Checking Out Used Air Compressor

[btuser]

I'm looking for a big air compressor for my house, something that will run an impact wrench and maybe some other stuff. Rationale is I can blow out my own sprinkler system if I've got a big tank and some time to kill, so why not pay myself the $75/yr? I think my system is a good candidate because all the zones boxes are above the heads, so the natural slope will do most of the work.

I want something that will push a lot of air when I need it, but I don't have to worry about putting people out of work if its not running so a lightly used one will do fine. I'm going to look at a unit (5hp 80 gallon) that was used at a machine shop. This could either mean its beat to heck, or was taken care of very well (mechanic's cars, carpenter's houses ect) so I want to know what to look for. It was custom built 12 years ago but the shop has been out of business for a few years and now its time to clean the garage.

What do I look for?

 

[benjamin]

I'd look for single phase, a uniform coat of dust (nothing pressure washed, or excessive oil leakage), belts in good shape or uniformly worn, proper oil level, and no bearing slop.

If it's running you could time how long it takes to build pressure, but I wouldn't know how long that should be.

 

[thinkxingu]

Rap the tank to hear any potential dead spots, fill it and give it a few minutes to see if it's holding air, listen when it's filling for superfluous engine noise, etc. Just a note: not sure what you're paying for the unit, but you can pick up an Ingersoll-Rand 60-gallon for around $600 at TSC. My father bought an IR 25 years ago, and I bought one a couple years ago. Sweet.

S

 

[btuser]

Nice tip on the tank. I don't think I'm going to be able to get it running. Its one of those things where it "has to go" divorce, ect. I was hoping to get it for about $300, but I also don't want to rip the guy off. I'd prefer to buy new but at $600 my payback period would be 10 years instead of 4. This is really one of those things I can barely justify so I have to go cheap. Time will tell if I get lucky, or end up learning how to fix it.

I've noticed a very wide range when it comes to comparing 5hp compressors. Is there a way of getting a ballpark (other than filling and timing) what its rated for? I'm guessing the nameplate on the motor would be a clue.

 

[SolarAndWood]

cfm @ 90 PSI seems like the common measure. For example, my pancake is 2.8, the little wheelbarrow is 4.4 and the 60 gallon with the 5hp is 9.4. The pancake can't keep up with a roofing or framing gun if you are moving. The little wheelbarrow can handle one gun but can't keep up with two. I haven't run into anything the 60 gallon can't keep up with but I am just a happy homeowner.

Definitely check the tank...the 5 hp on my splitter came from a rotted compressor.

 

[Singed Eyebrows]

I'm looking for a big air compressor for my house, something that will run an impact wrench and maybe some other stuff. Rationale is I can blow out my own sprinkler system if I've got a big tank and some time to kill, so why not pay myself the $75/yr? I think my system is a good candidate because all the zones boxes are above the heads, so the natural slope will do most of the work.

I want something that will push a lot of air when I need it, but I don't have to worry about putting people out of work if its not running so a lightly used one will do fine. I'm going to look at a unit (5hp 80 gallon) that was used at a machine shop. This could either mean its beat to heck, or was taken care of very well (mechanic's cars, carpenter's houses ect) so I want to know what to look for. It was custom built 12 years ago but the shop has been out of business for a few years and now its time to clean the garage.

What do I look for?

What brand of pump is on the unit? I'm a little late on this thread so you might have bought one already. You probably will pay about the same for a used industrial quality unit as a used China compressor. Ideally you want a 4 pole(1725) motor, decent quality. You want a V belt drive unit. The biggest problem with an industrial unit is that most will have a 3 phase motor. If you can get something like a single phase Quincy 3 to 5 hp that is in decent shape, thats the last compressor you will ever need. I cleaned valves on 35 year old ones in factories that ran 2 shifts a day & they were in great shape. Old Champion gas station compressors are still around, these can be really hammered up though Good luck, check Craigslist, auctions are a real good souce too, Randy

 

[btuser]

Raising the thread from the dead. My little compressor died (so glad, oi-free and loud as could be) so now the hunt is back on. Craftsman has a 60 gallon on sale right now. Oil lubed but the reviews are so terrible I'm not going to take the chance (how many of these are people not breaking them in right). Might go look at a IR T30 this weekend, 80 gallon with a 7.5 Baldor motor. Enough air for the neighborhood but I'm scared with how much work its going to be to get it into place, and then maybe move it.

Anybody else build a shed just for their compressor? Maybe a good spot for the generator too. Ahhh, the projects.

 

[Singed Eyebrows]

Raising the thread from the dead. My little compressor died (so glad, oi-free and loud as could be) so now the hunt is back on. Craftsman has a 60 gallon on sale right now. Oil lubed but the reviews are so terrible I'm not going to take the chance (how many of these are people not breaking them in right). Might go look at a IR T30 this weekend, 80 gallon with a 7.5 Baldor motor. Enough air for the neighborhood but I'm scared with how much work its going to be to get it into place, and then maybe move it.

Anybody else build a shed just for their compressor? Maybe a good spot for the generator too. Ahhh, the projects.

I would be leary of the Craftsman, even the older ones were marginal. Is the IR T30 painted blue? If so this is a very good quality machine. If there is any knocking in it you will need to overhaul it or risk scattering the insides(crank is supported on one end only). If it's painted a beige color it's quality is less although still a decent machine. Randy

 

[maverick06]

I have the older model of this one: http://www.harborfreight.com/2-hp-8-gallon-125-psi-portable-air-compressor-67501.html

With the 20% off coupon its a good deal. I have been using it for the past 5 years with good service. The check valve was sticky for a few months (if you left pressure in the tank, it wouldnt want to start up if the compressor cooled down). The check valve unstuck shortly there after and its been great. not super quiet (compressors arent) It does everything I need to. Re-shingled my shed roof, used the air nailer. It provides a limited duty cycle for the impact wrench... maybe 30%. Also after it has been running for many min, the head gets quite hot. I was initially worried about this, but 5 years of service (lots) and its running great. It owes me nothing and gives me smiles!

 

[smokinj]

Thats a good size compressor. If she runs and blows and not alot of money great deal. No more than your going to run it!