Another help me choose an air compressor thread

[Bcom]

For the longest time now ive dealt with the small air compressors ive always had to run an impact or other air tools ive had. Help me choose another used/new air compressor please

My needs are simplistic. I have a one car garage that i also use as my shop. I have one hose reel with a 1/2" hose in it that can reach easily throughout my garage. I need an air compressor that can run a 600ft lb impact as well as some other air tools if i ever need to. Right now i have 110v 4hp 25gal Craftsman that barely gets me by to run an impact but i dont believe its allowing my impact ro reach its full potential.

What do i need to get my full benefit of my impact and run any air tool i need. Like die grinders and sanders? 220v is available in my garage but ill have to change the area that the 220v plugin is located in my garage. What size air compressor will get me by without being overkill? It has to be a vertical unit since floorspace is not adequate for a horizontal. Any help or suggestions?
Thanks

 

[md21722]

Die grinders and sanders means you need at least a true 5 HP, dual stage air compressor 80 gallon tank. CFM should be at least 17. If you run powerful die grinders like 0.5 HP or more, you will probably want to get a 7.5 HP air compressor. Also true if you are going to be sand blasting. And go bigger if you want. In North Central Ohio I bet you can find a decent used one on craigslist. But, to your first part, with the impact wrench. I have had good luck using an impact on a 2 HP 26 gallon single air compressor. I run it on a short 3/8" hose with the cut in at least 105 PSI and the regulator set about the same. The regulator needs to be set so the tool sees 90 PSI when running. If you set the regulator to 90, I'm sure your impact is seeing less.

 

[Bcom]

Yes there are decent 60 gallons on CL for 250-350 dollars. An 80 gallon seems to be overkill dont you think? I may be wrong. I really want my impact to be able to reach it full potential. Right now i dont own any air sanders but if i ever wanted to get one,id like to not have to worry about air delivery. Ive only got one 600ftlb impact and one 60ftlb ratchet.

 

[brownbagg]

just go to lowes or home depot and buy a big one. except for the high dollar model like snap on, they are basically the same.

 

[dashunde]

I've had great luck with this one... 60gal Vertical
https://www.lowes.com/pd/Kobalt-3-7...al-Stationary-Electric-Air-Compressor/3370356

I like it a lot and would buy it again. Partially because Lowes is fantastic, they'll stand behind a product even if a stingy warranty-weasel manufacturer refuses.

It probably wont keep up with non-stop sanding/grinding, but neither will you and its $500 instead of $1500+, its not huge or super heavy, seems to be decent quality all-around and its really hard to beat for the money for use in a above-average homeowner shop.
I adjusted mine to 150 psi.. it tops that off quickly enough, isn't too hard on the pump, and gives a little headroom before the 120psi kick-on.

I left mine on its pallet.. my garage floor has plenty of slope, the pallet absorbs a bit of vibration (vs hammering away on the concrete) and it doesn't "walk" down the slope at all.
I removed two of the bottom boards so it sits level, repositioned the tank feet and bolted securely.

Be sure to use the correct oil in any compressor you buy, change it yearly, clean/replace the air filter, drain the water out of the bottom now and then and be prepared to change out the petcock/drain at the bottom eventually (no big deal).

 

[Infinia]

What do i need to get my full benefit of my impact and run any air tool i need. Like die grinders and sanders

Continuous operation of these tools puts you into very stout compressor territory indeed.
Running high air surge off and on is one thing, consider electric tools for most economical solutions.

 

[Infinia]

I adjusted mine to 150 psi.. it tops that off quickly enough, isn't too hard on the pump, and gives a little headroom before the 120psi kick-on.

This is very wise, most homeowner compressors sporting 125 / 90 psi cut-in are doomed from the start! Perhaps that's why the OP is running with silly large 1/2" hose (air line losses at high air surge ) Then its just a matter of matching max duty cycle ratings to your uses.

 

[md21722]

Yes there are decent 60 gallons on CL for 250-350 dollars. An 80 gallon seems to be overkill dont you think? I may be wrong. I really want my impact to be able to reach it full potential. Right now i dont own any air sanders but if i ever wanted to get one,id like to not have to worry about air delivery. Ive only got one 600ftlb impact and one 60ftlb ratchet.

You don't need any more than you have for impact use unless you don't want the compressor to run a bunch. If there is a power issue then something is not working correctly. Either your line pressure is low or the gun itself is weak.

