Air Compressor / Impact Gun advice

[JSM]

I want to buy a decent impact wrench but I am realizing my compressor is not that great. I have a 5hp 26 gallon tank rated at 6.6 SCFM@40PSI and 5.8 SCFM@90 PSI.

 

If I run a length of 30’ 3/8†hose from my tank to another portable tank, 15 gallon or so and then a very short 3/8†hose or bigger to the new gun, would I increase the potential CFM directly to the gun?

 

This is for the home garage obviously. I just want to create the best “oomph†for occasional high torque demand, without going out and buying a new compressor.

[johnc]

What you have should be fine to run an impact gun in a home garage. Its not like you have 16 wheels to remove in the next 5 minutes.

[wfritts911]

Impacts don't need much CFM if you are just using it of and on(like not removing 16 wheels in 5 minutes). You should be fine with what you have. As far as impact guns go, I like the Ingersoll Rand guns, and you can find some one ebay for a decent price.

 

-Will

[JSM]

Thanks John.

 

When I was speaking yesterday to Ingresroll-Rand about this gun, they said my compressor would be under powered:

http://www.ingersollrandproducts.com/am-en/products/tools/impactools/maintenance-automotive-impactools/1-2-drive/2135timax-series/2135timax-series-impactools

 

So I'm realistically looking at getting this one, but still think I'm underpowered to handle it as well:

http://www.ingersollrandproducts.com/am-en/products/tools/impactools/maintenance-automotive-impactools/1-2-drive/231-series

[JSM]

For full torque capacity 24 CFM is needed. Avg CFM is only 5. Seems I never run across an average nut or bolt when I'm trying to get something stuck off!

 

http://www.grainger.com/Grainger/wwg/search.shtml?searchQuery=INGERSOLL-RAND+2135TiMAX&op=search&Ntt=INGERSOLL-RAND+2135TiMAX&N=0&GlobalSearch=true&sst=subset

Item Pneumatic Impact Wrench

Type General Duty

Style Pistol Grip

Anvil Standard

Square Drive Size (In.) 1/2

Torque Range (Ft.-Lb.) 50 to 550

Max. Torque (Ft.-Lb.) 780

Average CFM @ 15 Second Run Time 5.0

CFM @ Full Load 24.0

Max. Bolt Capacity (In.) 9/16

Free Speed (RPM) 9800

Retainer Type Ring

Required Pressure (PSI) 90

Air Inlet (In.) 1/4

Min. Hose (In.) 3/8

Overall Length (In.) 7-1/3

Handle Material Composite

Handle Pistol

Housing Titanium Hammer Case

Weight (Lbs.) 3.9

[randy 77zt]

Best impact gun is an IR244.Old school heavy but very high torque.

 

 

[RebekahsZ]

I have 2 impact wrenches. The larger is a 450# Ingersol Rand. Neither impact wrench works worth a crap. Neither does my cut-off wheel. I assume I am limited by my aircompressor. Turning up pressure hasn't helped. This winter: gas-MIG welder; next year: BIG ASS aircompressor.

Edited June 1, 2012 by RebekahsZ

[calvin280zxt]

that setup is perfectly fine

[beermanpete]

For short bursts the tank supplies the air, not the pump. Use 1/2" hose to get the air flow rate up if you need more power. If you really need power get a 2 stage pump and run the impact with 150 PSI. Single stage compressors only pump up to about 100 PSI.

[(goldfish)]

 

Average CFM @ 15 Second Run Time 5.0

CFM @ Full Load 24.0

 

 

I miss read that the first time across. Should read like this. As in what volume it will use in a given time, not really what size compressor it needs.

 

CFM @ 15 Second Run Time

Average 5.0 CFM

Full Load 24.0 CFM

 

For a couple of bolts with a pause in between I think you should be fine.

[Tony D]

To answer your question, NO.

 

What your spare tank will do for you is give you capacitance. That means your pressure will hold slightly longer before it begins to decay.

 

Beermanpete is correct: most people undersize their supply hoses and strangle the pneumatic tool. Impacts especially.

 

What you want to do it keep your compressor tank at a high pressure, regulated down at point of use. Unfortunately it sounds like you have a 'home' compressor unit full of advertising but not big on truth in actual practice.

