HF compressor purchase

Dunno what you mean by "larger". Nailers aren't big users, but air sanders are real hogs. It takes a huge compressor to run, say, and orbital sander for any decent duty cycle.

I'll second that. You need to match the cfm of the compressor to the tool. Have him look at tools he's interested in before he buys a compressor. I did it the other way around and ended up not happy with one and bought a 5 HP Ingersol Rand.

Lane

Beware that the CFM given on the package for the tool may be for an absurdly low duty cycle.

Richard J Kinch wrote in news:Xns952DC451DAA8Dsomeconundrum@216.196.97.131:

As a rule of thumb, I figure 2 to 2.25 x rated cfm for full duty on many tools, some will run close to rated, say 1.5. Similarly, figure about 0.8 to 0.85 for air compressors vs label rating.

I own an IR 2135 Ti.. (Its a nice 1/2" impact gun)

The Avg Air consumption is listed at 5 CFM. At load, that goes up to

24 CFM.

Now, how they come up with 5 CFM as an average I don't know. Maybe after the fastener is initially broken and the bolt is being backed out it requires much less air. The initial hits that loosen the bolt are probably going to exhaust a compressor tank in short time.

Realistically the CFM requirement is probably a lot closer to 24 than

5 CFM.

__________________ Note: To reply, replace the word 'spam' embedded in return address with 'mail'. N37.3 W122.0

thanks I remember the thread about airtool ratings. I guess the rule in this case will be bigger is better. Thanks Karl

The "average" is just whatever the manufacturer thinks the typical tool buyer wants to believe. Reality doesn't seem to have much to do with it.

There is no general rule for how much manufacturers overrate air compressor delivery, or underrate air tool consumption. The only way to know is to analyze the claims (e.g., compare compressor electrical ratings to typical efficiency) and/or to actually measure the performance. The (literally) puffed-up numbers are a fantasy that has no decoder.

Air sanders are about the only tool that I have given up on, they are the biggest air hog short of a blow gun. You need at least 10 - 15 CFM to use one for anything like useful work. Things like impact wrenches may call out a big cfm, but you typically use them for 30 seconds or so per application. You use an air sander to maybe 30 minutes straight, often...

Brian

application.

I don't understand the obsession with air tools... I sell power tools and although there is some real crap out there, we sell some very nice electric tools that should not fatigue the user as a cheap one would.

I use pneumatic disc and die grinders at work. Yesterday, I used them for six hours straight (duty cycle in excess of 70%). I generally find them under powered and I certainly wouldn't want to put my own compressor through that kind of abuse. The disc grinder is worth about $900 Cnd while the die grinder is worth about $400. About the only good feature is their size. They are significantly lighter and smaller than their electric counterparts. Mind you, if they were more powerful, perhaps I wouldn't have to use them for so long...

Just my $0.02 worth.

Regards,

Robin

See the other comments about air hogs!

I have a little Proter Cable pancake style tank compressor that goes with me for framing nailer, roofing nailer, and the rest of the staplers and finishing nailers. None of those uses enough air to run the little compressor very often.

Switch to the sander, tank lasts about 2 m> My brother asked me to check. He's considering buying one of the larger HF

I agree with you, Robin, it seems kind of pointless to run a 5 hp motor to power a drill when I can run my 18V cordless instead...

the only air tools I use regularly is the blow gun (hard to imagine an electric blow gun), tire inflator (ditto), impact wrench, butterfly wrench, die grinder (good electric die grinders are pretty expensive, reasonable air die grinders are cheap as chips) and air chisel.

||My brother asked me to check. He's considering buying one of the larger HF ||compressors first to air nail the new siding on his house but afterwards to ||run an air sander (for wood) and anything else he comes up with. Figure ||amateur woodworking and home renovation ( his house only). Also, how are the ||HF airnailers for the same use?

I got a small one a few years ago for attaching baseboards. Works fine, but I have never used a brand name nailer. This is more like a brad driver. Texas Parts Guy

If I'm going to plug it in anyway, I'll run my $300 Metabo heavy-duty electric hand drill. Drilling through cast steel die sections with a pneumatic drill sucks.

We sell electric blowers at work. Not as powerful as a blow gun, but reasonably effective for cleaning off a work area (chips and dust).

Electrics are dime a dozen (12V).

The largest impact we sell at work is rated at 722ft/lbs.

That's true about the die grinder, but I find mine pretty weak. Not exactly a roughing tool though.

I don't think I've ever seen an electric air chisel. Not really our type of product though.

Regards,

Robin

||I agree with you, Robin, it seems kind of pointless to run a 5 hp motor to ||power a drill when I can run my 18V cordless instead...

I have a good cordless, a 1/2 Craftsman corded drill, and a couple air drills. When I have some tough drilling to do, the air drills get the nod. Last month I needed to drill through a beam axle in 4 places (x2 thicknesses) of steel to install a rear swaybar. The electric drills would have given up halfway through that job. The air drills made it relatively easy. Same with rollcage tubing. Air chisel is occasionally indispensible, and does not have a common electric counterpart. The impacts and other air wrenches speed up part removal, particularly when it's a tight spot to swing a wrench. I usually use hand tools for reassembly, except for a long thread runup.

Texas Parts Guy

"Brian" wrote in news:6DPLc.36607$ snipped-for-privacy@nnrp1.uunet.ca:

The largest air hog I've ever used is an air file. Try one of those for a couple of minutes...that's about all you will get on a 80 gal tank, with a (rated) 14cfm compressor.

"Robin S." wrote in news:4OQLc.29304$ snipped-for-privacy@news20.bellglobal.com:

Robin, What size air supply you have to it, and at what pressure? I used to have a problem with my cut-off grinder, in that it lacked power. But switching from one of those (supposedly) 1/4" coiled air hose, to a straight coupled 3/8" hose, cured that problem. At 90 PSI, I have to really bind it to get it to stall. I also suggest 'Blaster' air tool oil, really good stuff.

"Brian" wrote in news:mbRLc.36642$ snipped-for-privacy@nnrp1.uunet.ca:

I use mostly air tools at work, and the single largest reason is that air is much more readily available on the floor than is electricity (well, at

120V anyway.) Every machine has an air hook-up, the 120V electrical outlets are few and far between, even if you were just using battery power, you have to charge it somewhere.

What size? I have no idea. Something like "huge". It wouldn't surprise me to see twenty pneumatic grinders running simultaniously at any point throughout the day. We also run two robotic welding cells (roughly eight robots in each) that use pneumatic clamping. Then there's the presses and CNC machines...

I don't think it's a supply issue - I think the grinders are just weak. They sacrifice quality for power. It's not unsual to use a disc grinder for several hours of actual use per day. Some guys have more expensive, more powerful grinders that have less vibration but they're probably worth in excess of $1500 each.

We use the straight 3/8" rubber hose.

It takes a fair amount to stall mine, but nothing like an electric tool where a safety clutch will preven the tool from breaking your arm...

I don't get much of a choice in that department. Whatever the tool crib has is what I use. :-)

Regards,

Robin