Air Compressor

[The Dude Abides]

I was wondering if anyone could recoment a good brand, size air compressor to get. Not over 500 bucks. Something to run air tools obviously. But something to do some minor painting as well. Im not trying to break the budget on this one. I dont mind it coming on alot but i dont want it running constantly.

 

Ben

[TheSubaruJunkie]

General Disorder is your man on this. He works with these things all day.

[NorthWet]

A little something to think about before GD and/or others provide some good info:

Air tools like oil in the air; paint does not. Make sure your filter/lube setup reflects this, and make sure that you use dedicated hoses (not contaminated with oil) for your painting. Seems obvious, but it wasn't to me when I started.

[GeneralDisorder]

Well - the first question I have to ask is what you want to do with it? I mean specifics. All air tools have different requirements. An impact will use very little air in comparison to a drill, die grinder or air-board.

 

You can use the same compressor for both your air tools and for painting. Painting is going to require some additional accesories that air tools will not. For a paint system you will *want* some form of vapor seperator, and you will *NEED* a filter and a regulator. Many air tools will also require a regulator.

 

Now vapor seperation can be as simple, or as horrifically complex as you can imagine . I can be nothing more than an automatic drain on a large receiver tank, or it can be a refrigerated or dessicant air drier.

 

What is a-lot for you? You say you don't want it comming on a lot.... that is largely dependant on how big of a receiver you use. How long it stays on once it starts is dependant on the size of the air-end and how fast you run it.

 

How much space do you have to work with? Do you want something that is portable, semi-portable, or "oh my god I hope I never have to move that sucker again!"?

 

I'll give you some ideas of what *I* like. Bear in mind I do get this stuff for nearly free so it's just to give you an idea of what is *nice* to have, not neccesarily what the minimum you want for yourself would be. Also I am partial to the brands I work with most... I also happen to beleive them to be of superior quality in most respects... and they are made right here in the US. That said....

 

I personally (and ALL my co-workers) swear by the Quincy QR series recip (piston) compressors. They are full-industrial machines that can be handed down to your children. I have worked on fully functioning QR's from the 1940's. They can be rebuilt and maintained indefinately unless they are seriously abused (which actually happens a lot because they are generally so reliable that people forget about maintenance).

 

For my garage machine I have a vertical 80 gallon tank with a QR-325 run with a single-phase, 5 HP motor. It lopes along at 850 RPM and puts out a solid 22 CFM at 150 psi.... and would do it 24/7 if I wanted it to. It's a bruiser of a machine though. Just the air-end weighs about 250 lbs. Cast iron and all that. The drive motor and the tank make it a 600 lb machine... or more. To move it I have to have a friend help me dissasemble it .

 

Anyway - I'm not sugesting you buy one of these, but it's a high-water mark to shoot for. MANY air tools require 10 CFM, and a small sand blast cabinet would easily consume all the air I can make with my 325.

 

The vertical tank is nice from a space premium standpoint and the height would keep children's fingers away from harmful moving parts and hot metal.

 

If I were buying a machine outright I think the Quincy QT series are priced right for the competitive consumer market. I would look at a vertical tank mounted QT-5 or QT-7.5 with either a 60 gallon or an 80 gallon tank. The QT's differ from the QR's in their valve system and their lubrication systems. Where the QR's use an oil pump and automotive style filter the QT's use a simple splash lubrication, and where the QR's use an industrial cast-iron disc valve the QT's use a reed valve system. The reed valves in the QT's don't last as long and when they go it's generally cheaper to just buy a new air-end. But the packages are nice and the quality is fine for a home shop.

 

Don't cheap out on your filtration - getting replacement elements is difficult if you but cheap units. Wilkerson is my preference.

 

Anyway - give me more info and I'll narrow your options.

 

GD

[GeneralDisorder]

Also.... in regards to your concern about it running too often.....

 

Bigger air ends can run slower, and this has the benefit that they are *quieter* when in operation so you don't mind them as much. Most people associate compressors with being VERY loud peices of equipment. That is only true of the cheap machines that have to run extremely fast to make decent air. Running them fast wears them out quickly and makes them loud, hot, and annoying. Generally the higher quality the machine, and the larger it is, the quieter and cooler it will run.

