Need a new air compressor... What to look for???

[adamnitti]

My air compressor bit the dust the other day. How much do I need to spend to get something reliable that I can use for my air tools, etc... ? Also, do I want to get one that's labeled as 'oil free?' Any recommendations?

[thabaer]

Post some PSI+CFM specs for your tools and tools you would like to use, that will help in making recommendations. There will be a camp who says only oil-filled and some people have reported painting, air-chisel, DA sanders for years on a teflon unit with no failure.

I garonntee dissenting views will materialize here

BTW: good review of the new album in Modern Drummer a few months ago!

[adamnitti]

charlie, thanks for the reply. geez... i'm embarassed to say i don't know the specs you speak of. :-) i'm still building the tool shed... right now just depending on impact driver and air ratchet for starters. i just want something that isn't going to break for a LONG, long time.

that's cool you saw that review! thanks again-

[Chuck Moreland]

Not an expert but I just got a shop size compressor. It's a 220V floor mount with a 60 gallon tank that specs at 11 CFM @ 90 PSI.

I am happy with it. That's a lot of compressor for one guy but anything less I think would be a problem for some continuous tools like my angle grinder.

Here it is prior to buiding the enclosure:



A smaller one is fine for bursty things like an impact wrench and air ratchet.

I am told the oil-less ones are noisier. Even mine was so loud that I built an enclosure around it largely to control the sound. It helped a great deal too.

[jess p]

As a general rule, you need about 5hp to operate any kind
of air tools.










66 912 with 350 sbc
77 911S
66 912 2.2 with nitrous

[VincentVega]

Spend a little more than you think you want to and get one that will always do what you need. I've used a small 30gal 5hp sears for years and it's noisy and will not run a sander, chisel or grinder for more than a few seconds.

I suggest going with a 2 stage 220v unit that is oil lubed. As Chuck said piston type is the only way to go. Home Depot sells a husky that's pretty nice for ~$800. Sears also sells a model in their "Professional" line for ~$850 I am going to pick up sooner than later. They seem to have it for $800 2-3 times a yr. For it's specs you usually have to spend over $1k. I also suggest installing PCV pipe around the garage to give you several air hookups. It might sound like overkill, but when you have 50ft of hose all over the place you will be thankfull.

Happy Hunting!

[911pcars]

I just saw a nifty compact vertical elec. compressor at OSH (owned by Sears), I think about 30 gallon tank. It was 120 VAC, dual stage and on wheels which isn't too common. Most dual-stage compressors tend to be 220VAC. Advantage of dual-stage are the higher pressures these can supply (120-150 psi) - just the ticket to make the impact guns work. I forget the asking price; maybe around $400 or so.

Sherwood Lee
http://members.rennlist.org/911pcars

[Zeke]

All I can say is see if you can hear it run before you buy it. All of today's crap is noisy to the max. What ever happened to the old gas station compressors that you could carry on a converstion while they were running?

[code7rpd]

I have used both the oil free and those that take oil. My prior compressor was a Crasftsman 5hp, 25 gallon tank that was oil free and it ran on 110V. It was stil working after 7 years and was great. I decided to sell it before it broke and I bought a Husky 110V 5hp, 30 gallon tank at Home Depot for a $350. It has the same power and CFM specs but seems to have more power than the craftsman. It is the type that takes oil. I have seen marketing ads for both compressor's and even though they have the same specs, the oil free types have smaller pistons/cylinders. I don't know why but my Husky has a much bigger motor than the Crafstman. The other good thing is that the Husky has a 3 yr warranty.

[code7rpd]

Also, If you check out www.chpower.com you will see Campbell Hausfield compressors that have been refurbished by the factory at a good price with a warranty.

[MotoSook]

I have Craftman 5HP 80 gallon that I picked up for 249. Not bad..for the home mechanic. Now Chuck's is killer, but he does a lot more work in his garage than I do I bet.

Edit....I lost my head for a second there...I have a 6HP/30 Gallon unit. Works GREAT! for $249

[stormcrow]

Look at your cfm requirements if you don't want to have a large storage tank. All compressors can put out 120 psi or more, but the cfm is the driving force. Minimum requirements would be 3 to 5 cfm to operate most tools.

Reserve capacity is another biggie. The larger the tank, the more reserve capacity you have without the compressor contiually cycling on and off. But, when the tank is low on air, it has to replenish it. The more cfm the unit has, the faster it will fill the tank to keep up with demand.

Steve

"A Porsche does more then just go fast in a straight line"

[dad911]

I also suggest installing PCV pipe around the garage to give you several air hookups. It might sound like overkill, but when you have 50ft of hose all over the place you will be thankfull.

