charger, or $200 for the tool alone. I can't tell you how handy that thing is to toss in the back seat and, with that and a 3 ton trolley jack, do your best nascar impression for someone stuck on the side of the road. :biggrin

Only thing I can say though is every now and then I need more than 500lb/ft! Tried using a Harbor Freight 3/4" air impact with two tanks hooked up to a T connector, but between the adapter (for using a 1/2 socket) and the worn out 19mm socket, I think it was wasting itself on the rattling. Really didn't want to invest in those 3/4" sockets.. Or, possible the gun itself might just plain be defective? Gonna have to rethink my strategy. What you guys think? Will I be able to get at least a good 700lb/ft blast for less than $300, total, air compressor and all? These Honda bolts are no joke! I'll report back in a day or two when I try something different.

EDIT: I wasn't real clear in that last paragraph. I'm working on one of Honda's crazy counter clockwise engines, and their crankshaft bolts are beasts. It's the only thing (so far) I've encountered that the Milwaukee cordless can't touch, so I thought I'd bite the bullet and invest in an air impact, because the next step up in electrics is probably gonna cost around $800 or so, which is not going to happen in a million years. I'm going to try another HF air impact though, it's possible I just got a bad one. Supposed to be rated at 950lb/ft (probably exaggerated.)

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Originally Posted by BlueBloodedJayBird

Supposed to be rated at 950lb/ft (probably exaggerated.)

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Dang! Welcome to C.C JayBird!

98 HONDA Civic crankshaft bolt - YouTube
(EDIT: forgot to mention, this is not me, this was a video I ran across when I was running a search on 1200lb/ft impacts. Boy I'm glad I saw this so I didn't go buy one!)


Well, two tanks of air (for making sure CFM is high enough) running a 900lb/ft wrench didn't work. I was about to up the ante to a 1200lb/ft impact running off of three tanks, but I'm glad I saw this first, and I read several similar stories in other places about these things just not being possible to budge with ANY impact. I'm not sure which I feel more, that I'm stupid, or that HONDA is stupid. What in the heck are they thinking?

*sigh*

I'd heard about the 5ft breaker bars and whatnot, but I thought that sounded "iffy" and very shadetree. I was trying to get a little more profesional setup.. But now I just have uneccessary junk. Thanks Honda! I just hope this post helps someone who might be searching the internet like I was for advice. GET THE FIVE FOOT BREAKER BAR SETUP.

Just for anyone's curiousity, here was the setup I had. 3/4" Impact gun, 900lb/ft ($80 Harbor Freight) 2HP compressor on 8gal tank ($120) 11gal auxillary air tank ($35) two 12ft 3/8" rubber air lines that run from both tanks ($9 each) 3/8 galvanized water pipe, T fitting (screws directly into gun, 3/8 quick adaptors only on both inputs for maximum flow) reducers for both inputs on "T", filter, teflon tape (about $30 total)

The only thing I didn't purchase that would have helped this setup and who knows, might have made the difference to work, is I didn't use a 3/4" socket but a 1/2" with a reducer. That does reduce torque. It would have cost $18 from NAPA if I had ordered it.

So, to answer my previous question, yes, you can definitely get a powerful setup for $300. The bad news is, it doesn't matter if you have a Honda! banghead

I have used a compact construction compressor for shade tree mechanics for the past 12 years. It powers my air grinder and 1/2" impact gun. I can run out of air quick, however if your not in a hurry, it works great. For the past 8 years I maintained a fleet of 6-8 vehicles. I do everything from oil changes to transmission rebuilds. In fact next weekend I am replacing the rear shackles and shackle mounts on a Ford Ranger. I'll use the impact gun to remove the bed bolts and the spring to shackle bolts.

I gave up on the air grinder, took too long. Air pressure would drop in about 30 seconds, then wait 30 seconds before running again. Seemed like it took forever to grind off bolts. I bought an HF electric grinder, works great.

I bought my construction compresor for $10 for the original owner, a contractor who used it for framing, roofing, and trim work. Now it sits under my work bench and powers my torque wrench and air hose (cleaning and filling tires). Do I wish I have a bigger compressor, you bet, what man doesn't want bigger tools. Do I need it, sure on some days, however my compact has worked well for the past 12 years. I already own its replacement. Buddy of mine bought one of those Air trim kits that comes with the several nail guns and the compressor. He gave me the compressor, it stopped reaching maz pressure and would run constantly. Pulled it apart, had to replace the piston seal, $20 later I have a new compressor.

Will I ever buy a bigger compressor, doubt it. Next air tool will be a spray gun for the bathroom and kitchen cabinets Ill be building within the next couple of years. Tired of useing a brush to stain and polyurathane my wood projects. Took forever to stain and poly all teh windows in teh house. I replaced them several years ago, not replacement windows, new construction, and they are all wood interior with aluminum exterior. The 8' bay window was a couple grand. Sorry, I digress. You can use a pancake compressor with your air gun, just realize you may have to wait for the compressor to build back up to pressure once in a while.

One thing people don't realize is every piece of hardware between the gun and the socket reduces the amount of torque being applied to the nut/bolt. Best to attach the socket to the gun, you'll get maximum torque that way. By the way, my gun pushes about 675 ft pounds of torque and works great. It has enough torque to twist small/midsized car lug nuts in half. IF you use anti-sieze, use it between the hub face and rotor face, never put anti-sieze on your lug studs. The rust bond is between the hub face and rotor face, not the lug nuts and studs.