The Stovebolt Site Forums The Shop Area The Tool Chest opinions on air compressor

I am thinking about buying a husky 7 hp 60 gal. 230 volt air compressor from home depot cfm is 11.8 @ 40 psi & 10.3 @ 90 psi. cost $399, anybody have one? what do you guys think? just going to use air tools with it. thanks James

That would be a good one. Should cover most needs. For the price it is hard to beat.

You can buy a single stage sixty-gallon Ingersol-Rand for the same money-and no sales tax f you find an out of state supplier that ships for free.

I have basically that same configuration in my shop. Plenty of volume unless you hook up too small a hose. I found that I could plumb in a manifold of 1" PVC and have plenty of volume even to run the less expensive air tools.

A couple 1/2" X 25" hoses work better for me than a 3/8" X 50'.

That's a good price!

PVC is not a recommended pipe for air systems. The air pressures can cause the pipes to break into many small shrapnel pieces.

I have to agree with MNSmith PVC is down right dangerous! Should use steel piping rated for pressure!

bigger is better if ya want to sandblast

what would be the minimum cfm &/or size if I want to sand blast?

James B,

Any kind of sandblasting uses horrendous amounts of air. The smallest siphon blaster Northern Tool lists uses 7CFM @80 psi. That almost maxes out your new air compressor...pretty scary.

Your compressor choice was great. To do the occasional blast job, the drill would be to blast a little, and wait a little! This will work, but you have to keep an eye on your compressor because if you grossly exceed its duty cycle, it will cease to exist.

Northern Tool shows a neat pressure pot that holds 90 pounds of sand. Using a 1/8" nozzle (dinky) this thing still eats up 15 CFM @ 80 psi. Are you starting to see the picture on sand blasting.

Stuart

I understand if you sand blast you will eat up a lot of air, maybe I don't understand the cfm @ psi thing, can you explain it. thanks James

James B,

Sandblasting demands a high volume of air. The "hole" in the end of the hose is huge. To do an effective job, you need lots of sand moving at a great speed.

A air compressor needs a large displacement to move a large volume of air..cubic feet of air!

Because there is no free lunch, the large displacement compressor needs a large source of power, whether it be a electric motor or diesel engine.

Take a straw and put a pea in it. Blow the pea across the room. How much lung power did it take?

Take that same pea and lay it in a empty toilet paper roll. Blow it across the room. Big difference. You need more CFM!

If you plugged the ends of the above examples and blew into them while recording the pressure, they would be identical..PSI, no big deal, CFM, big deal.

Stuart

o.k. I got it thanks for the info. I was also thinking of getting the huskey 80 gsl 12.6 cfm @90 psi 2 stage 7 hp for $699

jamesb, tptool has a good read on their website about air compressors etc. Of coarse they want to sell you one but its good reading. A good rule of thumb is to have TWICE the capacity that you need. Believe me you will need it. If not now later! Also you need about one third more CFM than you plan on using. This way you can really WORK on something. I used a small 20gal 2Hp for long time and saved my money. Now I have a 80gal 175psi 19.7cfm. I run the sandblaster, bead cabinet and lots of air tools and it really does the job. Of coarse at 800 bucks its a bit pricey but man, its been a blessing these days. I guess the bottom line is what you can afford and what your long range hobby plans are. Surely when you get this one done you will start another.

Buyer beware...there is a lot of fraud in the market of air compressors. There are companies claiming more CFM than what their unit actually has. The way to check for this, get their PUMP-UP time in writing and this will cover you if they have a fault CFM. Things to watch out for: fast pump RPM--low RPM is better, compressor companies are giving you "starting" HP instead of "running" HP, which means NOTHING when purchasing a compressor. To be a TRUE 5 hp motor, it must pull at least 23 running amps or it is not a 5 hp motor. Compressor pumps that are claiming cast iron and they are really not. When shopping take a magnet with you. If it doesn't stick, it is not cast iron. Watch out for reed valves. They are a cheap valve system.

I swear by these compressors. Check out this site:

http://www.eatoncompressor.com/catalog/item/504747/206953.htm

I got a 18.5 cfm at 100 psi 3 cylinder with one of those bogus small frame "5hp" motors. Fine for some work but won't keep up with blasting.

Builder that is a nice one on that site and a good deal.

Check out Tractor Supply,they carry the IR compressors at a decent price.I bought one back during the holidays when they had a 10%off sale.Its an 80 gal.5 horse,2 cyl.2 stage compressor,which should handle most of your needs including sandblasting.Regular price was $995.,with 10% off I got it for about $895.I dont know how often they run the sales on them,but it is worth lookin into.