Standard plumbing PVC can be brittle & explode with cold/age. Use iron pipe, tip tools has layout ideas here that prevents moisture problems in lines. http://www.tptools.com/statictext/piping_diagram_2003.pdf

[Porschedude]

I guess it depends where you live dad911,

In my area we never freeze. I have a system setup in my garage with QD outlets using 3/4" PVC pipe. It has been installed for 10 years without a hint of a problem. One thing I don't do is leave the system charged all the time. I have a valve that isolates the branch portion of the system from the compressor. I also have a loop type water trap built from the same PVC pipe with two Sears Water Traps in series. Down stream of that I have a Sharp Drier before the QD that I use for painting. (1 compressor, three driers, 7 QD outlets, and I never get any water out of my spray gun or any of my air tools).

The compressor I have is a Sears Craftsman 5hp piston type that I bought to prep a car for paint. That was 20 years ago and the thing runs pretty well to this day.

The reason I bought this model, was because I knew of a guy (childhood friend) that prep'ed and painted cars in his parent’s front yard. His compressor ran 10 hours a day for 7 or years and looked beat to death, but still ran. These compressors are made for Sears by DeVilbiss, which is a very big outfit and produces professional equipment.

I have run DA (dual action) Sanders, drill motors, impact drivers, palm sanders, die grinders, nail guns, 6” hand grinder, 2X rivet guns, and long board sanders on this system and the only problem with capacity is using the long board sander for any length of time. The DA sander is sometimes marginal with a lot of work.

I don’t think one could go wrong with a Sears or a Campbell Hausfeld of proper size.

Keith

[jmohn]

IMHO: minimum 3 HP 60 Gal. tank or 5 HP 30 Gal. tank (how much space do you have? bigger is better), be sure you have enough electrical capacity (most larger, more useful, units will need 220 volts), if you go with a smaller tank be sure the pump will supply 4-5 CFM of "free air" (this is the CFM at the pressure you will be using, e.g. mine supplies 7 CFM @ 90 PSI). A loop air system is nice and can be done in PVC although copper tubing is more common here (1/2" ID is generally large enough), just be sure to use PVC (it's not all the same) rated for higher pressure (usually sched. 40 or better), use proper fittings/connections and properly hang it with slight pitch back to a drain (generally at a water trap near the compressor) to prevent "ponding" in the line. Drain/clean/replace the water traps and filters and service the pump and tank periodically and any of the brands mentioned by others will be fine.

Jerry M
'78 SC

[Porschedude]

jmohn,

Most assuredly schedule 40 or better yet, schedule 80.

I wouldn't even us the class 125 in my yard sprinkler piping.

Spec

http://www.csupomona.edu/~rkumar/lis231/231tables/pvcclasst.html

http://www.harvel.com/PVCpipe4080spec.html

[bfrenz]

Check this one out. Not associated with them but I have also been looking.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=11768&item=2512120044

[MBAtarga]

PVC pipe is NOT recommended for the use of compressed gases.

http://www.osha-slc.gov/dts/hib/hib_data/hib19880520.html

Some excerpts from above link:
The main problem with using PVC pipe and fittings for compressed gas is not that it spontaneously explodes but that PVC is a brittle material that can be broken or shattered with external force unless properly protected. Compressed gasses can be best described as being analogous to a coiled spring. When a PVC pipe or fitting fails when under stress from compressed gas it literally explodes like a bomb, sending shards of plastic flying several feet in all directions. Liquids, on the other hand, being compressed by only 1/10th of 1% contain very little stored energy. When pressurized systems with liquids fail, the energy is dissipated very quickly, thereby creating a much lower potential for hazard.

Only one type of plastic pipe has been approved for use with compressed air. That pipe, Acrylonitrile-Butadiene-Styrene (ABS), is marked on the pipe as approved for compressed air supply.

[jmohn]

I stand corrected, Mark. I thought the newer CPVC products could be used, but a quick look at the limited resources I have here at home show me you're correct.

Jerry M
'78 SC

[adamnitti]

wow. great info, guys. thanks.

what do you all think of this one? it's a 2 stage, and it's in my budget. not sure if it has enough hp, though. thanks again-

http://www.sears.com/sr/product/details/productdetails.jsp?BV_SessionID=@@@@1526774623.104 7751235@@@@&BV_EngineID=ccdhadchkjfghhhcehgcemgdffmdflh.0&vertical=TOOL&prod_id=00916778000&fromAuto=YES&bidsite=CRAFT

here's another one with more hp and cfm, but i don't know if it's 2 stage or not:

http://www.sears.com/sr/product/details/productdetails.jsp?BV_SessionID=@@@@1526774623.104 7751235@@@@&BV_EngineID=ccdhadchkjfghhhcehgcemgdffmdflh.0&vertical=TOOL&prod_id=00919541000&fromAuto=YES&bidsite=CRAFT