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Are large compressors worth it anymore?

Black Sabbath

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May 21, 2020
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Finally getting into the position to afford a 60-80 gallon compressor to plumb up the shop But am now questioning if it is really the best use of the $$$. Already have a decent cordless setup for impacts and the like but that doesn’t cover things like an air hammer or die grinder but those are more nice to haves then need to haves. Dream of a blast cabinet to go with the compressor but that would be a bit more down the line again. I fear it will mostly end up filling tires and dusting things off which could be done with something significantly smaller and cheaper but don’t want to end up kicking myself for not getting what I really wanted either and being unable to run a cabinet or paint gun when called upon.

And before anyone says it there are no 3-400 dollar commercial units on Craigslist
 
If you've even got the thought that you might want to paint or media blast, just buy the big compressor. I have a small compressor due to space/electrical constraints and it's really only good for airing up tires or a short blast of air hammer.
 
Use the shit out of my selection of die grinders. My existing impacts are stronger and lighter with air. Plasma cutter input. Airing up big tires quickly.
 
I wish my compressor was bigger. 20 gallon tank. Around ~5cfm at 90psi and it won’t keep up with my die grinder.

I fabricobbled mine together. I’m running a true 1.5hp motor that pulls 18amps on 120v. Compressor is only rated for a 2hp motor max at 1800rpm. Due to electrical restrictions I chose to run it on a 30 amp 120v line in case I buy another plasma cutter. I sold the plasma I had because it can’t bend or heat metal.

I vote build one with the biggest pump & motor combination you can run. You don’t need a giant tank if you have a kick ass pump. Nissancrawler had a nice build on the old forum.
 
I have probably a dozen tools that need a 5hp compressor, and another dozen that would do fine on a 110v all but the air body saw and die grinders are now superseded by M18. I have my sweet 5hp 80 gal 2 stage but if I didn't already have it and all those tools I would not go out of my way or spend very much money to get one today. As time goes by the big monsters will be dirt cheap used.
 
On the flip side...

I'm offgrid with a 3500w inverter that runs the whole cabin. It won't start my 40 gallon kolbalt compressor, which means anytime I need the compressor, I just start my 7200w yamaha generator.

With all battery powered tools, about all I use the compressor for is airing up tires...
 
On the flip side...

I'm offgrid with a 3500w inverter that runs the whole cabin. It won't start my 40 gallon kolbalt compressor, which means anytime I need the compressor, I just start my 7200w yamaha generator.

With all battery powered tools, about all I use the compressor for is airing up tires...
When I lived off-grid, I bought a gas powered wheel barrow compressor. Bonus was being able to wheel it wherever I needed it and use it on job sites.
 
a 60-80 gal is a must. splash oil. i can t stand the noisy oiless compressors. if you dont need a compressor like that i'd highly suggest running co2.

much bigger than that, there are all sorts of options


i run a 120gal, shop air. 160psi. all main lines are leak free and can go a week before cycling. leaky connections are an easy fix and are large part of peoples dislike of a shop air supply with lines ran.

if i even think i'm going to need more air, i have another line to feed the 120gall tank from a gas powered compressor. i've only done it a few times for sandblasting... and my solution, is to avoid sandblasting at all cost.


if you have a tow rig that runs 85psi tires that alone is a reason to run a bigger compressor.
 
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On the flip side...

I'm offgrid with a 3500w inverter that runs the whole cabin. It won't start my 40 gallon kolbalt compressor, which means anytime I need the compressor, I just start my 7200w yamaha generator.

With all battery powered tools, about all I use the compressor for is airing up tires...
might as well ditch the 40g kobalt and start using co2. use it as air supply and weld/shieding gas. much faster and more convenient when a big compressor doesn't make sence.
 
I’m I the only person here who gets annoyed by people who size the compressor via the size of the tank? The size of the tank means nothing to me. The hp and cfm are what are important not the tank size. :flipoff2:
Don’t they usually go hand in hand?
Larger tank has a higher HP compressor…
 
Not really I have a 10 hp 120 gallon compressor. My brothers 10hp screw has a super tiny tank.
This… if I could have a 30-40 gallon tank with a 20cfm pump at 90psi sign me up. 99% of the time I wouldn’t need the massive tank filled. Simply just a waste of energy and time because I drain my compressor after each use (lives outside)
 
Im currently building a 1.5 hp with a 60 gal horizontal tank
 
Not really I have a 10 hp 120 gallon compressor. My brothers 10hp screw has a super tiny tank.
A screw compressor where you can easily throttle the output would seem to be a different ball of wax from a fixed displacement piston compressor.
We had a tire guy come at work who had a screw compressor on his service truck, I don't think he had much tank capacity but when the screw compressor throttled up he had all the air he could use.