 

GD

[GeneralDisorder]

Just saw the $500 part

 

..........

 

Basically you're screwed.

 

Even a QT-3, which puts out around 6.5 CFM, will be hard pressed to run a die grinder for more than a few minutes. And most of them come with pretty small tanks.

 

Something like this:

 

http://www.tools-plus.com/quincy-131a30vc3a.html

 

And even that is outside your budget range.

 

I would check out some auctions in your area. If you can find a used QR package (there's lots of them out there) you can buy a 5 HP single phase motor (anything you find will likely be 3 phase) for around $250 and be in business.... with maybe some minor repairs.

 

GD

[The Dude Abides]

Gd that was a font of knowledge. Thank you for typeing it up for my cheep butt lol. No something big for latter but right now something to run an impact wrench, air hose (duh), and some painting. Now i dont mind waiting around for the air to catch up but im looking around 35 gallon. Ohhh i just saw this one GD. What do ya think.

 

http://desmoines.craigslist.org/tls/774370808.html

[The Dude Abides]

i know this isnt as impressive but what would something like this do for what i want. Now dont me

 

Ben

 

http://desmoines.craigslist.org/tls/736932167.html

[GeneralDisorder]

That first Quincy you posted for $500 is a good deal. That's a QT-5 and with a single phase motor at that. That's about a $1500 package to buy new. I've seen worse deals. Buy it, love it, and when you have a few bucks handy PM me and have me purchase you a valve rebuild kit so you can prolong the life of the machine. It's always the valves that go on those. The kits are cheap and easy to do but people wait till the reed valves snap off and destroy the cylinders and heads.

 

I get all parts at cost through my work as we are a Quincy distributor/manufacturer.

 

The second one you posted is pure Chinese garbage. That's the high-RPM, loud, poor quality, annoying crap I was referring to. Notice that it's labeled as a 6 HP unit.... yeah right. If you actually read the motor data plate it will list the full load AMPS as "special" or "SPL"... it means the HP rating (which is a mathematical calculation) is taken under very specific conditions. This is often labeled as "peak" HP. It's a total marketing gimick used to sell what amounts to a 2 HP motor as a 6 HP instead. Notice the size of the 5 HP motor on the Quincy is nearly as big as the whole motor/compressor/plastic POS on top of that Craftsman tank? That's because the 5 HP on that Quincy really IS a 5 HP motor.

 

Get the Quincy - you won't be dissapointed, and with that 80 gallon vertical and 5 HP motor you can upgrade to a QR when you find one cheap. Plus I could get you any parts you need at wholesale and I can ship them through my work for peanuts.

 

GD

[The Dude Abides]

Thanks for all your help gd when its not 2 in the morning lol ill call them.

 

Ben

[Numbchux]

well, contrary to GDs belief....Craftsman compressors are pretty nice. me and a couple buddies all have them, and they work great. quieter and more reliable than most consumer-grade compressors.

 

here's the one I bought for $150 listed on craigslist about a year ago:

 

nice and quiet. 7.7 CFM @ 90psi...so a little on the small side, but I run my impact wrench, die grinder, and air hammer on it all day. never had to wait for it to pressurize (as long as it doesn't blow the circuit breaker....but that's not the compressors fault). I have it inside the entryway of my house (no garage), and run a long hose out to the driveway, can't even hear it run out there, it's awesome. also easily fits in my wagon and can be lifted by one person, so very portable. probably a little on the weak side for painting....

 

The guy I bought it from had had it for ~15 years. used it for his wood shop, and the only reason he sold it, is because he bought almost the exact same one, just a little bigger.

 

 

my dad has a cheap generic one that's loud and weak, you have to give it 30 seconds between lug nuts.....I think he probably paid $150 for it when it was new 15 years ago.

[GeneralDisorder]

well, contrary to GDs belief....Craftsman compressors are pretty nice.

 

Don't get me wrong - those are fine if you are just running a nail gun or an impact every other saturday. But they wouldn't stand up to even light commercial duty for long. It's the nature of the machine - tiny tank means it runs a lot if you are using needy air tools, no coolers so they get crazy hot on the discharge side, and that's a form-x setup so the first thing that will go is the check valve from the discharge to the receiver - then it won't start again once it's tank is pressurized.

