Air compressors - which one?

Besides the $30 ones that plug into a cigarette lighter you get from Sears, I've never owned an air compressor, so I really don't know much about them.

Can I get pointers on what to look for? I've just started teaching myself how to work on cars, with my two '76 Fiat Spider project cars. I don't own an impact wrench, but clearly need one. I'd also use the compressor to blow up balls (wait...let me clarify...my kids basketballs, etc.... ) I want to do it as inexpensively as possible. So I'd be looking for something off CL, or possibly from HF if they're any good. The cheaper the better.

The general rule of thumb is "the biggest one you can afford"

Once you own one you seem to find more uses for it. I started with a small 20 gallon roll around unit and it's still in operation mostly being abused at the track when we do Lemons. It will run an impact wrench but it needs recovery time.

In the shop now I have a 60 gallon monster from Sears, I must say I love it and it is much quieter than the little oilless one.

look for bigger numbers- buy the highest cfm rating you can afford. avoid oil free compressors- they are noisy and generally not as powerful as a regular compressor. get a 2 stage if you find one in your price range. get the biggest tank you can fit in your garage..

once you have the compressor, spend a little money for some decent 3/8" hose. cheap hose is a pain to keep under control when you are trying to hang it back up or avoid tripping over it (especially in cold weather), and a bigger hose is like adding more capacity to the tank.

when i was at Harbor Freight a few weeks ago, i saw a 25 foot 3/8" Goodyear hose for just under $30.

my youngest brother bought a demo model 30 gallon 2 stage horizontal Craftsman professional" compressor from Sears a few months ago. i borrowed it from him about a month ago, and was able to operate my die grinder pretty much constantly for about 1/2 hour without the pressure in the tank falling. i was impressed. i think he paid $250 for it, but it's normally a $400 unit. but the craptastic 1/4" air hose they included with it just absolutely sucked in my 25 degree garage..

As has been said, get the biggest you can afford. I would get one with a cast iron compressor instead of an aluminum one. No oiless/direct drive units unless I needed a small one for a specific purpose, like purging the irrigation lines in the yard.

I recently bought a cheap, 2.5hp oil-based direct-drive compressor, and even that is brutally loud. Can't imagine what an oiless one must sound like.

It's fine for inflating tyres, which is about all I use it for, although the box says it will run air tools for a short period of time. I also bought the matching store-brand el cheapo hose-kit, which definitely sucks .

If you have room for it, bigger is better. I bought a 20-gal and hated it, ended up returning it. I then kept an eye out for deals and happened to spot an 80-gallon 2-stage 175psi monster at Lowes on absolute clearance ($400 for a $1000+ compressor!) and snapped it up. That was close to 10 years ago and my only regret has been when I needed to move it. It is amazing. Yes, it takes up 9 square feet of my garage, but it will spin off the most frozen bolt (or break it in half) or run a paint gun non-stop or grind continuously or sand forever or .... etc.

Buy this impact wrench:

http://www.harborfreight.com/1-2-half-inch-impact-wrench-2623.html

I promise you will not regret it. You don't even need to hold the crank still to spin off a crank bolt. Assuming your compressor is up to it.

Honestly you probably don't need the 80-gallon 2-stage 175psi monster, but Thw8's guidance is spot on: get the biggest you can afford.

I agree. If you have the space, get a 2-stage oil version with a large vertical tank. I have a 25 gal oilless from Sears that I bought some 15+ years ago. It will run an impact wrench and fill tires, but that's about it. It does not like to run my cut-off wheel at all and doesn't even like an air-ratchet all that much.

And it's loud as hell.

The one good thing about it is it's portable enough that I can strap it down in the back of my Jetta wagon w/o folding the rear seats down.

i've got this one from sears. the 25 gallon tank is a little on the smaller size of this category but its got a big ballsy oiled air pump so its pretty quiet, still portable, and the pump can keep up with most of my cutoff wheel jobs. skinning the jeep's hood needed some recovery time but that was a LOT of cutting. i looked for bigger CFM numbers more than peak pressure or volume. i think i picked it up for like $370 on sale too.

http://www.sears.com/shc/s/p_10153_12605_00916475000P?blockNo=11&blockType=G11&prdNo=11&i_cntr=1300458441551

A 60 gallon tank makes a compressor about 10x as good as a 30 gallon tank. A 30 gallon tank is about 10x better than a 10 gallon.