 

Look for an older 5 to 7HP industrial reciprocating compressor in the classifieds or Craigslist.a 150-175psig IR 30T, Bendix, Kellog American, Quincy QRD, stuff like that. Don't worry if it's three phase---you can always change to a single phase motor. It will operate at slow speed, be pressure oil lubricated, and last forever. You can get them for a song, even with a new motor. Compared to the $1200 you would spend for a new IR or other compressor.

 

With the higher pressure in the tank, you can effectively regulate down to near your point of use to the needed pressure. It should be a big regulator, and use a 1/2" or 3/4" hose from there to your current 26 gallon tank where you store at 100psi, and use at 90psi. The higher pressure won't decay as fast, and the little tank gives you the capacitance you need for impulse demands.

 

When I poured my driveway, I laid a 1/2" 0.035" wall stainless steel tube through the slab. Runs from my compressor right up next to the roadway inside my fence. Comes in handy with all the kids in the neighborhood being able to fill tires when I'm not around. Nobody's stolen the chuck yet. But since I started turning off my compressor when I leave, they do come by and remind me 'there is a problem'!

 

I like the I-R Titanium Series Impacts. Lots of marketing there, but for a WORK gun it's hard to beat. Light and powerful, but not cheap.

[JSM]

 

This is my compressor. It will run up to 135 PSI. From a CFM rating where is the bottle neck at in compressors? I'm assuming it is the regulator?

 

So best bang for the buck is simply get a shorter 1/2" hose direct to the gun correct? One thing that confussed me was IR told me to run a shorter hose with a weak compressor?

Edited June 2, 2012 by JSM

[kiwi303]

Shorter hose does the same as a shorter muffler. Less loss due to Boyles Law...

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

And no, the law has nothing to do with a dumpy british housewife...

[Tony D]

Biggest bottleneck is line size, and reserve capacity (tank size)...

Most of this is due to not using a regulator. Using air at full tank pressure sucks it down quickly.

Regulating, if done, usually is through a dinky regulator totally inappropriate for something with usage requirements of a 1/2" Impact.

 

As stated, the shorter the hose, the lower the losses. But it doesn't make sense to run a 3/8" hose from receiver to receiver and a 1/2" hose from point of use receiver to tool. You will quickly suck down the point of use tank, and then have a restriction in the transfer hose.

 

I have an 80 gallon tank, hooked by a 1" line to a larger (300 gallon) tank simultaneously branched at a water trap to a 3/4" copper distribution system. All tanks, copper, and stainless lines operate at 125psi, the air is regulated at Point of Use.

 

If I did it over, I wouldn't link distribution concurrently with the tank. It would go from Small Receiver to large receiver, then regulate to 100 psi for distribution with a LARGE regulator, and to tool use (35, 45, 75, 90) at Point of Use. The lower you run your air distribution network, the less you loose from leaks. It's easy to seal tanks. I routinely pump up and then shut ball valves to the large tank to keep it full virtually forever.

 

 

Many people mistake the need for a 'larger' compressor because they don't have a big enough tank. There is a rule that says the bigger the tank you have, the smaller compressor you will need. You have to look at what your AVERAGE and not IMPULSE use is when sizing the compressor. You size the COMPRESSOR on AVERAGE USE. You size the TANK to the IMPULSE USE. The substitute for tank size is storing it at higher pressures (think scuba tank and what size an 80CF'er is!)

 

For instance, in a can plant, they may have an 800HP compressor for each line and a 3400 gallon tank. In reality, when you look at the load cycling you can see it's the inrush that draws down their dinky tank when they start a line. If you put in a 10,000 gallon tank, suddenly a 600HP compressor works JUST FINE with no variations in line pressure. Now you can turn the storage pressure down from 125 to 90 psi because you no longer have a 15psi+ swing in pressure. More like 3-5psi during impulse loading.

 

The result? The 800 HP compressor ran at 80 Amps of 4160, the 600 at 60 amps. Turning down the pressure from 125 to 90 against an 85 psi 'drop dead' requirement saved another 10 amps... well that's 30 amps at $3,450 per amp, per month....

 

Suddenly the cost of that new $125,000 compressor doesn't seem so bad when you pay for it in a couple of months, and after that it's all profit baby!

 

And that, is how I pay for my bills!

[Tony D]

FYI: It takes FOREVER for my little 1HP Speedaire on the 30 gallon tank to fill the big tank (300 gallon) to 125psi.

But I have a digital pressure switch that I can set cut in and cut out by the 0.1psig.