Rotary air tools use enormous amounts of air. I'm talking grinders, sanders, ratchets, and drills... If the tool advertises 3-5 CFM you've got to multiple that out 4-5X to get its real usage. CFM is an industry rating that does not tell you what kind of air compressor you need directly.

Impacts use air, but not as much as rotary in general because you typically aren't holding the trigger for as long. It a burst type of thing.

Whether or not that Lowe's unit dashunde is referring too will be of any use to you depends on how long you are going to run sanders or die grinders. Most sanders are around 15 SCFM, die grinders are generally between 12-25 SCFM, drills are often 25-30 SCFM. Percussive tools like air hammers and air saws are generally around 10-11 SCFM.

A 3.x HP 60 gallon air compressor is not going to keep up if you want to use the die grinder for any length of time. Assuming your average IR die grinder, a 3.x HP air compressor which cycles 120-150 PSI, and you start running the die grinder with tank at 150 PSI, the compressor will come on after 45 seconds, and you will start to feel your tool lose power after another 30 seconds. If you shop around and find a die grinder that is more efficient, around 12 SCFM you will get much longer run times. The IR uses about 22 SCFM IIRC. On the sander, you would be able to use it for about 2.5 minutes before it starts losing power.

 

[Bcom]

I tried to run a 3/8 hose to my impact but it took too much power away from it. The 1/2 hose provided an extra bit of power.

 

[md21722]

I tried to run a 3/8 hose to my impact but it took too much power away from it. The 1/2 hose provided an extra bit of power.

What is your regulator set at? At what pressures does your compressor cut in and cut out?

 

[Bcom]

I have the regulator maxed at full pressure which i think is 125psi. Not sure when the pump kicks on and off. It does seem to lose alot of pressure before it kicks back on again. I might look into the 60gal Kobalt if i cant find a decent used one.

 

[JJThrasher]

I have a thread going right now about my air compressor. Its the 60 gallon Kobalt. It'll do a 1/2" impact fine, but I easily outrun it with a die grinder or drill. I'm currently considering upgrading or buying a second and running two.

 

[Bcom]

I just found this compressor. One reviewr said its the same as the kobalt but cheaper
http://www.ruralking.com/industrial...ationary-air-compressor-135-psi-c3706056.html

 

[Infinia]

^135 psi is only 10 more than yer old 125, still too low. IMO 150 or 160 would be better, higher pressure means more air at the tools operating pressure level E.g tank appears bigger! also allows higher cut-in,. So you can easily run more manageable 3/8 hose & sell off the 1/2.

 

[Bcom]

^135 psi is only 10 more than yer old 125, still too low. IMO 150 or 160 would be better, higher pressure means more air at the tools operating pressure level E.g tank appears bigger! also allows higher cut-in,. So you can easily run more manageable 3/8 hose & sell off the 1/2.

Good point. Ill look more into the kobalt then that has 155psi

 

[WhiskeyRanger]

I've had great luck with this one... 60gal Vertical
https://www.lowes.com/pd/Kobalt-3-7...al-Stationary-Electric-Air-Compressor/3370356

I like it a lot and would buy it again. Partially because Lowes is fantastic, they'll stand behind a product even if a stingy warranty-weasel manufacturer refuses.

It probably wont keep up with non-stop sanding/grinding, but neither will you and its $500 instead of $1500+, its not huge or super heavy, seems to be decent quality all-around and its really hard to beat for the money for use in a above-average homeowner shop.
I adjusted mine to 150 psi.. it tops that off quickly enough, isn't too hard on the pump, and gives a little headroom before the 120psi kick-on.

I left mine on its pallet.. my garage floor has plenty of slope, the pallet absorbs a bit of vibration (vs hammering away on the concrete) and it doesn't "walk" down the slope at all.
I removed two of the bottom boards so it sits level, repositioned the tank feet and bolted securely.

Be sure to use the correct oil in any compressor you buy, change it yearly, clean/replace the air filter, drain the water out of the bottom now and then and be prepared to change out the petcock/drain at the bottom eventually (no big deal).

I was considering that compressor, but I'm afraid I will still have compressor envy after seeing my friend's IR 80 gallon. I guess "seeing" is the wrong word... I have no problem with my little 25 gallon, but it's so damn loud. That IR is very quiet and that's what got my attention.

How loud is that compressor? I'm in a nice quiet sub and hate running my current compressor due to the noise.

