Shop air dilemma

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I hope that is a typo on the specs. 5cfm would barely run my cutoff grinder.

5CFM@175PSI is pretty good. It's the tank capacity that's the deal breaker. Most compressors are CFM rated at 90PSI. That one is rated at 175PSI. Big difference. Put a 60 gallon tank on it and you got somethin.
 
I see some good advice above but the "King" of compressor specs for blasting has only been casually hinted at a few times-

CFM, CFM, CFM.

CFM is the king, almost nothing else.

Gallon capacity can be zero. PSI can be 75.

HP does factor, but again-

CFM, CFM. CF'n M!

I'd advise to get the highest CFM@90 240V unit you can afford.

...and I'd also advise at least 15-20 CFM@90.

Usually it will be a 5HP or more motor, and a 60-80 gal tank.

Don't shy away from a smaller tank. The CFM will more than make up for it.
 
Most I see that are rated for CFM at 90 PSI are single stage compressors, and max out around 120 PSI. A 2 stage compressor is usually rated for CFM at 175 PSI and are set to cut out right there.
 
A smaller engine would be great
Smaller than what?
I have a few old kohler cast iron engines around, and an 18 hp opposed twin too. I wouldn't mind finding a big enough compressor to drop one onto that would eat up all the HP whichever engine I wanted to use, would eat up my 5 hp gas one would be a decent paint/spray rig I think, or great for airing up tires. It barely handles my 1/2" impact. My 8 hp gas one is a little better, faster recovery time than the 5 hp unit but a little smaller tank too. I'd like to find a 2 stage compressor with a dead motor and an 80-120 gallon tank that I could put one of my heavy old kohler engines onto. When looking for a compressor it is rare to hear someone say that theirs is too big,and when you do usually it's a "not enough space" issue more than "too much air for my needs".
 
My set up.

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IIRC, the largest single phase motor you can run on 240v is 10 hp. If you can't/don't want to go that route, a 16 hp horizontal shaft gasoline engine is in the ~ $400 range. So depending on how much hp you need, you have options.
What I was going to suggest. I’ve seen a few that will really put out the air on the tire changing trucks for BIG equipment vehicles, busses tractors and the like.
 
I need that inline air drier. Bad. One for home and probably a couple for work, because of the length of the lines after the compressor
Yesterday I was changing tires on a triple axle trailer and twice in the time it took me to unbolt and bolt on 6 tires I had to stop, unhook my gun, and stick a male adapter into the coupler and just let the air run after my $600 snap on impact started spraying water like a faucet. I'm getting tired of that especially when work don't buy my tools or pay when they need sent out for rebuilds. I do go thru alot of air tool oil as well.
 
Unless you have a real reason for wanting 3 phase, I'd reconsider. it's not required as many have said and the cost of the extra line is probably a waste. I do have a friend that uses some pretty bad *** woodworking tools so your mileage may vary. Beyond that, I'm not sure what "car related tools" I would ever use/need that might require 3ph. Maybe a big lathe or mill I guess.

Large volume, big pump and CFM is your buddy. I run my blaster, a modified unit that looks like a HF unit, but is not, all day long. You don't need that much pressure for a blaster usually and media flow is probably more important. Is in my case anyway.

Even a 60 gal, 2 stage would be good. Bigger units run quieter though. I can talk with barely a raised voice (by my standards) while standing next to my 80 gal, 5hp unit.

Something to keep in mind, those 110 units where they say it's 5hp, aren't. It's not possible to get that much power out of 110. At most they are around 3hp. Does it matter? Not particularly, lots of people paint and blast with a 60g all day long, it will cycle more that's all. more cycling, less life.
 
115 volt about 3 horse. 220 and 7.5 horse is the limit. 3 phase probably 15 horse or more. Most automotive tools are rated (rpm or power) at 90psi. Like many have mentioned, volume is your friend. The 175# ratings are just to get the numbers up and make them more impressive to the unknowing consumer. 175# of air through a die grinder that spins 20,000 rpm @ 90 psi is a hand grenade. Think about that. A sand blaster will use the most air in your shop.


That's a very important point. People forget that although the tank may support having 175 PSI, you're tools won't. All the higher pressure does is allow you to squish MORE air in and thus cycle less. More pressure means more air in the same volume of space, that's it. And you're not usually going to push the tank that hard anyway. Mine is rated for 175, but the cutoff is set to around 145. Tanks are tested hydrostatically to about the rating +30% as I recall. They test that way because it's not a violent failure. A compressor tank failure that's been over fullre is an EXTREMELY violent failure and you don't want to be anywhere near it. i wouldn't want to be in the building at all.

Also, and I know someone will say "but I did it for 400 years"... do NOT use PVC of any kind to run air. A single failure will grenade and throw sharp *** shrapnel across your shop and possibly into you. Facts is facts...
 
My 5HP 32 CFM unit runs constantly if I'm blasting.

Constantly.

The 80 gallon tank is exhausted within the first minute.

That is why pump CFM always, always, trumps gallon capacity.
 
My 5HP 32 CFM unit runs constantly if I'm blasting.

Constantly.

The 80 gallon tank is exhausted within the first minute.

