Air compressor experiment

[Sticks McGee]

So today on my break I ran home and got my home compressor. I have a truck I need to put some tires on and I figured this might prove to be a good experiment. Here are the details:

Compressor A.
My shop compressor. A large ingersol (80 gallon, two stage running on 460 v)
This compressor is set at shut off to have 160 psi. I used my hose reel that is attached fairly close to it. The hose reel is probably about 15 years old and it is 3/8" hose and it is 150' long. I drained the compressor down a bit and let it run to cut off.

Compressor B.
Craftsman oiless 33 gal compressor. It's rated at 1.6 hp and 5.1 cfm at 90 psi.
I did a modification to it where I put a T fitting right near the outlet. The outlet on this is 1/4" NPT. originally the fitting came out to a T. one side of the T was the pop off valve and the other side was stepped down to a tiny hose that ran back up to the regulator manifold, thru the manifold and to the supplied two quick couplers. My modification takes the shortest path I could get right to my quick coupler bypassing the regulator manifold and the regulators. All fittings are 1/4" NPT and my hoses are 3/8" with 1/4" NPT on each end. So in short I have 33 gallons of 150 psi air available to the hose, then to the tool.

Impacts.
My 1/2" IR 2131 and the shops IR 2141 3/4" impact. Each impact has a 30" whip hose attached. Both of these impacts in is excess of 10 years old.

Lugs.
Wheels are 19.5" unilug 33mm nuts. These wheels I always torque with my 3/4" torque wrench to 485 ft.lb

With both compressors fully ramped at 160 psi (shop) and 150 psi (home) I connected the 3/4 impact to the craftsman. I pulled 4 nuts off with no struggle whatsoever and just started on the 5th one when the compressor kicked on. This is a 33 gallon oiless compressor connected to two 50' 3/8" airlines to make 100 ft of line running thru 1/4" NPT fittings running an older 3/4" impact. The lugs have been on a while so I am not sure what the breakaway torque is to break them loose. The 3/4 did not even struggle to spin them off. After the compressor kicked on I switched over to the hose connected to the shop air and did a couple with that. The impact performance was seemingly identical.

My point here is I am not trying to say that an expensive compressor isn't better. I would love to have a 60-80 gal 2 stage myself. I guess my real point is that the average DYI doing brakes on his/her car or truck should not have a problem running a 1/2" impact and getting the lugs off and on. Most people who are DYI at home are not gonna be running an air hungry 3/4" impact and pullng off 33 mm nuts that torque at 485 ft. lb

When I first fired up my home compressor after my wife bought it for me for christmas, the way it was ranning thru the tiny fittings was choking it down to a point where it did not work worth a piss. I also run hi flo fittings on all my stuff and have been doing that for years at work. When I got the compressor at home I decided to use the same fittings.

 

[Sticks McGee]

more pics

 

[ChaseDE]

anything can happen i guess. too many variable to prove anything here.

i am new to using air tools regularly. inherited my grandpa's impacts recently. i have a 20 gallon 150psi oiless craftsman compressor. https://www.craftsman.com/products/craftsman-20-gallon1-5-hp-vertical-air-compressor-150-max-psi

so i pull an old snap-on 1/2 impact out of a drawer, it has been sitting in that drawer at least probably 20 years or more, pop it on my line, and it whizzed off the axle nut on my 2010 acura rdx like it was nothing....i was very impressed, those things can be a pain.

also worked well on my lawn tractors blade nuts which get really tough to turn.

 

[dnschmidt]

You can get away with a small compressor using an impact. The load is sporadic and short lived. Try it with a die grinder or professional spray gun. EPIC FAIL.

 

[Sticks McGee]

OK...I switched to the 1/2" and I was able to get all 8 lugnuts off befoire the compressor kicked back on. Here is where the difference is. I immediately started putting the nuts back on and tightening them. Once I got to the 4th one I could feel the impact losing power. The compressor was running. Not being 2 stage and only 33 gal of air it would not maintain like the shops will. Even with the shop compressor running it still gives me pretty much full power.

There again the point I am making is with a good 1/2" impact and standard 1/4" NPT fittings and 3/8" hose (even 100 ft) the average DYI should be able to get the lugnuts off of his/her car/light truck.

 

[aka Larry]

When I bought mine Husky 60 gallon, I wanted one that didn't have to run 24/7 because of the noise. The smaller oil-less ones are even louder, and run much more often.

I can't find the direct quote, but someone here on GJ said it best when talking about the noise level of an oil-less compressor:

Go to your neighbors back yard, dig a 6-foot deep hole, bury the compressor, go back inside your house, close all the doors, and you'll still hear it running.

 

[Sticks McGee]

You can get away with a small compressor using an impact. The load is sporadic and short lived. Try it with a die grinder or professional spray gun. EPIC FAIL.

Yep..I agree...Again the point I am making is 33 gallons of air with 150 psi should be able to get a good impact to take lugs off with 3/8" hose to the average persons car or light truck. By no means am I saying don't buy a large 2 stage compressor...I myself want to get one eventually.