 

[md21722]

I was considering that compressor, but I'm afraid I will still have compressor envy after seeing my friend's IR 80 gallon. I guess "seeing" is the wrong word... I have no problem with my little 25 gallon, but it's so damn loud. That IR is very quiet and that's what got my attention.

How loud is that compressor? I'm in a nice quiet sub and hate running my current compressor due to the noise.

These compressors are pretty noisy.

I had a Husky version some years ago. My neighbor had one too. Our garages were probably 125 feet apart and we could always here each others if we were outside.

The other problem with single stage pumps is that they "slow down" as pressure builds. After about 110 PSI output drops significantly. I saw an add where they clocked the standard Husky 60 gallon. 0-120 6m 34s, 0-145 8m 48s. So you can see it took 2m 14s to build the last 25 PSI. This was in Colorado where air compressors are downrated for altitude about 25% but the effect is the same at lower altitudes as well. Dual stage air compressors like that IR are generally only quoted at 175 PSI and pump pretty linearly throughout the pressure range.

 

[md21722]

I have the regulator maxed at full pressure which i think is 125psi. Not sure when the pump kicks on and off. It does seem to lose alot of pressure before it kicks back on again. I might look into the 60gal Kobalt if i cant find a decent used one.

Have you inspected the gun for problems? Is the intake screen, if present, clean? Some guns are just junk. A 2 HP 25 gallon compressor with a 25' 3/8" hose ran my NAPA gun just fine. It was far superior to the $99 pancake with tool kit my neighbor has.

 

[WhiskeyRanger]

These compressors are pretty noisy.

I had a Husky version some years ago. My neighbor had one too. Our garages were probably 125 feet apart and we could always here each others if we were outside.

The other problem with single stage pumps is that they "slow down" as pressure builds. After about 110 PSI output drops significantly. I saw an add where they clocked the standard Husky 60 gallon. 0-120 6m 34s, 0-145 8m 48s. So you can see it took 2m 14s to build the last 25 PSI. This was in Colorado where air compressors are downrated for altitude about 25% but the effect is the same at lower altitudes as well. Dual stage air compressors like that IR are generally only quoted at 175 PSI and pump pretty linearly throughout the pressure range.

Good info. The noise is really my biggest issue. I rarely run rotary air tools for extended amounts of time, but that may change if I can get something that won't wake the whole neighborhood up every time it cycles. I really wish manufacturers would list standardized noise levels.

 

[md21722]

You already know what the IR sound like, here is another video for a Champion R15 pump. It runs at 734 RPM. I have 2 of these in my garage and get no complaints. I like the Champions for a number of reasons. They've been making them forever, they aren't that noisy, easy service on the valves using a 9/16" wrench, and no gaskets to blow because the cylinder body is one piece. Go to 1:15 for it running:

This one is a Champion Centurion series which is a more conventional design with head gaskets and reed valves:

He's running it 3 phase off a VFD, but you get the idea of the noise.

 

[dashunde]

My needs are simplistic. I have a one car garage that i also use as my shop. I have one hose reel with a 1/2" hose in it that can reach easily throughout my garage. I need an air compressor that can run a 600ft lb impact as well as some other air tools if i ever need to. Right now i have 110v 4hp 25gal Craftsman that barely gets me by to run an impact but i dont believe its allowing my impact ro reach its full potential.

What do i need to get my full benefit of my impact and run any air tool i need. Like die grinders and sanders? It has to be a vertical unit since floorspace is not adequate for a horizontal.
Thanks

I read back through, and have a few more thoughts..
Any quality 60 gallon starting at 150psi will be a night and day difference over a 110v 25 gallon at 125psi, simply because the 25psi increase combined with the additional 35 gallons combines for a exponential increase of available air before either kick on.
Really, its a huge difference, one that sustains more pressure longer, and your impact will surely take notice.
I dont know what you are using that impact on, but if you kick on a 60 gallon 150psi compressor with it one of two things is happening... you are running lots of very tight nuts/bolts, or your banging your head against the wall and need a torch instead of a new compressor.

Die grinders & Sanders... yep, running those for a long time will required a 80 gallon 3-stage compressor. Particularly if you have more than one guy at work. But what homeowner really runs a die grinder that long, and on what?

I had a IR 80gal 3-stage running at 190psi... it was huge, loud, and hard on tools, airlines and fittings. Plus it cost a small fortune.
When I moved it stayed behind.