Save your money and buy a big one. You won't regret it. I was given a 30 gallon Craftsman, and it works great for nearly everything I do. Impact wrenches, filling tires and many other air tools. It's almost too wimpy for my die grinder, and way too small for my angle grinder. I can use it for painting touch-up and panels only--I couldn't paint an entire car with it.

Save your money for a little while longer during your search. You'll be rewarded with a tool that lasts you the rest of your life.

I have a 5hp 150 psi oilless. It's ungodly loud. The 30 gal tank can't keep up with a DA, grinder or cutoff wheel. Barely with a paint gun. It will run a couple of air nailers though. I've struggled with it and gotten by, but it's not the compressor for much car stuff - maybe trackside. Go for 2-stage.

I have a 30 yr old 220v 20 or 25 gal 2stage horizontal compressor from Sears. It operates huge airhog 1/2" impacts all day long with minimal running. When it does run, it is literally 30 sec at a time.

If I really had the cash and garage for it, I'd have a huge rotary screw compressor with dryer attached.

Single stage oilless pumps tend to be cheaper, aluminum, and very loud. They also tend to have proprietary (non replaceable) parts. When they wear out, they wear out.

cast iron oil bath pumps (typically belt driven) are much quieter and if they wear out,(which they rarely do) individual parts can be replaced or repaired. The 300 gallon Ingersoll Rand compressor at our transmission shop has been there untouched for 18 years, and it gets used HARD. If the motor dies, its as easy as replacing it with another 360v 8hp motor. If the compressor dies, I just call up one of several companies and get a rebuild kit.

You'll find that most cast iron oil-type pumps are two cylinder, but unlike many of the ones listed above (sorry guys) they are not two stage. A two cylinder pump can be single stage - meaning that both cylinders compress air directly into the tank. Back in the day, you used to have to buy a two stage pump to get higher pressures. In that case, the first cylinder would pump air into the second cylinder for higher pressure, then the second cylinder sent it to the tank. With the amount of pressure that can be generated these days with just one stage makes a two-stage pump almost obsolete.

I have this a Craftsman horizontal 5hp 60 gallon. It has a belt-driven two cylinder single stage pump. Its actually made by Ingersol Rand for Sears. I think I paid $400 for it a few years ago. I think that size and type is perfect for even the hardcore home hobbyist. I have done everything including paint entire houses with it. Really high-draw items like grinders and cut-off wheels will get ahead of it, but its not a big deal. Truth be told, those little rotary air tools can get ahead of a 300 gallon industrial compressor sometimes.

I have an 80 Gallon two stage (real two stage) Ingersoll Rand and all I can say is Amen. Hopefully this will be the last compressor I'll ever have to buy. I used to get so frustrated when I would have to stop and wait for my 30 gallon oiless to catch up whenever using a DA and you could forget sandblasting, grinders, or painting anything large. There are certain tools that are worth spending the extra money on.....a good compressor is one of them. Nothing has gotten ahead of this compressor so far and that's a great feeling. I'm just a home hobbyist, but I'm so far along that most people would not consider it a hobby....maybe addiction.

Cotton wrote: I have an 80 Gallon two stage (real two stage) Ingersoll Rand and all I can say is Amen.

Amen indeed. My dad has one of those that is either 100 or 125 gallon and its about as good as it gets.

i just got a 6 gallon one for christmas and its pretty awesome.

I was just debating this question.

Is it pretty much a requirement to go 220v or can you make do with a 110v? At some point in time I'm going to (badly) paint a car I have with it.

Brett

I would say a 30 gallon unit is about the minimum a car guy can use decently. I have a Porter Cable 29 Gallon I bought a lowes 10 years ago. It's fine.

but as mentioned:

Being a single stage: it LOUD. as it's in the garage and I can hear it running in the basement.

Runs impacts, rachets, hammers fine. but not a grinder.

I'm looking at going to a 60+ Gallon 2-stage Belt driven unit when I find one affordable.

curtis73 wrote: Single stage oilless pumps tend to be cheaper, aluminum, and very loud. They also tend to have proprietary (non replaceable) parts. When they wear out, they wear out.

I was never a fan of the oilless compressor, but a buddy lost his storage, and kept his 20 gallon Craftsman oilless in my shop, where it was abused for about 4 years. I eventually put a cylinder, and ring set in it. The parts were about $30 from Sears, delivered to my door.