So by running a 5 psi differential, I can run most ANYTHING at my place all day long with the 1HP compressor given the tank size and pressure drop. The tank takes forever to pump up, but once up, and with a 5psi differential it will pump that in about 10 minutes run time with LOOOOOONG pauses in between.

 

A 300 gallon tank is around 50 Cubic Feet (remember the SCUBA Tank size, which is 80 CF, but at 3000psi--more pressure, smaller tank.)---two stage regulation is common in SCUBA, and industrial systems.

 

My 7HP pumps the Tank up in considerably less time, so if the kids have sucked the big tank down over a weekend.... I'll usually pump up with the 7HP then swap over to the 1HP Speedaire for what I need. The only time I really 'need' the 7HP is when I'm heavily using my grinders and spraying a big car. Or using the large nozzles on my sandblaster.

 

In that case, I hook up the Diesel and just run it to the big tanks (in tandem for 600 gallons capacity...)

 

 

 

Yeah, having a big truck and access to customers saying "can you get rid of this for me?" comes in handy sometimes! Yes, I have a diesel compressor--I am diseased!

[kiwi303]

But remember the high pressure rating on the Scuba tanks requires more strenuous checks, if a full 80CF goes out, that is the same power as two hand grenades. A Larger, lower pressure tank may knock you off your feet if it goes, but it's much less likely to kill you.

 

 

On the other hand, maintained steel 72's are nearly indestructable, much to be preferred over Ali 80's which have a finite working life due to brittleness from expansion and contraction.

Edited June 3, 2012 by kiwi303

[JSM]

Thanks Tony for the explanation. I always feel dumb after I read through all that has been said in many posts and then realize the importance of math in everything I read!

[Tony D]

It was a dramatic example of what happens with pressure: 160CF you can carry on your back, or a tank that is 1M Diameter X 2.6 M Tall or thereabouts for HALF the capacity.

 

Always get a 175 psi industrial compressor with a 80 or 120 gallon tank. Realistically the CF you actually physically can store is more than the dry calculated volume due to the higher pressure. Running your X sized tank at 100psi or running it at 125psi... Ends up being 25% more storage capacitance. And that means more time between cycles. More time between stopping your DA to recharge...

 

I have two different 30 gallon tanks on wheels that I use identically as JSM described--make myself a "Luftzow"--fed with 1/2" or 3/4" 400psi rated Goodyear Gorilla Hose, I have a multiple QD Connector 'tree' on each one, so I have several tools hooked up at one time. Because I'm too lazy to run the same tool on the same hose... and because my blue hoses are oil free, and they don't go on the oil flooded tank!

[rejracer]

I've run my impacts on 5 hp and 2hp 30 gallon compressors. As was stated before, get good plumbing, it makes all the difference in the world. The only tool I have a problem with is the die grinder.

 

As far as an impact gun I am using the craftsman branded ingersol Rand unit. It is rated at 600ft-lbs if I recall correctly. I've found that I use far LESS air using a good gun than with the other far cheaper and less powerful impacts. My cheaper craftsman gun is virtually useless. It's good for taking off wheels, but honestly anything where there is more than 100lbs or so it's just not worth even trying. I pull it out once a year or so to oil it up and get minimal use on it but other than that it stays in the drawer.

 

Another trick in increase the torque output is use short impact sockets. As slight as it may be, the deep well sockets dampen the impact in that they act as a spring. Far more than a deep well socket an extension really reduces the effective torque. An 8" impact extension feels like it reduces the effective torque by 50%. Before you start buying the expensive stuff, make sure your using the best of what you already have correctly.

 

As far as Scuba tanks go, you can put a

and they will not explode. But be turned into a rocket pack they certainly will be. I would not bet my life on the scuba tank not exploding, but it shows how a properly designed and inspected tank being run within it's design parameters handles a breach. On air compressor tanks watch out for rust or physical damage that may compromise the strength of the tank if you go for a used unit.

[JSM]

As far as an impact gun I am using the craftsman branded ingersol Rand unit. It is rated at 600ft-lbs if I recall correctly. I've found that I use far LESS air using a good gun than with the other far cheaper and less powerful impacts. My cheaper craftsman gun is virtually useless. It's good for taking off wheels, but honestly anything where there is more than 100lbs or so it's just not worth even trying. I pull it out once a year or so to oil it up and get minimal use on it but other than that it stays in the drawer.

 

 

So are you happy with the craftsman branded ingersol Rand unit? I saw them the other day at Sears.