Aaron Z
 
I’m I the only person here who gets annoyed by people who size the compressor via the size of the tank? The size of the tank means nothing to me. The hp and cfm are what are important not the tank size. :flipoff2:
says the guy running a 10hp comnpressor...

must be nice
rich, bmw driven, yuppie people thinkin:flipoff2: (insert king in the castle borat movie meme)

most of us dream to have a shop that's supply lines carry more volume than the tanks we want:flipoff2::flipoff2::flipoff2:. or the power supply needed to run tankless. i'm still beyond happy to have the 200amps over the 100amps i had in my last shop. me and most dont have the luxury of not thinking about tank size.... i still think about adding more tank volume!


tank gets bigger as the shop does...... until it gets smaller and smaller again (as you get even bigger)


in the (single phase mrkt) 5-25 cfm/ 2-7hp range; tank size matters.( ish ISH). for me 60 gal barely gonna do it busting lugs with a 1" anvil. 120gal gets it done.



screw compressors are the shit, no doubt, my last hourly job was almost 10yrs ago now... i started the air and shut it down or passed on the duty for 500+ people in a shipyard. no tank. i wish i remembered more about them... we ran twin screws side by side, and would alternate mains. (single runs full time and secondary kicks in as needed).


similar to the reason i run invertor weld machines. for the power i have available, i can do 4x, or more, the work a transformer machine can.





like i said in another thread, on my mobile rig i also run a smaller compressor with a low pressure side co2 hooked up, just to keep tank size low without dropping below needed pressure. lots of ways to solve a problem...
 
The volume of big tanks keeps the compressor for constantly cycling, if you run a smaller pump and a big tank that means it will have more air before it needs to come on again. But inversely it will run longer when it does.

You can get a lot more volume/cfm with a big tank and pipe to make the hammers happy, and save the power draw with a smaller motor.
 
Don’t they usually go hand in hand?
Larger tank has a higher HP compressor…
Not once you get into compressors big enough to have a separate head and motor.

I've got two ~10gal compressors. One is an integrated unit with some bogus number of advertised HP on it. The other has a real 4hp motor on it. And then I've got a ~60gal with a 7.5 on it that I need to actually get running.

horizontal tank
Are you a dwarf working in a shop built for dwarfs or do you just like building shit that takes up more floor space than it needs to? :flipoff2:

My shit is all horizontal because it was already but together that way but if I ever have to take a welder to one of the tanks it's gonna become vertical at the same time.
 
I’m I the only person here who gets annoyed by people who size the compressor via the size of the tank? The size of the tank means nothing to me. The hp and cfm are what are important not the tank size. :flipoff2:

No, it bugs the shit out of me too. Large tank can just be a bandaid for poor CFM

Same thing with pressure washers. I don't really give a shit about PSI; I want GPM.
 
Screw compressors are the shit if you're doing media blasting, have a few guys working at once, or have other needs for constant air. For a small shop, it ends up running a lot of time without use.

The cordless tools are great for versatility - no hoses or cords dragging around everywhere. They're great for quick jobs where running extension cords or hoses takes more time than doing the job. They also tend to be heavy sons-of-bitches for impacts and a bit ungainly if you're needing a die grinder or a body saw.

I've got a 5hp/80gal Quincy in my home shop. It runs pretty much anything I need, but it runs nearly continuously when I'm using the media blasting cabinet. Admittedly, there aren't a lot of times that I'm media blasting for hours - or days. So it's more than enough. If I ever found myself doing a bunch more media blasting I'd be looking at options. Unfortunately, screw compressors for single phase are pretty limited. For example, Eastwoods single phase screw compressor is only 12.7 cfm @ 90 psi. My Quincy gives me 17.2 cfm @ 175 PSI.
 
I don't use my compressor as much as I used to given I have cordless impacts that are basically as good as my air ones but it still gets turned on almost every time I'm out doing something because my lift needs it for the locks, die grinders use it, I still prefer the big air impact over the big cordless impact, and various other blowing.
 