 

[Sticks McGee]

When I bought mine Husky 60 gallon, I wanted one that didn't have to run 24/7 because of the noise. The smaller oil-less ones are even louder, and run much more often.

I can't find the direct quote, but someone here on GJ said it best when talking about the noise level of an oil-less compressor:

Again...Agree...this thing is loud as hell

 

[Engine]

My point here is I am not trying to say that an expensive compressor isn't better. I would love to have a 60-80 gal 2 stage myself. I guess my real point is that the average DYI doing brakes on his/her car or truck should not have a problem running a 1/2" impact and getting the lugs off and on. Most people who are DYI at home are not gonna be running an air hungry 3/4" impact and pullng off 33 mm nuts that torque at 485 ft. lb

Thanks for posting the demonstration.

Taking it to the extreme, sometimes I'll rotate the tires on a 1/2 ton Dodge using one of those 6 gal. porter cable pancake compressors. Using a 3/8" hose, 50' length, 1/4" connections, and a 1/2" IR 231C impact, it has enough power to easily spin off all the nuts from one wheel. By the time I get to the next wheel, it is ready to go again. Definitely not the ideal setup, nothing fancy or expensive, but it will get you by in a pinch when you don't have access to the larger unit.

 

[Chaznsc]

When I bought mine Husky 60 gallon, I wanted one that didn't have to run 24/7 because of the noise. The smaller oil-less ones are even louder, and run much more often.

I can't find the direct quote, but someone here on GJ said it best when talking about the noise level of an oil-less compressor:

AMEN, I would rather live next door to the airport.

 

[-Brent-]

I had a 20 gallon Campbell Hausfeld, recently, and replaced it with my Quincy QT5 80 gallon. While the 20 gal would bust lug nuts off (anything with 100psi will) it's the air volume, especially while the compressor is running, that will make life easier.

I have worked the CH to the point that there wasn't enough air/pressure to shoot a nail in fully, I haven't yet challenged the 80 gal to that point with an air tool.

 

[Sticks McGee]

Absolutely guys...I agree with everything that's been said...

I work in the shop by myself. I take care of a fleet of 35 trucks day in and day out. First off let me say this: No way in hell could this craftsman compressor keep up with my demands on a daily basis here at work. Most of my fleet is smaller trucks than this one and I use battery impacts 99% of the time but I am not sure this thing could keep up with me airing tires at one station while I am using the tire machine across the shop and on the bigger trucks like this one I would have it up in the air on the rack and need to zip 32 lugnuts off and bounce right to the tire machine (if doing tires) Extended use of a die grinder there is no way...All of these things I know. I wasn't so sure this thing would even run that 3/4" impact let alone thru 100 ft of 3/8" hose.

I was happy that my wife at the time thought about me enough to buy me one but I didn't have the heart to tell her it wasn't anywhere near what I really wanted. If I could not have gotten it to work I wouldn't have had a choice I guess...

 

[Infinia]

There again the point I am making is with a good 1/2" impact and standard 1/4" NPT fittings and 3/8" hose (even 100 ft) the average DYI should be able to get the lugnuts off of his/her car/light truck.

Attach a pressure gauge at the tool ( this gives the total air line losses / pressure differential ) and record the cut-in pressure settings.
sure with tanks 150+ psi is miles ahead of the average DIY 125 psi compressor tanks with 90 psi cut in settings. Most would agree that a mere 25 psi gives much more leeway for line pressure drops, the cut-in pressure is key here between working and not. So @90psi at the tank, the tool will have been out of spec with zero margin for any line pressure drop. The avg DIY with 125psi tanks without any cut-in adjustments is not ideal for real world set-ups.

 

[Sticks McGee]

Attach a pressure gauge at the tool ( this gives the total air line losses / pressure differential ) and record the cut-in pressure settings.
sure with tanks 150+ psi is miles ahead of the average DIY 125 psi compressor tanks with 90 psi cut in settings. Most would agree that a mere 25 psi gives much more leeway for line pressure drops, the cut-in pressure is key here between working and not. So @90psi at the tank, the tool will have been out of spec with zero margin for any line pressure drop. The avg DIY with 125psi tanks without any cut-in adjustments is not ideal for real world set-ups.

I did absolutely nothing to my compressor as far as pressures it cuts in and out at. I ran a direct tap as close to the tank output as I could by installing a T fitting and putting a coupler there. I kept the stock size (1/4" NPT) of that fitting. The only reason I did this was so that I could run an impact at home to remove lug nuts. I still have two couplers that are after the regulator. This is where I connect my Brad nailer.

 

[JJThrasher]

I used to run my half inch impact on a 5 gallon portable 110v compressor. It did it, it just wasn't fun. If I'm filling 2-3 22.5s and trying to run a 1" gun at the same time the small compressor won't cut it. If I wasn't multitasking then a smaller compressor would be fine.

 

[taumac]

I agree. I prefer a 30 gal 150psi compressor for my garage for mobility reasons over a 60 gal. It's a Kobalt compressor from Lowes. If I using a DA or some air hog tool I sometimes have to let it catch up. I've also use my 6 gal 150psi or 8gal 135psi unit with my impact with had to bring it somewhere.