 

7.7 CFM is *just* enough to run most die grinders and drills.

 

I just see this stuff every day - most people know better than to bring us stuff that cheap (although it does happen).... would cost them more to have us tell them whats wrong and that it's not worth fixing than it would cost for them to buy another one.

 

You can't have enough air on your budget. Buy the QT and you'll have a much easier time doing what you want.

 

GD

[Numbchux]

I use this one with my impact and/or air hammer 3-4 days a week. year round (that entryway is not insulated). still works like new. I don't use the die grinder often...so it's not working to capacity. which is exactly what I'm saying, this is plenty to last your average home mechanic a few decades. no, it's not industrial-grade.....but pretty much top of the line consumer-grade.

 

 

I've got to get a better oiler though....that cheapo POS I put on there just doesn't work.

[GeneralDisorder]

I use this one with my impact and/or air hammer 3-4 days a week. year round (that entryway is not insulated).

 

Cooler is better for compressors. Many are located outside and they should be. The ones we have problems with the most are indoors in poorly ventilated rooms.

 

 

still works like new.

 

Does it? That's a twin cylinder single stage - other than pumping slower you likely wouldn't notice a discharge reed valve failure in a single cylinder. Those valves are rated at about 1000 hours before they need to be replaced. After that it's borrowed time till they snap off and cause all kinds of irreparable cylinder and head damage. I can't even count the number of broken reed valves I've seen.

 

I don't use the die grinder often...so it's not working to capacity. which is exactly what I'm saying, this is plenty to last your average home mechanic a few decades. no, it's not industrial-grade.....but pretty much top of the line consumer-grade.

 

There's plenty of products that are better and just about the same price as that craftsman. Craftsman has the advantage that they are widely available and the only place a lot of people know of to buy stuff like that. But an IR, Champion, or Quincy are all going to be better quality and about the same price. A 2 HP Quincy QT3S on a 12 gallon tank would perform just as well as that Craftsman you have and cost about the same new.

 

I've got to get a better oiler though....that cheapo POS I put on there just doesn't work.

 

One thing that helps is to install a filter and a vapor seperator with an auto-drain. The more water and contaminates you get out of the air BEFORE it gets to the tools, the less oil you need, and the longer your tools will last. Frankly with clean, dry air you don't even need an oiler. Just 5 drops of oil in your tool's air inlet once a week is sufficient. Plus it doesn't contaminate your hoses so you don't need to keep both oil free and oil flooded hoses around

 

GD

[Numbchux]

Cooler is better for compressors. Many are located outside and they should be. The ones we have problems with the most are indoors in poorly ventilated rooms.

 

I suppose.....but it blows the circuit breaker muuuuuch more frequently when it's cold. definitely working harder.

 

 

 

yes, mine does still work like new. say what you want, but this is the best compressor it's size I've ever used. And yes, I've got a buddy with a Quincy.....which works similarly well, but probably makes twice as much noise to do it. only one outside a shop that I like better is also a craftsman......just a much bigger (and not portable) one.

[The Dude Abides]

that quincy ended up getting sold. when it comes down to it ill probally just try to find something used for now. i can get a sears one fairly chep with a 36 gallon tank but ive got some more checking to do.

 

Ben

[montana105]

I'll add a different perspective here.I sold air tools and compressors for years at Sears?Craftsman.For the average home owner doing DIY repairs and mechanics there is nothing wrong with the Sears/ Craftsman stuff.The new stuff offered though is a different story.Heat is the enemy,and Sears as many of the home improvement box stores has gone to the no oil lube system and I've found that these systems produce more heat which produces more moisture through the line to your tools,without adequate separation systems this will ruin not only your air tools but will ruin any attempt at a quality paint job.This is okay for the casual user who maintains their air tools,but be diligent with your sprayers.The main thing I've found with using Sears compressors to do any spraying is to not use just an air hose,design a system that runs through piping with oil and water separators/filters.Air tools can handle some moisture but be diligent with your oiling of your equipment.All air compressors produce moisture just from the simple fact they are compacting air,without the right equipment you'll never get results and if you don't bleed your compressor daily you are screwed.

