Technical Minimum size compressor for shop work?

To get more SCFM at a lower price, I use two compressors in parallel. Both 6 HP 240 volt, 2 stage, mounted on 60 gallon tanks. Each rated 10.2 SCFM at 90 psi. Used mostly for a Truman glass beading cabinet. It will work at 90 psi, works better at 120 psi. If doing fairly continuous work, the operator gets to take a break ever 10~12 minutes to reload the pressure. Have a second cabinet loaded with crushed walnut hulls for aluminum and zinc. Can really dial the pressure back on this one.

Compressors are rated 12.5 SCFM at 40 psi.

As others have said, look at your needs.

Truman says this cabinet requires 15 SCFM, and I have 20 which is insufficient for continuous work. But at my age, a break after 10 minutes is not a bad thing!

Too much air is much better than too little.

Cannot give advice on brands. Both mine are Craftsman, and at least 15 years old. No issues.

Jon.

 

Yeah me too, happens with other sites too.

 

I was at TP Tools in Canfield, Ohio. A person there was very informative on compressors. Low rpm, hi output will be about double the price of typical general use compressor. If you go on line, and find TP Tools, you'll see their compressors and compare.

 

I didn't read it all but likely the same advice above. Buy the biggest and highest CFM rated machine you can afford. Look to shops closing, auctions (big maybe there), and commercial rebuilders. CFM@PSI is important. 2 5hp compressors can have the same tank and hp but 1 is rated 18 CFM@90psi where the other is 18@150. It was years ago but I bought a 10HP 35CFM@150psi Speedaire from a shop closing with 2 tanks that equal 200 gal together. I added a 10hp single ph motor and all in I was about $1400. Catches up to 2 DA sanders running (!) and admittedly it's overkill for most. Now it's back on 3ph at the shop and still have the "family" Kellog 5hp at home now. It's pressure oiled and rated at either 18 or 21CFM@150psi, had it so long (1978) I forget. Still runs like new. BUY THE BEST YOU CAN AFFORD.

Big time names are Curtiss, Saylor Beale, Quincy, Speedaire, Kellog, Wayne and others. Sometimes commercial rebuilders sell top dog badass stuff at box store prices. If this sounds like a I'm a compressor snob, well I guess I am.

 

I said I was a compressor snob. Had this getup in my home shop (!):

10 HP Speedaire:

120 gal addl tank, now plumbed into the shop.

I only did this at home because I already had it. With the 1ph 10HP motor it gently flickered the lights in the house if I forgot to shut it off. 42amp start, 26amp run, but it only runs a minute 20 seconds to cycle from 125 to 150psi, to 200 gal total! From empty it fills 200 gal in 6 1/2 min. Even at the high amps it ran so little it cost less to run overall. The 1ph motor was a Grainger farm duty with the same frame and RPM as the 3ph it came with. Overkill for home? No doubt, but then again a blown 426 Hemi is overkill for a hot rod too, so I figure I just have a AA/AC getup, right? If I didn't have it already I'd have searched for a vertical 5 HP high CFM rig and only throwing it out as an example of what can be done if the right equipment shows up, which it sometimes does. About 9 years ago a guy was "stuck with" a 2 stage 4cyl 10HP Saylor Beall on a horizontal 80 gal tank. It looked lightly used, he had to "dump it" for $900 and was losing storage. I went to buy it a couple days later and couldn't reach him. When I finally did he had of course sold it. Didn't need it but that same machine retailed for about $5K. The deals are out there, just be patient AND ready to strike.

 

HIGHLANDER that's dang good on filling 120 gal tank.
I have a 5 H/P 2 stage Quincy 80 gal, takes it 7 mins to fill from empty to 175 PSI.
On a side note, if one wants to keep some of the noise down, you can pipe the intake air to the compressor to the outside or a different room.

 

That's 2 tanks, 80 + the 120 for a total of 200gal. I can run a pressure pot sand blaster with it, no issues. And actually it's not all that loud. I can converse without really yelling when we're in the room, but I keep the doors closed during work days.

 

This is my local C'list rt now, pressure oiled 1ph 5hp Kellogg for $1,200:

https://detroit.craigslist.org/mcb/tls/d/warren-5hp-120ga-air-compressor-for-sale/7092782742.html