Air Compressors - Overkill or not?

[1995droptopz]

So my Craftsman oil-less 30 gallon is dying a slow death after 20 years of loud, faithful use.

I want to replace it, but keep wrestling with the variables of CFM, noise, size and cost.

My usage consists of mainly my 1/2 impact, sprinkler blow-outs, occasional HVLP air gun use for small jobs, and some die grinder usage.

I originally was looking at the 60 gallon Kobalt 2 stage or Husky single stage, but think it might be overkill currently.

If I do not go that route, I am intrigued by the Kobalt quiet 26 gallon, but at 4.5 SCFM @90, I am concerned it may not drive my tools as well as what I have. Looks like my Craftsman is 6 SCFM @90.

Anyone out there already go through with buying one they regret, or have other helpful advice? Note that I do not use this every day, so it is an occasional use tool, but when I use it I want it to work correctly.

 

[rsanter]

60 gal is a great size for the home shop.
80 would be overkill

 

[bochnak]

Did your current compressor do the job? If so, 2hp 6cfm is all you are going to get at 120V.

This one is pretty quiet:
https://www.harborfreight.com/29-gal-2-hp-150-psi-cast-iron-vertical-air-compressor-61489.html

What is the budget?

Matt

 

[Parrothead]

So my Craftsman oil-less 30 gallon is dying a slow death after 20 years of loud, faithful use.

I want to replace it, but keep wrestling with the variables of CFM, noise, size and cost.

My usage consists of mainly my 1/2 impact, sprinkler blow-outs, occasional HVLP air gun use for small jobs, and some die grinder usage.

I originally was looking at the 60 gallon Kobalt 2 stage or Husky single stage, but think it might be overkill currently.

If I do not go that route, I am intrigued by the Kobalt quiet 26 gallon, but at 4.5 SCFM @90, I am concerned it may not drive my tools as well as what I have. Looks like my Craftsman is 6 SCFM @90.

Anyone out there already go through with buying one they regret, or have other helpful advice? Note that I do not use this every day, so it is an occasional use tool, but when I use it I want it to work correctly.

If you’re using it to paint, get the 60 gallon. If not, get the 26 gallon. Look at the leaps and bounds cordless tools like the impact have improved over the last ten years, and then the 10 years before that. Other than painting and blowing out sprinkler lines, air tools are becoming less and less necessary.

 

[SteveH-CO]

60 gallon upright - oil-type. Quiet, space-efficient, and enough power to sandblast (lightly) and will keep up with impact wrenches and paint guns. No one ever has said 'I have too much compressor....' - really, never!

You can find these used pretty easily, as they aren't on wheels so people don't want to move them to a new house. Lowes and HD sometimes have pretty good deals on new ones.

 

[Davefr]

No one ever has said 'I have too much compressor....' - really, never!

Except for me. I have a 5HP/60 gallon IR Compressor sized for using a Sioux DA sander that consumes 15 CFM at high duty cycle.

I hate using a pneumatic sander. Stiff air hose and deafening noise from the compressor running 100%. I'd much rather sand using electric and by doing so I could get by with a much quieter, portable, dual voltage, 33 gallon/2HP compressor.

My advise is to do as much as you can with Lithium or Electric and then size a compressor for what's left.

 

[1995droptopz]

Did your current compressor do the job? If so, 2hp 6cfm is all you are going to get at 120V.

This one is pretty quiet:
https://www.harborfreight.com/29-gal-2-hp-150-psi-cast-iron-vertical-air-compressor-61489.html

What is the budget?

Matt

Most of the time it worked unless I used my die grinder for more than a quick job. Or when I used my DA sander...ugh looks like I’m talking myself into the big’un

 

[1995droptopz]

If you’re using it to paint, get the 60 gallon. If not, get the 26 gallon. Look at the leaps and bounds cordless tools like the impact have improved over the last ten years, and then the 10 years before that. Other than painting and blowing out sprinkler lines, air tools are becoming less and less necessary.

I have not really gotten into the electric impact game yet, although I keep eyeing them. Still using my trust 20 year old IR 1/2 and 3/8 drive

 

[Torque&Recoil]

Die grinders use a lot of air, and electric die grinders are like 3 times the size of pneumatic. To each his own, but I am in the category of "buy something bigger than you think you need ... because you will need it eventually". I am on my 4th air compressor, each one larger than the last. I would have saved some money if I had just bought a monster originally.

 

[sberry]

This is a place a little overkill is worth it, can meet any potential demand. I like something 2 stage, it doesn't have to be great but 5 hp is standard for body work, a guy would be one and done.

 

[bastage]

When I got mine (to replace a 20 gallon oiless) I looked at everything available & in the end everything ***** or is expensive when your buying new. Buying from craigslist is the way to go I think. I always see good quality 2 stage older compressors going for 400-800 with much more performance & quality then you can find for less then 1500 if your buying new.