Pick a nice nice 60 gallon 2-stage with a good reputation, cast iron compressor and a decent motor.
No, your not going to run a 3 man mechanical or 1 man body shop off of it, but your also not spending silly money for a capability you'll rarely, if ever need.

fwiw... I regularly rotate my Tundra and Rav4 tires, I'm not positive, but I dont think my 60gal Kobalt kicks on at all. Lug nuts are only supposed to be ~100-150ftlb anyway (hand torque to prevent rotor warp) and it takes about 1 second per nut to remove them.

 

[Bcom]

Im using a craftsman pro 1/2 impact. Model 19905. It in good shape and well cared for and oiled after every use.

 

[md21722]

I had considered the gun to be the problem, but as dashunde asks, what are you trying to remove? Are we talking lug nuts or old tractor bolts that have been rusted in place for the past 50 years? I have not used the Cman impact, but I had a NAPA one with similar specs and it worked fine with a compressor the size you have. I used it with normal I/M fittings on a 25' hose. At 50 foot you're about right to have the regulator set at max. How does it do without the regulator at all? You would need a bigger compressor for die grinders and sanders, but what you have should be fine for an impact buzzing on cars or light trucks. If it doesn't, you might need a more powerful 1/2" impact, or move up to 3/4" - 1" drive. Something like the Snap On MG725 or IR2235 put out a lot more power than your Craftsman.

 

[Citation]

I'm going to second the thought that you may have an issue that's not related to the compressor. Using the ~500 ftlb IR 1/2" gun I pulled the 32mm axle nut off my old car. My compressor was a 4 gallon 4cfm twin tank contractor type. Yes, it took the first tank to break the nut but the fact is the small compressor was enough to do the job with patience. A bigger compressor would do things faster. Thing is if you have minimal loses between the 120psi tank and the gun then you should have enough air if only for shorter runs. You might look at getting a higher flow regulator because honesty if all its working the current compressor should be sufficient.

 

[skipnay]

Going to keep watching this air compressor thread. Why? Because I can and I'm in the same boat...

 

[Infinia]

IDK why folks are so wrapped up about compressor sound levels. IMO they are all loud!
The expensive so called "quiet ones" use 2 stages along with lower RPM and bigger displacement , theyre not noise free either, but they can cost 4 times as much, just to meet same SCFM of a lower duty cycle high RPM screamer. In my way of thinking the loudest thing is probably an air ratchet operating 2 feet away. It's Loud and Louder folks no way around it.
I'd be thinking about ditching some these old school air tools. Sure we still need air for many things but SCFM continuous duty and quiet is budget unfriendly. Pick your poison.

 

[Infinia]

. I used it with normal I/M fittings on a 25' hose. At 50 foot you're about right to have the regulator set at max. How does it do without the regulator at all?.

The problem is not at max but at min pressure say nearer to the 90 psi cut-in. Re Adjust it to 100 psi you still only have 10 psi line pressure drop to work the gun at it's so called rated torques. So even a 1/2" monster air hose straight in wont work right, at the low end of the tanks pressure. Its real easy to see, invest in a cheap pressure gauge and mount one at both ends of the hose and run some tests on various torques on 4 or wheel lug nuts. You don't need an absolute accurate gauge either, you watch for the differences in line pressures.

 

[md21722]

The problem is not at max but at min pressure say nearer to the 90 psi cut-in. Re Adjust it to 100 psi you still only have 10 psi line pressure drop to work the gun at it's so called rated torques. So even a 1/2" monster air hose straight in wont work right, at the low end of the tanks pressure. Its real easy to see, invest in a cheap pressure gauge and mount one at both ends of the hose and run some tests on various torques on 4 or wheel lug nuts. You don't need an absolute accurate gauge either, you watch for the differences in line pressures.

I have all that and run 2 Champion 5HP R15 pumps on 240 gallons today. It's great.

 

[Bcom]

After testing my impact on another industrial compressor,it appears my impact may be the culprit. The impact is suppose to be 600ft lb in reverse and 450ft lb forward. Can a 4hp 125psi 25gal be able to push this impact effectively?

 

[dashunde]

Can a 4hp 125psi 25gal be able to push this impact effectively?

For the first few seconds (10-20?) the tank volume doesn't matter so much, instead it's pressure and volume running through the line that makes the difference. The smaller tank just means pressure won't be sustained very long and tool power of course follows that decline.

Yes, 125psi should be effective, but it won't be as effective as 150psi (obviously).
It really comes down to your impacts ratings, how much torque is it supposed to generate at what pressure?
Some are better at doing more with less.
Impacts also aware internally, and become less effective.