Air Compressor

[73novaguy]

What is the best bang for the buck when it comes to an air compressor! I am looking in the 600$ range! A little more, a little less! Just for the typical weekend wrencher! Some DAing, impact wrneches, cutters, grinders, and all other typical air tools! Lookin for a stand up, but not mandatory! And what have you guys used for lines in the garages? I want to run prolly 4 or 5 drop downs. Any and all suggestions welcome!!!!!!

[Ralph LoGrasso]

I went with the craftsman professional 60 gallon oil less compressor. It's 175psi. Craftsman's compressors have a rating on them for usage, from 1-9, this one is a 9. However, it's very loud, I might have gone with a belt driven compressor had I heard it in my garage first. It also requires 220, and you have to do some electrical work to wire it up.

[parsonsj]

I followed Campbell-Hausfield line recommendations:

1" main supply line to the shop and garage. 3/4" branch lines (going up from the main line if possible to keep water out of the branches) to a trap with a drain, then a water trap, also with a drain, and 1/2" outputs to your rubber or neoprene lines.

I use full size ball valves to isolate branches to drain them. I have 4 branches right now, and stubs for another two.

I did it all with Type L or M copper tubing (whichever has the thicker wall of the two). All supplies from Home Cheapo.

jp

[DLinson]

Check out the air requirements for the tools you plan on using and make sure the compressor can keep up. The tool should be rated something like "2.4 CFM at 60 psi." Check out what the compressor output is rated at. I have a single stage Devilbise 60 gallon upright running on 220. It will keep up with most tools but it won't keep up with my 3" cut-off tool or my inline sander.

If you can find a dealer around you that refurbishes air compressors, see if they have a rebuilt 2-stage 60 gallon upright. This should handle everything.

Get a water seperator. I have a seperator that uses a roll of toilet paper to absorb the moisture. It works pretty good and has to be changed about once a week if I'm really working the compressor or if I'm spraying paints. I got it from a body shop supply store.

I built a small addition onto the back of my garage for storing the lawn mower and bikes. I also put the compressor in there and it really cut down on the noise in the garage. My friend put his in his basement and ran the supply line up to his garage. Not a bad idea seeing how the air in the house is lower in humidity due to heating and air conditioning. He also has a 2 stage which runs quieter than a single stage. They run at a lower RPM.

I used schedule 80 (grey) pvc line for my system. It's working but found out after I put it in that it's a real no no. Apparently plastic wil be prone to rupture after cycling on and off the pressrue after a while. It's been in there for 6 years now without any problems. Next time I'll be using either copper line or gas pipe.

My hand is cramping up. I'm going to stop typing now.

Good luck,
Dennis.

[73novaguy]

Thanks guys for the recomendations. Parsons J... Did you just go through and sweat the joints in the copper like you would for normal water useage in the home? What kind of rating are we talking about when using copper for PSI? Will it handle 190 PSI? I am lookin into the Sears Craftsmen Professional, with the 80 gallon, 7 HP motor! It is basically the same as what Ralph is running excpet higher SCFM ratings for continous use tools! What do you think Ralph? I could buy the one you have and put it outside the garage for noise purposes, but in Wisconsin, it gets a little chilly in the winter months! So I wouldn't want to put the motor under that kind of stress! Could you maybe build a box around the air compressor that is filled with insulation and an access hole to cut down on noise and still be able to access the controls withouit having the remove the whole box. Of course you would need some sort of ventilation! Just curious cause the 80 gallon is right in the 900 dollar range and I didn't want to spend that kind of money unless I NEEDED to. Keep the comments coming guys! I love hearing about other guys garges for ideas of my own!

[68protouring454]

i would buy a 10 year old 2 stage 60- 80 gal way before any of those craftsmen oilless, or for that matter oil compressors, unless you get into there 5 hp belt driven compressors, they are way to loud, my 7.5 hp 2 stage is loud but not like those ones, once you use a 2 stage with a cut off tool or da sander you will never go back to a single stage, you should be able to buy a real nice used 5 hp 2 stage, ingersol or bel-aire for around 4-6 hundred bucks, my father bought a rebuilt 5 hp 2 stage ingersol ran t-30 for 800 with warranty, i see them alot in local ad's for 500 bucks, i would buy one of these, it will need 220 power, and the 5 hp are around 22-25 amps, that is what the motors are at start up, so wire in a 30 amp breaker and some #8 or #10 wire you you are good to go, i would seriously look at this avenue, just make sure you can see compressor work and build air pressure, but you will know where the guy lives anyway if something happens, just make sure to be ready to hook it up as soon as you get home, that way you got a chance, theres not much to go wrong with a compressor, generally the pumps will be fine and the electric motor will die, a 5 hp motor is around 2-3 hundred so its not to mbad, goodluck
jake

[parsonsj]

Did you just go through and sweat the joints in the copper like you would for normal water usage in the home?

