Air Compressor Recommendations?

[Dan69GTX]

Greetings Iplayfarmer,

Did you get the answers to your questions regarding scfm, ascfm, etc?

One thing you didn't post is what you might intend on doing with the compressor in the future. If you don't care, that's a mute point. When comparing specs on a compressor you want to compare apples to apples. Most cheaper compressors (what you are looking into) rate the CFM at a lower PSI than the better units. Also they rate the HP at PEAK not "real" hp. I agree what's been said regarding oiless.

Also check design and parts availability - if it's a concern for you. Some have no head gasket, some have disc valves vs reed valves.

If you get a compressor that is rated for 100% - see what they mean by 100%. I'm sure it's not 100% if the humidity is 90% and the temps are 110F.

You just need to figure out what your willing to live with to decide what to get. One idea for air storage is an old propane tank. NOT a WATER tank!!!!. Propane tanks are rated for at least 250PSI. If you keep your eye out you can find them at the dump, landfill, yards and get them free. I'm not talking about the 20 lb tanks - but say 100lb on up - that gives around 30 gallons of air. Also if you will run a compressor a lot - use an axillary fan to cool it.

I have an old (1988) 3hp oil lube craftsman compressor that I've beat the snot out of, but I always change the oil, and used a fan to keep it cool. Now I have an industrial compressor and have several LARGE air tanks attached to my air plumbing so I have 300+ gallons of air storage.

If you have any other questions - please ask.

 

[Iplayfarmer]

Greetings Iplayfarmer,

Did you get the answers to your questions regarding scfm, ascfm, etc?

One thing you didn't post is what you might intend on doing with the compressor in the future. If you don't care, that's a mute point. When comparing specs on a compressor you want to compare apples to apples. Most cheaper compressors (what you are looking into) rate the CFM at a lower PSI than the better units. Also they rate the HP at PEAK not "real" hp. I agree what's been said regarding oiless.

Also check design and parts availability - if it's a concern for you. Some have no head gasket, some have disc valves vs reed valves.

If you get a compressor that is rated for 100% - see what they mean by 100%. I'm sure it's not 100% if the humidity is 90% and the temps are 110F.

You just need to figure out what your willing to live with to decide what to get. One idea for air storage is an old propane tank. NOT a WATER tank!!!!. Propane tanks are rated for at least 250PSI. If you keep your eye out you can find them at the dump, landfill, yards and get them free. I'm not talking about the 20 lb tanks - but say 100lb on up - that gives around 30 gallons of air. Also if you will run a compressor a lot - use an axillary fan to cool it.

I have an old (1988) 3hp oil lube craftsman compressor that I've beat the snot out of, but I always change the oil, and used a fan to keep it cool. Now I have an industrial compressor and have several LARGE air tanks attached to my air plumbing so I have 300+ gallons of air storage.

If you have any other questions - please ask.

I never did get answers to what scfm and acfm mean. If you know or have a a resource, please let me know.

As for the future, I don't know. I never thought when I bought my first one that I'd be painting with it or that I'd be running and impact wrench much, but I am. The future may hold a sand blaster or it may hold a plasma torch if they come down in price. I know I'd need a much bigger compressor to run a sand blaster or plasma cutter. If I hold out 'til I can get that big of a compressor, though, the one I have will be dead dead rather than just weak dead.

I am planning on using my current tank in tandem with whatever compressor I get to increase the storage. I do wonder, though... What's the advantage of having a lot of storage? If your compressor will only pump so much air, having more storage won't give you any more air in an hour.

For the price of the IR I'm looking at I can get a cheaper brand that has more horsepower and more storage. Would the oversized cheaper compressor last longer than a IR being used at it's full capacity?

 

[Bird]

I never did get answers to what scfm and acfm mean. If you know or have a a resource, please let me know.

SCFM versus ACFM versus ICFM Actual air compressor capacity (ACFM) versus standard air capacity (SCFM) and inlet air capacity (ICFM)

See if this will answer your questions.

For us non-scientific types, just the CFM rating at 40 psi (maximum for most paint guns) and 90 psi (maximum for most air tools) is sufficient knowledge.

 

[Dan69GTX]

Another source would be:
http://www.trident.on.ca/compressed-air-terminology.htm

As for the future - I believe Yoda said it best - "it's hard to see - always in motion the future is."

Yes, you are right - you get what you can afford when you need to get it - just make the best decision based upon your needs.

As far as storage. Cooler air has less humidity that will affect paint/ etc. So if you have more storage then at least the initial air will be cooler/better for equipment or the end result. Also if you need a lot of air in a short duration you have it - even if the compressor can't do it. But if you need more air than you have stored - yes you are correct, you are at the mercy of the compressor.

For cooler air have the inlet and outlet be different on the tank - if possible. So the air has some time to exchange heat. Have an old radiator (water to air for a house) plumb the air through it and use it to cool the air. Have extra metal pipe? - use it and run the air through it as a heat exchanger. Many ways to skin the cat.