IMHO, large compressors are "worth-it" unless its 3-phase and you don't have 3-phase. Then motor replacement or phase converters tend to erase the deal factor. I also know my existing shop feeder won't support more than about 5hp.

I'm dabbling with more tank. My existing compressor head/motor is usually sold with a vertical 40-60gal tank; I only have a 20 because its the portable version. May also setup to marry in a another 5cfm portable.
 
I’ve wondered if I could tell a difference if I went from my 14cfm//125psi/80gal compressor to a 17cfm/175psi/80gal. My current shit works good enough unless I’m trying to sand blast.
 
My compressor went down a couple weeks back and life pretty much sucked without it. I backed my 130cfm multiquip tow behind compressor into the lean to on the back side of the shop and backfed my air system through a quick connect... Still a pain in the ass to go out there and fire it up when you needed it and then go back out and shut it down after you thought you were done with it for a while so you weren't just idling all your fuel away.

My air system has also developed a decent leak somewhere underground, so I will be completely redoing that here soon. Went with 1" pex-al-pex for the main line. Should knock my socks off compared to my current 1/2' pex-al-pex line... Also upgrading my compressor from a 17 CFM Devilbiss Pro Air with an 80 gallon tank to a 24.5 cfm Ingersoll Rand with an 80 gallon tank.

I'd say my number one use of compressed air is a blow nozzle to clean stuff off. I'm constantly using it. I pretty much try to clean everything up outside the shop before I ever bring it in, that way the mess stays outside and I don't have to clean constantly.

I also use die grinders with carbide burrs, and right angle die grinders with flap disks, sanding disks, and surface conditioning disks quite often as well. Occasionally an air hammer or air drill and the occasional sand blasting in the blast cabinet too.
 
most of us dream to have a shop that's supply lines carry more volume than the tanks we want:flipoff2::flipoff2::flipoff2:. or the power supply needed to run tankless. i'm still beyond happy to have the 200amps over the 100amps i had in my last shop. me and most dont have the luxury of not thinking about tank size.... i still think about adding more tank volume!


tank gets bigger as the shop does...... until it gets smaller and smaller again (as you get even bigger)


in the (single phase mrkt) 5-25 cfm/ 2-7hp range; tank size matters.( ish ISH). for me 60 gal barely gonna do it busting lugs with a 1" anvil. 120gal gets it done.



screw compressors are the shit, no doubt, my last hourly job was almost 10yrs ago now... i started the air and shut it down or passed on the duty for 500+ people in a shipyard. no tank. i wish i remembered more about them... we ran twin screws side by side, and would alternate mains. (single runs full time and secondary kicks in as needed).

Funny you mention that. I worked at a shop who's bread and butter was 10-30hp rotary screw compressor service and repair along with a bunch of random industrial equipment. We had a 5 or 7.5hp, i can't remember winch, atlas copco rotary screw I'm sure my boss got for nothing feeding 2 500 gallon recievers. We were mainly field service guys though it was a great combo when a couple guys were doing air intensive stuff like sand blasting and die grinding at the same time.

Rotary screw compressors are the cats ass, I keep 8 crapcos alive from 5 to 250hp these days and wouldn't buy one, the amount of high dollar proprietary stuff on them is ridiculous.

As far as the OP's question you'll find uses for it and you won't regret buying a 5hp machine with a 60-80 gallon tank, you very well might regret a 2hp comp with a 20 gallon tank. It doesn't hurt to find a used 60-80 gallon tank and throw it up in the rafters for more air storage either.
 
I was skeptical about the value of a large compressor for a long time. Had a 1.5hp 120v unit for a while with die grinders and impacts, and the tools worked, but not very well. Never used the air tools because they didn't have any ass. Corded electric was my go to.

Had a painting project come up that pushed me to move up to a home brew compressor, 17.5scfm@90psi, 5hp three phase motor, 60gal tank. Have the pressure switch cut off at 150psi.

Holy fuck do all the tools work better. Everything is faster. I don't see how I could live without it now. Only think I find myself wanting is more tank capacity, but I'll probably piggyback in a second tank at some point in the future.

I want to put in one of those air shower nozzles to blow off with, hanging from the ceiling. I plumbed half of my shop's system with black iron pipe, and the other half with regular pex. Works great.
 
I plumbed half of my shop's system with black iron pipe, and the other half with regular pex. Works great.

I need to plumb my whole shop and have seriously been considering PEX. Any regrets so far?
 
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