Air Compressor advice

[Reverend]

Looking to get a 60 gallon air compressor and been doing some lite reading on the subject. I am seeing single and dual stage compressors out there. I know what the difference is along with the price difference. Is a dual stage worth the price, for a small time guy like myself? Your thoughts..... go

 

[shamrock12]

Dual stage allows you to build up higher pressure inside the tank which means more air for your disposal between cycles.

Do you have some tools/equipment that would consume alot of air in a short period of time under continuous use, such as sandblaster, etc? If not, then single stage probably will be just fine.

 

[md21722]

Get a dual stage if you can afford it. Many single stage air compressors have cut in at 90 and cut out at 125, or maybe 100-135. Some have adjustable pressure regulators, some have poor adjustments, and some do not have any adjustment at all. Plus single stage air compressors typically start struggling past 110 PSI anyway. They slow down if you will. In other words it might take X time to go from 80-100, but it will take X*2 time to go from 110-130. Dual stage gives you 40% more air storage, and they more or less pump linearly as the pressure goes up. Why is this important? Because air tools are designed to run at 90 psi. By the time you have your air hose, regulator, drier, and what not in there, you probably shed 15 psi (if using just a 25 foot hose!) So your impact wrench would see 70-75 psi delivered (even if your regulator is set at 90) before your air compressor ever kicked on. With a dual stage the cut in and cut out is typically 145-175. Your air tools won't see low air pressure unless you are exceeding the capability of the compressor. As a side note, the regulator is set so that the tool sees the right air pressure. To test, generally you put a gauge at the tool. It's common practice to take a T-fitting and put an air plug, coupler, and gauge on it, and then you connect it to the end of the hose and tool. Then you set your regulator so that when operating the tool, the gauge at the tool still says 90 (or whatever you want to run it at). You will end up setting your regulator so its gauge says 105 or more, most likely.

 

[bdelmar2]

Depends on what you plan on doing really.

For general mechanical work you don't need the dual stage. I work in a trans/mechanical shop with 5 people in it, 4 working steady and we have an old husky single stage poorly plumbed.

Very seldom have an issue with available air pressure, maybe once a week or so depending on whether or not somebody is running a cut off wheel or blow drying parts for extended periods.

Now it does run quite a bit, and I really don't know why it hasn't blown up yet, but it hasn't. Had to replace a belt about a year ago, and the pressure regulator about 6 mts ago. Owner said belt was original and the regulator was for sure.


In the 18 months or so I've been there I've run into maybe 3 or 4 things I couldn't pull with the setup and a good 1/2" impact. The subframe bolts on a Honda oddessy are one I remember, ended up with a 3' cheater pipe on a 24" breaker bar and it was still all I could do to break them loose, and I'm 6'2 and about 320lbs.

I didn't have my 3/4" impact at work, that and a good compressor with big line probably would have pulled them, but I don't think any 1/2" would have. The other couple times I think a good compressor/line would have let me pull them with air.


At home I have a dual stage compressor with a better line setup. Tools are noticeably stronger, but given how many vehicles we run through a week at work without much air related hassle I can say you don't really need dual stage.


Now if you are going to be doing any bodywork/sanding/painting or running other high speed air tools its a different story, or any sandblasting. Then you are going to want a dual stage or plan on waiting, a lot.

Even with a dual stage you are going to want to give it a break now and then if you are running it hard so you don't burn it up. Unless you spend a lot of money on the compressor - more expensive compressors have higher duty cycle ratings.


Still even though you may not need a dual stage, I'd still get one if you can afford it.

I think its better to have the extra capability and never need it rather than need it and not have it. Plus if you ever decide to sell it, you will probably have better luck selling a dual stage than a single.