If you need a lot of air - check farm auctions - sometimes you can get older compressors that are still serviceable for a decent price.

 

[Iplayfarmer]

I think that's where I'm at for now. I'm going to gradually save up for the target, which I think is going to be $300 to $400. In the mean time I'll keep my eyes open in the want ads, ebay, auctions, yard sales, etc. for something that meets my needs, and soon enough my budget and what's available will meet up and I'll have a bigger, better air compressor and the world will be a better place.

 

[kenmac]

Be sure to buy the cfm's you need .( cfm's are like horse power in a race car, you can't have too much )Some air tools body sanders & such require alot of cfm's. With a low cfm compressor ,Your compressor will never recover (while running) once you empty the tank. I think mine is like 26 cfm's at 100 psi & 23 cfm's at 175 psi. It will run several tools at once including my large glass bead machine( which uses alot of cfm's)I found mine just by google search air compressors. They shipped it to me cheaper than I could buy local about 2 yrs ago & have had no problems.

 

[hill]

These guys seem to have a nice product. Eaton Compressor & Fabrication Inc. I don't have one but I would consider them. We use a 10 horse Champion compressor at work, and I have a 4.5 horse 110v Big Red type at home, both over 20 years old. I would recommend either of them.

I like Eaton's approach. That they explain the true meaning of much of the terminology of air compressors and gives apparently straight talk about the decal specs found on most all of the hyped up chain store versions will probably earn them my business next time, at least to buy a new compressor to put on my 60 gallon tank. Mine's got it's own little soundproof closet that I built to size and I'd hate to have to redo it for an 80 gallon tank.

If you ever plan to paint using HVLP guns pay particular attention to the CFM's because those guns require a lot of air to provide the 10 psi output. Same thing for sandblasting and plasma cutting - lots of air needed.

The chain store cheapies seem to be doing everything they can to mask the fact that the pretty compressors with decals all over touting their specs simply don't provide much sustained air volume

Period.

This is true of the IR compressors found even in Harbor freight and many other places and sold as the best you can buy. They're not by a long shot. Ingersoll has another line for professionals or people who are tired of the glitz and BS and decide to look for a really good compressor. Not sure where you get those but it ain't Home Depot, Sears, or any of the like.

even if you don't buy an Eaton compressor read through their website pretty carefully Eaton Compressor & Fabrication Inc.

 

[Iplayfarmer]

I'm pretty impressed by Eaton. They talk pretty highly of their product, but their prices are really pretty good.

Does anyone out there have an Eaton? Has it lasted like they say it will?

How is their shipping cost?

 

[Iplayfarmer]

Well my budget and the available product met up sooner than I thought. The more I looked at Eaton compressors, the more I liked what I saw.

I went ahead and purchased their Contractor Professional Compressor today. A large part of this decision was the recommendations of some of you here. Shipping to me was $45.

I may end up buying something bigger later, but for now this will at least meet my needs. I almost bought their 5 hp unit, but it was more than twice as much money and less than twice as much air.

I may even try to hook my two compressors in tandem to give me a little more storage and a little more capacity.

 

[have_blue]

Well my budget and the available product met up sooner than I thought. The more I looked at Eaton compressors, the more I liked what I saw.

I went ahead and purchased their Contractor Professional Compressor today. A large part of this decision was the recommendations of some of you here. Shipping to me was $45.

I think the Eaton is basically this one:

HF Compressor

Maybe it has the HP kicked up a notch, but I think the compressor heads are identical. I have had mine (configured differently) for 3 years, and used it continuous 2 or 3 times, and it never got real hot. One time I used a small air hammer for 2 hours, and I guess the motor ran almost the entire 2 hours on that job. For the price, you absolutely can't beat it.

 

[Iplayfarmer]

New development:

I just picked up a 10 gallon pressure tank at an old farm sale. What's left of the labels leads me to believe that it was for refrigerant; R-12, R-14, etc.

I'll have to plumb some fittings to it, and then I'll have plenty of storage.

Now I just have to figure out how to plumb two air compressors and this extra tank so that I can use the one regulator that comes with the new compressor and not void the 2 year warranty that comes with the compressor.

 

[Iplayfarmer]

Now that I've been convinced through the collective wisdom of TBN that I need more air storage and I have followed the advice to seek out old junk tanks for that storage, I need some more collective wisdom as to how to use the junk tank for additional storage.

See the picture below. These are the fittings that I've got to work with. I'm hoping that someone will post back that there's some fancy trick that if I soak the fittings in cabbage juice during a full moon or something like that I can beat them off with a pipe wrench and end up with nice, clean, NPT threaded something that I can reduce down to the perfect size for attaching air lines.

Since that's very likely not the case, I figure the worst case scenario is to cut them off just behind the square part and thread the remaining pipe.

Is anyone familiar with this type of fitting? Is it likely I could take it apart?