11.8 @ 40 psi is barely enough for a spray gun. It would have to work so hard, you'd be shooting as much water as paint. If you've ever priced electric motors the $399 would have tipped you off. You can't touch a real 7 horse single phase motor, just by itself, for twice that price.

SWITCH to a lphv gun, (lo pressure/hi volume) 11.8 @40 will work great.

Come on now, the EPA wants us to get away from that.

It's usually written HVLP. The High Volume part of that means just that, High Volume.
Here is a Sparpes web page that shows the requirements for their guns.
The gravity feeds need 13.5 CFM @40 and 13.9 @ 50 psi
Sharpes

Check into LVLP guns for less air consumption. I have heard good things about them.

[QUOTE]Originally posted by Richard:
[QB] It's usually written HVLP.
Sorry Richard, I have the gun, just too lazy to go out to my shop to see which way it was written. wrong guess.

The air compressor you are talking about is way too small for any type of blasting.

Look at the site I listed below and read some of the descriptions of the air compressors. There is a lot of information to keep an eye out for.

Mat, the CEO, will also be happy to discuss air compressors personally with you if you call.
http://www.eatoncompressor.com/page/page/504413.htm

I bought an Eaton, and wouldn't hesitate to buy one again.

If you have air tool's then the compressor is the heart. As was mentioned above pump RPM is something to look at, a lot of manufacturers make up CFM by spinning the guts out of the pump and that will cut down on longivity. Look for a true cast iron compressor, two stage with at least a true 5hp motor with a rpm of 1750, pump speed is 546 rpm. Mine is 80 gal, 5hp, 1740rpm (Leeson motor), 18.4cfm @ 175psi,( it is a horse). In 1996 it cost $1050.00, got another one for my other shop in 2005 $1150.00, same rig, the owner of North Central Air out of Downs Ks. said that it was his best selling unit for small shops and farm use. To be truthful with you all I went to the bank and borrowed $1500. in 96 and got the compressor and a 100lb pressure sand blaster, for around $80 bucks a month for a couple of years. Was the best investment I ever made in shop equipt.My advice is buy the best compressor to do the job even if you have to finance it for a while, it will outlive the inexpensive one time and time over.

I am about to buy a 7.5 HP compressor. Have been looking at Ingersoll-Rand and Eaton. As my use won't be extreme I am also thinking about the machine Harbor freight sells. I know it is not as high quality but is several hundred dollars less. Anyone have one of HF's machines this size?

harbor freight - ~$450...

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We have a place called tractor supply (TSC) that have verry good prices on compressors

Bought the I-R 7.5 HP compressor. I am familiar with Tractor Supply and checked their price online but they do not have a store near where I now live. Bought it from local I-R dealer for a little more money. Hooked it up Wednesday. It's no quieter than my 5 HP but not bad and pumps a lot of air. Wil give it a real test on my sand blaster rig this weekend.

If noise is a factor or just a irritation you can get a muffler for it, I have one for mine (got it from the dealer I mentioned above) for about $80.00 and I can talk on the phone next to my compressor.

I have a Curtiss 7.5 HP with baldor motor rated at 23CFM at 175 PSI never runs out of air. We run a farm shop and use a lot of BIG airtools. We use a 1" Chicago Pnuematic air gun on semi tires and use DA's quite a bit never have to wait for it or run out of air. Bought it through our local electric motor repair shop. They also handle IR but recommend the Curtiss for more continuous duty and it was cheaper than the IR of the same size. Check it out!

I have an Ingersol Rand 80 gal, 5 HP, twin cylinder that puts out 18.1 cfm @ 90 psi & 21 cfm @ 40 psi continuous output. Max psi is 135. I hard piped it around the garage using 1/2" black iron pipe. I got it at Tractor Supply and LOVE it!! It's some of the best money I've spent.

Got my I-R 7.5 HP piped up and running. Used it with my blast cabinet and pressure pot over the last couple of days. Even builds up and shuts off while blasting. Not sure what size nozzles I have in either blaster as it has been a long time since I bought them but it removes a lot of paint/rust pretty quick. This may be over-kill for what I need but it sure is nice.

JJ,I looked at the 7.5 IR,and it is truly a nice compressor.However I didnt want to spend that much money on one.I settled on the 2 stage 5 HP model,which I think will servre my needs.I am sure that 7.5 will treat you just fine.

heavy duty pvc. is rated at 480 psi ive seen it used at boat yardes i have a pipe running from my house 200 feet to my shop its underground works fine for me running 150 lbs. only trouble they had at the boat yard was the fence getting bumped then the pipe would get broke but was easy to fix another thing i did was hook up a 2nd 80 gallon tank to my compressorfor more air storage