 

[roblouvasz]

Don't buy any Ingersol Rands from Tractor Supply! You'll regret it! (ask me how I know) I would also stay away from anything from Lowes or Home Depot.If you can find a used air compressor such as Quincy,Saylor-Beall, Champion, DV Systems or Jenny, I would seriously consider those. In the past ten years my I/R has given me issues in the middle of three different projects. I didn't know much about air compressors ten years ago but I know I needed a two stage for what I had planned on doing that's why I picked the IR. I thought it was a good compressor because of the name. Boy was I wrong. Had I have known, I would have gotten one of the above listed brands. Well just last week, The second motor went on my IR. I made the decision to get another Compressor. I was going to spend 3000.00 for a DV Systems but found a used Quincy for 1550.00. Trust me, there's nothing more aggravating that having no air in your shop. I do have two different threads going right now about my search you should check them out.

 

[Jim Johnstone]

You're overlooking one of the biggest reasons to go 2 stage. Most single stage compressors are commercial quality, spins high rpm, and not very heavily built. The 2 stage pumps are typically geared more towards industrial use, much heavier construction and low rpm. Which means on average, the 2 stage pumps are probably going to outlast a single stage pump by a long margin.

I had a 3 cylinder, 5hp single stage. It wasn't very heavy, it did put out a lot of air however. The downside was it ran at something like 1450 Rpm, was ungodly loud, and the pump got stupid hot when I was using it a lot such as using a DA sander or blast cabinet.

 

[md21722]

You're overlooking one of the biggest reasons to go 2 stage. Most single stage compressors are commercial quality, spins high rpm, and not very heavily built. The 2 stage pumps are typically geared more towards industrial use, much heavier construction and low rpm. Which means on average, the 2 stage pumps are probably going to outlast a single stage pump by a long margin.

I had a 3 cylinder, 5hp single stage. It wasn't very heavy, it did put out a lot of air however. The downside was it ran at something like 1450 Rpm, was ungodly loud, and the pump got stupid hot when I was using it a lot such as using a DA sander or blast cabinet.

Not all dual stage are industrial quality. Check out your local Lowe's or farm and ranch store for the specials. To get top quality today you have to pay $2,000 or more if you're buying new.

 

[Jim Johnstone]

My local lowes, tsc, home depot etc don't sell anything 2 stage at all. And I realize not all 2 stage pumps are industrial quality, but the vast majority of them are substantially better built than a single stage pump. Case in point are the Saylor beall knock offs you can get from the likes of princess auto in Canada. Virtually a clone of a SB 705. Only a few hundred bucks more than a single stage pump with similar cfm. Yes they are Chinese, but they are also twice the weight and spin half the rpm of the Chinese single stage pump on the shelf beside them. Given a choice between the two, I'd take the Chinese low rpm 2 stage everytime.

Virtually every single stage pump I've seen uses tiny pistons and spins way fast. Bad combo for long life.

 

[redmondjp]

Not all dual stage are industrial quality. Check out your local Lowe's or farm and ranch store for the specials. To get top quality today you have to pay $2,000 or more if you're buying new.

That's for sure! There are plenty of consumer-grade 2-stage compressors out there with splash-lubed pumps running at high speeds. They are very loud as well.

 

[Reverend]

Thanks gents, good food for thought. Noise will be a big concern, it will be outside in a shed and the old lady next door ******* about everything. I guess i will add somthing to her list.

 

[Tinker Man]

No matter which compressor you get don't forget to change the oil and air intake filters. I have an old 1955 Quincy 325 record of change 7 and I am just rebuilding it. This compressor with a few upgraded parts is capable of 500 psi. I run it at 175 psi. This unit was originally used on an ocean going tug boat for starting the air start diesel engines.

I have been told by many, including one straight arrow Quincy rep, you can't go wrong rebuilding one of these even though some of the parts are expensive. I acquired this for next to nothing and my parts cost have been reasonable at 400 and change. Once rebuilt these Quinces will last another 60 years if you keep the oil changed.

Not everyone wants to rebuild an old one... I'm telling you this so you'll know get a quality unit and you won't be disappointed when you need it for a project.

Now I'm off to start rebuild the old Quincy 240 ROC 8 I acquired at the same time. IT has two 4 inch pistons and I am looking for one piston.

Sun is rising, daylight is wasting and I'm choppin' at the bit to go.

Great day to everyone. Ken the Ancient Buzzard.