[GeneralDisorder]

I suppose.....but it blows the circuit breaker muuuuuch more frequently when it's cold. definitely working harder.

 

Then you need to go to a lighter weight oil. SAE 20 is what I reccomend for cold environments.

 

 

yes, mine does still work like new. say what you want, but this is the best compressor it's size I've ever used. And yes, I've got a buddy with a Quincy.....which works similarly well, but probably makes twice as much noise to do it. only one outside a shop that I like better is also a craftsman......just a much bigger (and not portable) one.

 

All reed valve machines make a lot of noise. It's the valves, the fact that there is just less metal in the machines, most small ones have no intercooler, and then they have use an external tank-check valve which rattles when the compressor is in operation. Then they blow-down the discharge line using a form-x pressure switch because reed valve machines are unable to start under load (discharge line to the tank must be depressurized). Then they mount them on un-reinforced tank saddles and spin them at horribly fast RPM - people want CHEAP is what it comes down to. They take a small, cheap pump and spin it very fast... it's going to be loud. People want cheap - that's why wall-mart makes so much money. Even Quincy has to compete against IR and even Craftsman. There is a market for it and unfortunately that drives UP the price of the decent machines because fewer people are buying them. Beleive me.... I know this all too well and I deal with it every day. It's sad - I'm rebuilding a 43 year old QR machine at the shop this week and besides needing a good overhaul it still performs TO SPEC! It's weeping oil from everywhere - but it still makes just as much air as it did when it was built in 1965. Try that with your Craftsman.

 

Spin a smallish QR at a nice 750 RPM and you will know the definition of quiet. They are so quiet in operation that you can hear the disc valves clicking. Plus they have a nice low-pitched rumbble - sort of like the difference between an idleing mopar and a weed whacker.

 

GD

[GeneralDisorder]

The new stuff offered though is a different story.Heat is the enemy,and Sears as many of the home improvement box stores has gone to the no oil lube system and I've found that these systems produce more heat

 

Oil-free recip's are TEH SUCK.

 

When they fail, they fail in a big, nasty, loud way. Usually accomanied by a lot of smoke.

 

You may not have oil in your lines, but one day soon you will have compressor metal and teflon in them .

 

If you want decent oil-free, look at a scroll compressor. Powerex makes a neat little unit.

 

http://www.powerexinc.com/index.asp?fuseaction=productDetails&product_subcategory_id=23

 

GD

[Numbchux]

FYI, I just happened across the manual for this compressor. date on it is 6/89.

[GeneralDisorder]

FYI, I just happened across the manual for this compressor. date on it is 6/89.

 

Sure - but how many actual run hours are on it? Age doesn't matter as long as they are stored in a clean dry environment.

 

I doubt it has 1000 hours on it. Most inexpensive reed valve machines are rated at 1000 on the valves. The Quincy reed valves are rated at 3000 hours which is typically about 3x what other manufacturers give them.

 

GD

[The Dude Abides]

Sure - but how many actual run hours are on it? Age doesn't matter as long as they are stored in a clean dry environment.

 

I doubt it has 1000 hours on it. Most inexpensive reed valve machines are rated at 1000 on the valves. The Quincy reed valves are rated at 3000 hours which is typically about 3x what other manufacturers give them.

 

GD

 

Now that i think about it at my last job we sold only quincy air compressors for air dryer systems. My boss said thats the only brand he would sell. We got em from some local outfit in desmoines.

 

Ben

[Numbchux]

Sure - but how many actual run hours are on it? Age doesn't matter as long as they are stored in a clean dry environment.

 

I doubt it has 1000 hours on it. Most inexpensive reed valve machines are rated at 1000 on the valves. The Quincy reed valves are rated at 3000 hours which is typically about 3x what other manufacturers give them.

 

GD

 

I don't know. but my point is, it's held up awesome for an average home mechanic for 20 years. I'm sure the Quincy ones are stronger/better/whatever. but most people wouldn't use it enough to justify the extra cost.

 

 

hmmm....3x the durability (overkill for my uses anyway) at almost 5x the cost. I'm no math major, but that don't add up in my book.