That is why pump CFM always, always, trumps gallon capacity.

Great googley moogley what the hell are you blasting? lol
 
There are some standard RPM specs for continuous duty electric motors.

I want to say 900, 1500, 1800 and 2400.

The lower the RPM, the quieter.

However, most lower end to mid range compressors in the 5 HP and 15-20 CFM range tend to use higher RPM motors.
 
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Great googley moogley what the hell are you blasting? lol

Really anything.

If you've ever blasted anything larger than a PS bracket, that's just the way it works.

That's why I preach CFM.

Anyone who thinks they're gonna get a 3HP 8 CFM unit (even if it has two 120 gallon tanks) and blast anything successfully will be sorely dissapointed.
 
Really anything.

If you've ever blasted anything larger than a PS bracket, that's just the way it works.

That's why I preach CFM.

Anyone who thinks they're gonna get a 3HP 8 CFM unit (even if it has two 120 gallon tanks) and blast anything successfully will be sorely dissapointed.

Huh, mine doesn't do that. I run about 40 or 50 psi at the blaster. My compressor keeps up just fine.

CFM is important, but air doesn't get the job done, the media does. If the air aint delivering the media, doesn't matter how much CFM you have.

I use a metering valve under mine and it's night and day.

You probably have a commercial unit and it may already have one, but in my case it was an amazing improvement.
 
Mine is set a 130 psi but I occasionally add a regulator at the cabinet for 80.

I'm using real sand as most of the stuff I blast is caked in dirt/grease, even after washing and it gets expensive to keep replacing quality media and time consuming to thoroughly de-crud before blasting.

I just let the blaster do the work.

Most commercial sand blast equipment doesn't even have tanks.
 
Mine is set a 130 psi but I occasionally add a regulator at the cabinet for 80.

I'm using real sand as most of the stuff I blast is caked in dirt/grease, even after washing and it gets expensive to keep replacing quality media and time consuming to thoroughly de-crud before blasting.

I just let the blaster do the work.

Most commercial sand blast equipment doesn't even have tanks.

Ah well that explains it a bit. With my setup though I put about 6 cups of media in and go to town. The metering valve us a godsend. I'm never in a hurry though since I don't do this for a living and just rely on de-crudding first.
 
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Unless you have a real reason for wanting 3 phase, I'd reconsider. it's not required as many have said and the cost of the extra line is probably a waste. I do have a friend that uses some pretty bad *** woodworking tools so your mileage may vary. Beyond that, I'm not sure what "car related tools" I would ever use/need that might require 3ph. Maybe a big lathe or mill I guess.

Large volume, big pump and CFM is your buddy. I run my blaster, a modified unit that looks like a HF unit, but is not, all day long. You don't need that much pressure for a blaster usually and media flow is probably more important. Is in my case anyway.

Even a 60 gal, 2 stage would be good. Bigger units run quieter though. I can talk with barely a raised voice (by my standards) while standing next to my 80 gal, 5hp unit.

Something to keep in mind, those 110 units where they say it's 5hp, aren't. It's not possible to get that much power out of 110. At most they are around 3hp. Does it matter? Not particularly, lots of people paint and blast with a 60g all day long, it will cycle more that's all. more cycling, less life.
All the machines in my ‘work’ shop, not home shop, are 3 phase, efficient and powerful. My power bill runs from $40 to $75 a month smallest motor is 5 hp biggest is 25 hp. My 80 gallon 5hp compressor will pump up from zero to 150 in 3-1/2 minutes (47 years old and still has original oil in it) My 5hp (single phase) Emglo 80 gallon at home takes way over 6 minutes. 3 phase does make a difference
 
There are some standard RPM specs for continuous duty electric motors.

I want to say 900, 1500, 1800 and 2400.

The lower the RPM, the quieter.

However, most lower end to mid range compressors in the 5 HP and 15-20 CFM range tend to use higher RPM motors.
Everyone I’ve seen are 1750 or 3400. 1750 the more powerful at the same hp
 
I too blast alot of small parts and my old CompairKellog 5hp was just worn out. It was only made for three years, mine was a1984 and there were no parts available to rebuild the pump. So i did some research and bought a 5hp 80 Quincey. To which i have been very satisfied. I cycles on and off while I’m blasting. Another addition to my blaster in the last month is a Eastwood dust collector. I have been very satisfied with it.

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All the machines in my ‘work’ shop, not home shop, are 3 phase, efficient and powerful. My power bill runs from $40 to $75 a month smallest motor is 5 hp biggest is 25 hp. My 80 gallon 5hp compressor will pump up from zero to 150 in 3-1/2 minutes (47 years old and still has original oil in it) My 5hp (single phase) Emglo 80 gallon at home takes way over 6 minutes. 3 phase does make a difference

Didn't say it didn't make a difference. Most homes are not set up for three phase power, so there is an added up front cost. The equipment costs more as well. It's not as simple the running cost. For a home shop, it's overkill unless you're making money and the 2 minutes it takes to fill int eh morning makes that much of a difference. Again, if there are other machines that use 3ph, by all means, knock yourself out. I wouldn't bother though
 
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