 

[Citation]

Any reason not to fix what you have? The rings on the oiless compressors do wear out but are typically quite fixable. There noise levels of older oiless compressors however...

If you are looking at a ~$400 120V compressor, yes, definitely look at a~$500 60 gallon compressor.

Do keep in mind that noise levels have a lot to do with intake filter design. A screw on filter is far more likely to offer the opportunity to reduce noise via intake modifications.

Definitely look for used if you can move it. It's not uncommon to see 5hp, 80 gallon compressors going for $500 or less. It seems like used 60 gallon compressors go for similar money.

Make sure you stop any leaks. It ***** having to fill up an 80 gallon compressor to air up a tire.

 

[dnschmidt]

There is NO SUCH THING AS OVERKILL with respect to air compressors. Might makes right and bigger is better. I have an 80 gallon two stage 5HP Quincy and wish I had a 7.5HP. Saying you have too much compressor is like saying you have too much money or to big of a pecker. Both first world problems for sure.

 

[joshmodelskidoo]

Had the same compressor. I now have a 60 gallon sanborn and no regrets. More air, quiet compared to the craftsman and I find myself using my air tools far more than before. Get a hose reel and about 10ftor more of airline between the compressor and regulator to get the water out. I also put a ball valve on the drain so I don’t have to crawl under it to drain it

 

[joe_padavano]

You can't have too much SCFM, and the more SCFM, the smaller the tank you need.

 

[vanapplebomb]

You can't have too much SCFM, and the more SCFM, the smaller the tank you need.

I’m not sure I would say that. Smaller tanks have less reserve capacity, so the compressor will cycle more often, which is hard on motors. High flow pumps naturally go with big tanks so that they can fill up quick, then power down and run off the reserve air in the tank, which reduces the duty cycle the pump and motor experiance.

 

[Bretny]

An overkill air compressor just means it has to work less, thus should last longer. 6scfm is a bit small for hvlp painting no?

I have a 60gal husky that does everything i can ask for. Same dutys as your asking of yours plus some light DA sanding and sand blasting. Lowes has deals durring the holidays, buy a 60gal compressor get a $100 gift card. Mine is 10yrs old.

 

[TRWham]

I’m not sure I would say that. Smaller tanks have less reserve capacity, so the compressor will cycle more often, which is hard on motors. High flow pumps naturally go with big tanks so that they can fill up quick, then power down and run off the reserve air in the tank, which reduces the duty cycle the pump and motor experiance.

Yes, the number of cycles is lower and that may be good, but the run time and duty cycle (% of time on over time) are exactly the same. A given compressor with a larger tank will simply run for longer duration less often to produce the same usable output. The total run time and corresponding off time don't change, so the heat built up in the motor and head may still be an issue. For any continuous process, you really need a compressor that can move at least as much air as you consume over time at a duty cycle it can withstand. At 100%, it could be half the size of a compressor that can only run 50% of the time.

 

[Citation]

I think in general when you are stepping up to a 240V compressor you are going to either go with a 60 gallon, 10-14 CFM (3-3.7 hp) or an 80 gallon 4+ hp, 13+ CFM. There really isn't much overlap and it seems few offer a more powerful pump with a smaller 60 gallon tank or the reverse.

The tank size, pump power trade off seems to be a bigger issue for the 120V models.

 

[vanapplebomb]

For any continuous process, you really need a compressor that can move at least as much air as you consume over time at a duty cycle it can withstand. At 100%, it could be half the size of a compressor that can only run 50% of the time.

If the only thing you are ever doing is running a constant high flow tool over long periods of time at rated cfm of the compressor, then yeah, that is true. But, be honest, how often does that ever happen? Unless you are non stop painting in a production setting with work flowing past on an automated overhead rack, that just isn’t reality.

Most air tools are used in bursts, which is why big tanks are good for serious air tools. Even with things like a DA sander, or painting a project with an HVLP, you are not going to go for 10+ minutes non stop. In normal shop start stop use, a small tank with a big pump is just going to kick on and off more frequently and rapidly. Think of how quick a 7.5hp two stage pump will fill a 60 gallon tank from 145 up to 175 psi. That sort of pump really belongs on an 80 gallon tank minimum. Anything less will really tax your motor, particularly single phase motors which start by a centrifugal switch temporarily engaging the starter winding.

 

[u3b3rg33k]

I've never had an air compressor where I thought the tank was operationally too big. too big to move around, yes, too big to get the job done? not a chance.

An overkill air compressor just means it has to work less, thus should last longer. 6scfm is a bit small for hvlp painting no?

I have a 60gal husky that does everything i can ask for. Same dutys as your asking of yours plus some light DA sanding and sand blasting. Lowes has deals durring the holidays, buy a 60gal compressor get a $100 gift card. Mine is 10yrs old.

on bigger compressors (>5hp) some will actually state that they need to run long/hot enough to prevent internal moisture issues.