 

 

also happened to be flipping through the northern tool catalog that came today. all the grinders/sanders/drills in a price range that I would even look at are in the 4-6 CFM range. sure, there are some high end ones that use 15+ at load.....but those are almost all the $100+ ingersoll-rand stuff. and turn the page and there are some chicago pneumatic ones that put out similar numbers with 1/3 the consumption. turn the page a couple more times and there are ones with slightly less power for 1/5 the price....

 

 

 

the only point I'm trying to make here is that the extra money for such a beast of a compressor would probably be better used elsewhere in this case.

[GeneralDisorder]

I don't know. but my point is, it's held up awesome for an average home mechanic for 20 years. I'm sure the Quincy ones are stronger/better/whatever. but most people wouldn't use it enough to justify the extra cost.

 

A lot of people wouldn't that's true. But most of those people would likely be better served renting one when they need it.

 

hmmm....3x the durability (overkill for my uses anyway) at almost 5x the cost. I'm no math major, but that don't add up in my book.

 

They aren't 5x the price at all. They aren't even 2x the price for comparable machines when you are talking brand new. And when you are talking about used stuff from craigslist, you have no idea what kind of use/abuse the thing has had. At least buying a 20 year old Quincy you CAN get parts and make it virtually like new again for a reasonable price. And in 20 more years when the thing is 40 years old you'll still be able to do it again. You get unlucky on a Craftsman purchase of a 20 year old compressor and you're going to eat it.

 

also happened to be flipping through the northern tool catalog that came today. all the grinders/sanders/drills in a price range that I would even look at are in the 4-6 CFM range. sure, there are some high end ones that use 15+ at load.....but those are almost all the $100+ ingersoll-rand stuff. and turn the page and there are some chicago pneumatic ones that put out similar numbers with 1/3 the consumption. turn the page a couple more times and there are ones with slightly less power for 1/5 the price....

 

The beauty of air tools is how inexpensive they are for the power/performance you get out of them. I personally don't buy the most expensive, nor the most inexpensive air tools. Generally if it's not at least $100, it's chinese crap and it's going to be non-user-friendly, won't last long, and will be impossible to get repair parts for.

 

Also - CFM by itself is a meaningless number. It has to be CFM @ psi. Such as 4 CFM @ 100 psi. A machine that makes 4 CFM @ 90 psi will not keep up with a tool that uses 4 @ 100. CFM goes up as pressure decreases. One mistake that people make all the time is they decide they need more air for whatever reason, and crank the pressure of the machine up. That does NOTHING but make their situation worse as the machine makes less air at higher pressure. Then they come to me and wonder why.

 

the only point I'm trying to make here is that the extra money for such a beast of a compressor would probably be better used elsewhere in this case.

 

I think you are missing my point - it's better, when you are talking about a power source (compressed air is a power source, or "utility" if you wish, just as is electricity) that runs many tools in your shop, to buy the best equipment you can afford. A used Quincy IS within his budget, and would be one less potential frustration for him in the future. It also supports a company that still manufactures something of quality here in the US. Something that is worth more than merely a few hundred dollars.

 

You can have your cheap chinese stuff - I don't want it, it's frustration, or it's implications for the US economy.

 

I know that may sound crazy on a Japanese car forum.... but if the US actually produced a quality car anymore I would be one of the first in line for one.

 

GD

[Numbchux]

Also - CFM by itself is a meaningless number. It has to be CFM @ psi. Such as 4 CFM @ 100 psi. A machine that makes 4 CFM @ 90 psi will not keep up with a tool that uses 4 @ 100. CFM goes up as pressure decreases. One mistake that people make all the time is they decide they need more air for whatever reason, and crank the pressure of the machine up. That does NOTHING but make their situation worse as the machine makes less air at higher pressure. Then they come to me and wonder why.

 

yep. you said my 7.7 @ 90 was barely enough to run drills/grinders. I've got my regulator set at 85psi. and most of the drills/grinders out there only need 4-6 at "full load".

 

 

 

I looked when I was shopping. I was pretty much only looking at Quincys, IRs, and Craftsmans. and for the most part, a similar Quincy compressor to the one I got would have been in the $500 range.