Exactly. The 1" tubing is a lot easier to sweat if you step to the yellow can (insterad of the blue propane) since that makes a hotter flame. The M or L tubing is rated at 250 psi in annealed (after sweating) state, if I remember correctly. The ball valves are rated even higher than that.

It's been in place for years now, no problems to date. One final note: be sure and isolate the copper tube from the compressor with flexible line. Otherwise the vibration would likely lead to a failure of the sweated joints near the compressor. I used Aeroquip 12 AN push-on hose and fittings from the compressor to the copper tube.

I also run two compressors in times of high demand (like when my buddy comes over to use my blasting cabinet while I'm grinding or something). I use an isolater (or one-way valve) to keep the higher rated compressor from filling the lower rated compressor beyond its rating.

jp

[73novaguy]

Alright, well how bout this. I have a freind who has a 60 gallon horizontal tank and compressor that I could get for next to nothing ($75) it is a 2 stage compressor but it needs a motor. Is it worth going through the effort to get a rebuilt motor for this setup. the brand of the compressor is Marathon (I've never heard of em) and it used to be an industrial compressor which ran on three phase! Could a regular 220 motor work? He said the motor mounting plate is drilled for various motor hook ups! What do you think of that? Knowing what I know about 220 motor and 3 phase (which is nill) I am gonna need some help on this!!

[68protouring454]

i would hop on that deal, you can easily mount a single phase motor onto the plate. the only think i would do is buy a good rebuilt or new motor, and all you will have to do is match the rpms the motor runs, that is important, most all the same hp motors have the same shaft size, but look into that also, i replaced the ones on my fathers for him awhile back, i got a brand new ge motor out of graingers for 245 bucks, it is a 5hp motor, if this compressor has a 7.5 hp or different it will cost more, but it will be worth it, goodluck
jake

[73novaguy]

Well it looks as if I am going the way of the old. The 60 gallon tank with 2 stage compressor and I am getting a 7.5 HP motor rebuilt. Now comes the question of pulley size? Because the old motor was a 480 three phase and the new would be a single phase 220, the pulleys are gonna be diff. the pulley size on the compressor is 17 and a 1/4". So what size does a guy need to run on the motor? The guy down at the local refrigeration and electric shop (where the 7.5 HP is coming from) said I would have to experiment and measure the amps coming from the motor to determine the right size pulley, but I was just curious if anyone knew if a conversion chart for this or what size pulleys they are running?????? I hope 68protouring454 has some suggestions because he seems to be pretty knowledgable in this dept. If anyone else knows, fell free to chime in!!!!!!

[73novaguy]

Alrighty, well I posted that the compressor pulley was 17 and a 1/4", but that is actually the size of the motor pulley (from when it was 480 three phase) And the motor being built is indeed the 7.5 HP with a RPM rating of 1750. Help? Thanks guys!!!!!! All of your knowledge overwhelms me at times!!!

[CarlC]

I could not agree more with Jake. A used dual-stage 60-80 gal tank compressor is far and way the best option for the very serious home wrencher. I bought mine for $125 from a lady who was divorcing her husband. I bought an engine stand for $5 also But, it took me two years to find that deal.

Compressors that are rated at 7 hp for residential use are not intended for continuous use. Craftsman (they don't build them) got sued and lost in court on the HP ratings of their compressors. There's a reason why the biggest, baddest single-phase 220 residential motor is rated at 5hp continuous. The electric meter spins REALLY fast when when my compressor kicks on.

Also, I would not spend the money for a rebuilt motor. To properly rebuild any standard NEMA frame electric motor under 15-20 HP is not cost effective. For example, you can buy a continuous duty 5 HP motor for around $250, and its American made. Grainger and McMaster Carr have them in stock.

The key to retro-fitting is the NEMA frame size. Both Grainger and McMaster Carr list the NEMA frame and shaft size for the motors they sell. The NEMA frame size is a set of standard dimensions for the mounting plate and output shaft. The old motor should have a data plate on it that has the NEMA frame number on it. The data plate should also list the motor HP rating and speed. Find this, and both pulley diameters, and we may be able to come up with a proper motor and pulley that will work on residential power.

