Big Quiet Low-Budget Air Compressor

Keith Tanner said:

So Jumper's scroll compressor has me wondering if you could take a supercharger and power it electrically to make a quiet compressor. The pictures make me think of the G-Lader. Who's up for it?

Hmm....  I have a used R53 supercharger... 

I think with an automotive supercharger, you'd need two of them in series to get the pressure you need.  All the big industrial compressors these days are twin-screw (lysholm) and they all have 2 stage compression.  Here's a picture of the primary and secondary screws of a big compressor that's disassembled. 

I have been collecting together a bunch of A/C compressors from my various engines, and they seem to be very different.

I have one that puts out a lot of air spinning it by hand, another one that puts out a little bit, and three of them don't seem to do anything spun by hand (and yes I spin the compressor not just the pulley)   I am wondering if they have some kind of bypass valve that needs energized to actually work, besides the magnetic pulley.

I don't think so,  but there is some kind of electrical thing on the ones that don't seem to work, which I'd assume was just a pressure sensor, but is it something else?

Now watching this video for a passat compressor (which is one I have), it says there is a solenoid to turn it on/off, so that must be it??  It has that AND a magnetic pulley?

Brett_Murphy said:

My brother-in-law works as an installer for industrial sprinkler systems. It came to my attention that they get working but deprecated air compressors all the time. I dropped him a note and he's going to try to set one aside for me for when I go visit in July.

I'm going to need a tank. I'm thinking 40 gallon or larger. I see that Northern tool, Lowe's and the other retailers have plenty of smaller, portable tanks, and then they jump up to like 200 gallon tanks. Besides looking on Craigslist and in FB marketplace for compressors with good tanks and bad power units, where can I find a tank? 

 

Junk yard for heavy duty trucks.  

Get a few air brake reservoirs, mount them in the attic or rafters.

Got a free tank. No idea if it will hold air with a bit of refurb or if it will wind up being a giant meat smoker.

In reply to pjbgravely :

I did that with a fork lift muffler

Keith Tanner said:

So Jumper's scroll compressor has me wondering if you could take a supercharger and power it electrically to make a quiet compressor. The pictures make me think of the G-Lader. Who's up for it?

I had most of a G60 charger somewhere around the house...

I run a Husky 30 gallon oil-less unit and it isnt terribly loud. It was $309 on sale at Home Depot and replaced my old oil-less Craftsman 25 gallon.

Here is a picture of my setup. PS, if you get a chance, the Dewalt air hose reel is worth every penny.
 

This caught my eye, and its easy enough to get 10% off coupons for Lowe's putting this at $243 before tax.  Obviously not going to match a 220V Two-Stage for airflow but seems to be good enough for general use and spraying.  

https://www.lowes.com/pd/kobalt-quiet-tech-26-gallon-portable-electric-vertical-air-compressor/1000405189?cm_mmc=shp-_-c-_-prd-_-tol-_-google-_-lia-_-153-_-compressorsdiyandstationary-_-1000405189-_-0&kpid&store_code=1823&k_clickID=go_1736136440_66323254485_338417530440_aud-299487635210:pla-436698074635_c_9016990&gclid=EAIaIQobChMI_O396brz4gIVikkNCh0fpQftEAQYBSABEgKm1_D_BwE

If you really need more oomph, seems like the way to go is to find a used 220V american made two-stage, and put it in an outdoor enclosure, solves the "quiet" part of the cheap, quiet, airflow equation.

Keith Tanner said:

So Jumper's scroll compressor has me wondering if you could take a supercharger and power it electrically to make a quiet compressor. The pictures make me think of the G-Lader. Who's up for it?

Kinda like this?  Wisconsin engine hooked up to an old GM Diesel blower.  It supplies compressed air (and vacuum) to our calliope  

A supercharger doubt they can produce 140psi, just not sealed well enough for that kind of pressure.

And they make a pretty loud whine too. 

I think an A/C compressor is the way to go.  I have about 5 of them, just need to find the time to build the thing.

I think the only viable automotive AC compressors are the old York type.

In reply to engiekev :

I thought sprayimg required a lot more CFM.....  I probably need to learn soon.

bentwrench said:

I think the only viable automotive AC compressors are the old York type.

Yorks are ideal for this use, but the Sanden type compressors can work.  You just have to feed a little oil into it and then separate it back out of the air after to get a good lifespan out of it.  

iceracer said:

In reply to pjbgravely :

I did that with a fork lift muffler

Good idea, I never thought of doing that. I will try it when I get a bigger compressor for the garage.

Woody said:

Look for a used Jun-Air dental compressor. I have two. New ones are crazy expensive. Dentists need to replace them every ten years or so. Mine are so quiet that I thought they weren't working until I saw the pressure gauge moving up.

 

 

I've been looking for one of these to customize for the theater.  I was going to put maybe four compressors on a large tank and plumb air everywhere, but in three years (since I first saw you post about them) I've not found a single used unit.  Do you have a magic source where you find them?

Well... that's not true.  I've found them, but not in GRM prices.