 

[schmism]

Now I just have to figure out how to plumb two air compressors and this extra tank so that I can use the one regulator that comes with the new compressor and not void the 2 year warranty that comes with the compressor.

i did a simular thing. this is how i riged mine

i have an addtional 15 gallon tank i use on my little pancake.

I made a pigtail with 2 male fittings (about 16" long)

i made a T fitting with attached pigtail (i use as a regular 3 way) pigtail has a male and the other 2 ouputs of the T have females.

the extra tank has a female.

i also made a portable regulator with a male (in) female out (i can plug it inline anywere)

so

pancake output - pigtale on T fitting.

15 gallon extra tank - 2male pigtale to T fitting

out of the other side i plug the regulator in and a hose into the regulator.

any any time i can pop the extra tank loose as a protable air tank to use with a regular hose.

or pop the pancake loose to take to a job site and use with a regular hose.

 

[Iplayfarmer]

i did a simular thing. this is how i riged mine

i have an addtional 15 gallon tank i use on my little pancake.

I made a pigtail with 2 male fittings (about 16" long)

i made a T fitting with attached pigtail (i use as a regular 3 way) pigtail has a male and the other 2 ouputs of the T have females.

the extra tank has a female.

i also made a portable regulator with a male (in) female out (i can plug it inline anywere)

so

pancake output - pigtale on T fitting.

15 gallon extra tank - 2male pigtale to T fitting

out of the other side i plug the regulator in and a hose into the regulator.

any any time i can pop the extra tank loose as a protable air tank to use with a regular hose.

or pop the pancake loose to take to a job site and use with a regular hose.

Do you have a regulator on your pancake?

If so, do I understand correctly that the auxilliary air tank is down stream from the regulator?

I suppose that would work. Most of these regulators actually regulate the flow more than pressure, don't they? I.e. the auxilliary tank and the compressor tank will equilibrate to the same pressure eventually regardless of what the compressor regulator is set at. (As long as I'm not drawing air out of one or the other.)

 

[schmism]

Do you have a regulator on your pancake?

If so, do I understand correctly that the auxilliary air tank is down stream from the regulator?

I suppose that would work. Most of these regulators actually regulate the flow more than pressure, don't they? I.e. the auxilliary tank and the compressor tank will equilibrate to the same pressure eventually regardless of what the compressor regulator is set at. (As long as I'm not drawing air out of one or the other.)

yes i have a regulator on the pancake but i run it wide open, as to have no effect on the output pressure/flow rate.

Ive run the above setup for over 2 years now and it has been great. The only down side is my little HF (oil bath) pancake has run nearly contionusly for 10+ mins at times. (i have yet to see any issues) Ive had my pancake for near on 4 years with regular shop tool use. (no spay guns or air sanders)

 

[Iplayfarmer]

Nothing is simple with me it seems. I had another development in this saga that I thought some of you may appreciate.

I took my old worn out compressor and moved it back to it's "home" in the garage. The plan was to tinker with it a bit to bring the pressure setting down so that I could still use it albeit with a lower maximum pressure.

I turned it on and watched the pressure guage climb so that I could see about where it peaked out. (Previously it would just keep running without building pressure enough to shut itself off.) Low and behold it pressured right up and shut itself off. I hooked up a blowgun and ran the pressure down a few times to warm it up good and re-create the problem. (my workbench and cupboards are all completely dust free now)

It cycled perfectly at least a half dozen times without fail. I pressured up some tires and blew off a few more surfaces and put the thing away for the night. I guess it works now.

The new one is already on it's way to me by now I'm sure. I guess I'll have two working air compressors. No problem there other than the money spent. It will be nice if I can get them effectively hooked up in tandem.

 

[Bill_C]

You can hook up two compressors together, no problem, just tee them both into a common line. When you're using a low-demand item, you could actually only turn one compressor on, if it keeps up with the volume needed...then for higher demands, turn the other one on. (No need to close valves, just flip the electrical switch on or of for the second compressor)

Many factories will do exactly this, they will have several compressors teed into their plant's air supply header.

Worst case, if the air pressure leaks out through the non-working compressor, you simply put a check valve in the line at that compressor. A check valve allows air to freely flow in one direction, but completely blocks the air in the other direction of flow--so it will let air exit the compressor, but not flow back into it.

 

[bones1]

You could connect a pressure switch downstream and set it to turn on the backup compressor at a certain pressure.

 

[Bill_C]

Or, if the existing pressure switch on the backup compressor is adjustable, just adjust it so the backup compressor kicks on 10 or 15 psi lower than the primary compressor...

 

[travis potter]

At times I need lots of air so I'm building a Volkswagon air compressor it runs on 2 cyl and pumps on 2 cyl. A company advertises in VW Mag and sells the kit to convert a air cooled vw. About 45 cfm at 90 psi. I found mine at at an air compressor repair shop for $ 100.00 It was made in Germany.should be 100% duty cyl. A co. in the states used to build heavy duty compressors from 289 Fords and 427Fords run on 4 pump on 4. Just something to think about.