I have a dual-stage 80 gal in a water heater enclosure behind the garage. In the past when doing head porting I took the door off and set a box fan in front of the pump to help keep things cool. This past February, since it was cooler, I tempted fate, and roasted the motor. If you keep the compressor in an enclosure, and know that it will be continuously running, be sure to remove the door and use a box fan to improve circulation. It was an expensive mistake.

My friend has a "5" HP Craftsman oil less compressor in his garage. It's no fun being in there when it's running. My ears are ringing when that thing shuts off.

[68protouring454]

73, as far as the pulley goes that sounds awful big for the electric motor side, most i have ever seen the big one is on the compressor motor side and there is a small 6-8 inch one on the electric motor shaft, some have one belt, most have 2, do you have pics of compressor and 3 phase pulley?? i would mic the pull ID and find out what the shaft size is, it's gotta be close to a single phase same hp motor, you did say the 3 phase motor was 7.5 hp?? and i agree with carl that a new motor is better than rebuilt, but as long as guy stands behind motor it should be ok, but it should last 8-10 years with medium use in a home garage that uses it weekends and weeknights, let us know
jake

[73novaguy]

Does anyone have any pics of there setup for the water trap. I am still not quite sure of where to put the water trap.

[68protouring454]

most big compressors have 3/4 npt output, i would put a peice of pipe 6-10 inches long in then screw a regualtor/water seperator onto it, then attach air line to that, if you are going to hard line entire garage, use a flex lin from compressor to peremanate mount seperator/regualtor on wall, then feed hard line, also the best is to have an automatic drain water seperator at compressor, then flex line to wall hard line (to take vibrations out of line) then run hard line to different stations and have sperators/regualtors at each station so you can adjust air pressure for job and tool you are using, goodluck
jake

[73novaguy]

Well guys. I know it has been awhile, but this has been an ongoing process of the air compressor kicking my butt. I went with the older Ingersoll-Rand 2 stage compressor that I picked up for 50 bucks, and then had a guy in town build me a 7.5 hp motor for it. After tinkering with different formulas to get the right size pulley on the motor I thought I finally had it figured out. So I strap the belts on and hit the breaker (30amp) and it runs for about 2 seconds. I thought maybe I didn't flip breaker all of the way. So now I only have 10/3 ran from the house to the garage and the max amps on the wire is 30. So 40 amp breakers are out of the question ulness I dig up 200ft of 10/3 burried wire. I tried opening the valve in the compressor thinking it will draw less and maybe get it up and running. Same 2 seconds as before! So i took the belts off the motor and it runs great! The motor will hardly draw any current by itself, but as soon as I hook up the compressor (which seems fairly easy to turn over) it pops the breaker! Any suggestions? Ditch the project, get my money back and buy a newer setup? I'm just flustered is all! I am not in a huge hurry to get a compresor cause i have no need for air tools at the moment, but an another month or two I def will!

[68protouring454]

are you sure the compressor you got had a 7.5 hp onit? also on tag on compressor it should say what rpms it should spin, and on the new motor you bought you should be able to see how many amps it needs to run, on startup is when it uses max amps after starting it drops back down, i am gonna say for a 7.5 hp motor it is around 32-35 amps, so yeah you need a bigger breaker, you might have wanted to check amp rating on motor before wiring it up, also burying 200 ft of wire there will be a decent amount of amperage drop, i would size the wire up 1-2 sizes big going that far, let us know
jake

[derekf]

I seem to remember reading something about a "starter" for larger engines like that - basically it's an electric device that goes inline on the wiring and will help the compressor get spinning when it would normally draw too many amps.

Not too sure on the specifics, as I kinda skimmed over the details.. but it might be something worth looking into.

[73novaguy]

Yes, the motor plate says that it is a max 36.6 amps. So I assume that the motor is pulling full amperage at start up. But there in lies the problem! I have 10-3 wire to the garage and I should have 6 or 8 running to it. Is the cost worth running the wire to this ole compressor (and when I say old the motor was here when Columbus arrived and the Indians before that made the air compressor) worth the money or better with a newer setup that would run on the 220 and operate in the 22-25 amp range??.

[68protouring454]

if you can bury the wire i would go for it, what about putting a sub panel in garage and running some #2 or something so you can get 50-60 amps out there, would not be much more money than #6 and you would have the capability to run ights, a 220 welder,etc are you handy at wiring??
jake