They're not pro level compressors, but even for fairly aggressive hobby use, I don't see a problem with them. They are noisy.

Cotton wrote: I have an 80 Gallon two stage (real two stage) Ingersoll Rand and all I can say is Amen. Hopefully this will be the last compressor I'll ever have to buy.

That's where I'm at. I don't know if it's a "real" two-stage, but it's a Devilbiss that claims it's 2-stage, and it provides enough air for absolutely anything I need to do. I love having a tool that will last me a lifetime. It's very reassuring.

Brett_Murphy wrote: I was just debating this question. Is it pretty much a requirement to go 220v or can you make do with a 110v? At some point in time I'm going to (badly) paint a car I have with it. Brett

I would say the one WIlber posted to be a good minimum. It can run either voltage. There was a big lawsuit about compressor HP a few years ago and now the ratings are more in line with what they really are. A 5 hp back then is a lot less now. I real 5 hp motor draws far more amps than a standard 110-120V household circuit can handle (56 amps @ 115V).

Another thought is if you plan to paint with it, make an effort early to keep the tank clean. Even consider installing a drier set-up between the compressor and the tank. When I get a large vertical tank compressor, a must-have will be an automatic drain valve. I wouldn't dream of trying to paint a car with the crap air from my 15+ year old tank that I don't drain anywhere near often enough.

To the OP: Depending on what you need it for, do you really want a compressor?

There are certainly things only compressed air can do (paint, inflation... chisel?), but I don't fire up my compressor much since I got my Craftsman LiPo-battery impact wrench. It's not as powerful as a big air-powered unit, but it does a lot.

Given the noise, expense, and space taken up, I'd give it a think. Air compressors are great to have around, and I plan to upgrade mine at some point, but you can do a lot with electric tools at this point at greater convenience and using up less space.

If you continue working on cars, I'd hazard that you will eventually want a compressor. But I also think you'll eventually want both kinds

How big a compressor do you need to paint? I want to paint my bike fenders and tank. I only have a small compressor available.

93EXCivic wrote: How big a compressor do you need to paint? I want to paint my bike fenders and tank. I only have a small compressor available.

for small stuff like that a 30 gallon is fine, but you need good filtration becasue those small compressors get hot and generate a lot more moisture. For something larger you need a big compressor. Painting and sanding my cars/projects are the main reason I bought my 80 gallon two stage.

I have a 30gallon 1HP homemade compressor out of like an old boiler or something. It must weigh about 250lbs. It is wired for 120V 15amps but keeps kicking the breaker when the pressure reaches 90psi. It uses a single piston harbor freight motor and a 1hp electric motor. The selling point is it was very quite, but it needs to be rewired for 230v. I'm thinking about selling it and getting a decent compressor, my Uncle couldn't stress having a good compressor.

My other compressor is a little porter cable which is so loud it make you hate life while it is on. I have a Junn-Air but it needs repair. As soon as I get the junn-air working I'm getting rid of the porter cable noisemaker.

I'm starting to look for a decent compressor myself. I'm going to put it in the basement and run air lines into the garage. I'm also going to put a solenoid on the drain so you just flip a switch and it drains. I spend a week in the basement with a jack hammer so I could fit a large compressor down there.

Ian F wrote:

Brett_Murphy wrote: I was just debating this question. Is it pretty much a requirement to go 220v or can you make do with a 110v? At some point in time I'm going to (badly) paint a car I have with it. Brett

I would say the one WIlber posted to be a good minimum. It can run either voltage. There was a big lawsuit about compressor HP a few years ago and now the ratings are more in line with what they really are. A 5 hp back then is a lot less now. I real 5 hp motor draws far more amps than a standard 110-120V household circuit can handle (56 amps @ 115V). Another thought is if you plan to paint with it, make an effort early to keep the tank clean. Even consider installing a drier set-up between the compressor and the tank. When I get a large vertical tank compressor, a must-have will be an automatic drain valve. I wouldn't dream of trying to paint a car with the crap air from my 15+ year old tank that I don't drain anywhere near often enough.

yea mine's wired from sears at 110v but it's RIGHT at the limit of older 15amp circuits and usually beyond when it kicks on at higher pressures. i actually have a 35 foot extension cord running to a newer 20a circuit and it's never been a problem there.