Air Compressor Advice

I'm looking into getting a compressor for my garage. Saved up 700 and found one at Lowes. It's an 80gal., 4.5 running hp, 14 cfm @90 psi., single stage for 599.00. I'm going to use your typical air tools along with a sandblaster. I don't sandblast anything large so it's typically just 1-5 minutes at a time.

What do you guys think? I know it's a purchase you'll have forever but I also don't want to spend a fortune. I'm thinking this will do everything I'll ever need.

14cfm@90 psi is way over kill for the typical home requirements. Your sand blaster is likely to be your largest consumer of air, and it would take a beefy, manly blaster to require 14CFM and with 80 gallons on tap you can easily use something in the 20-30 CFM range for short bursts.

IOW - you can't go wrong. The price is right, and by the looks of them, Kobalt makes a sound piece of equipment. Take after me (and many other wise compressor operators) and install a ball valve at the bottom for easy draining after each use. DO NOT leave air in the tank overnight, for days, for weeks on end etc. I'll take pictures of my simple arrangement of parts I picked up from lowes. Follow the manual for break-in and oil change intervals and you should get decades of operation. Periodically check that the pressure relief valve releases air as it should. And never use extension cords with your compressor - it WILL shorten it's life.

Having a compressed air system is a beautiful thing. Goodluck!

-MechanicMatt

You stated,
" DO NOT leave air in the tank overnight, for days, for weeks on end etc."
Why not?
What is your reasoning on that procedure?
I have the pet-cock on the bottom of the tank and dont get much water out of it at all. open it once every three mo. or so.
I do recomend a in-line water seperator. Now that you would drain daily. but not to drain the air out of the tank every day.

Well, if this compressor is going to be used in a shop that does a lot of automotive repair, this is a decent size, especially, if you are going to be sandblasting.

I have a 13 gallon/4hp and it runs constantly, if I'm sand blasting. I only do small stuff with my sand blaster. Bigger stuff, I just take to the shop.
So, for this, an 80 gallon isn't a bad investment. If you got a good deal on it, then you did good.

You stated,
" DO NOT leave air in the tank overnight, for days, for weeks on end etc."
Why not?
What is your reasoning on that procedure?
I have the pet-cock on the bottom of the tank and dont get much water out of it at all. open it once every three mo. or so.
I do recomend a in-line water seperator. Now that you would drain daily. but not to drain the air out of the tank every day.

It's recommened to drain every night if used daily or after each us if not being used daily. This is to remove moisture to keep the inside of tank from rusting.

GAS,

I don't have much to say about your having little/no water in your tank after 3 months.

My 30 gallon snap-on unit (overpriced - don't buy their compressors) generates quite a bit of condenation inside the tank every day. Given: I use a lot of air keeping the fleet in repair, and the cycling may have something to do with this, as well as working near the beach. Nonetheless, the moisture causes rust, and the pressure aggrivates corrosion.

You're the first source I've ever heard criticise the draining of an air compressor. At Toyota, we drained the receiver everyday. I do the same with mine because I don't want to die next to my air compressor, much less have to replace the receiver, because I ignored the instruction manual.

I too run an in-line air/water/oil seperator (5 micron i believe, craftsman unit), but if you've done any research you're aware that these are more or less useless, as I'm sure you've noticed as I have, that I still get water through my tools! The truth is, if you want a real water removing device, you need to buy a 1200 dollar regfrigerator/dryer as these are the ONLY way to realistically remove water from the line.

At least we all seem to agree that you choice of compressor is sufficient, eh dwen? =)

-MechanicMatt

http://i77.photobucket.com/albums/j64/isc20/002.jpg

Real simple. Much easier than reaching under and twisting the petcock every time you drain, just kick it and forget it. Thread pitch is NPT of course, so you wont have to worry about thread pitch. Use teflon tape, and that's all there is to it. Definitely one of my favorite compressor mods.

-MechanicMatt

If I understand impacts correctly, when they say 625 ft. lbs of torque, they're refering to it in reverse right? The gun I'm looking at is...
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=2623

It says torque range 40-400lbs. Which I'm guessing is in forward and reverse is 625. I'm thinking this gun will either twist em off or snap em off.

By the way Matt, I like your set up on your compressor and think I'll copy it. I'll take pics when I get that big mamma home!

I'd say it will snap them off....

I'm not sure how they are rating that gun but the torque for a high strength 7/8 bolt is only about 450.... One of the bridges I was working on the inspector made a mistake and wanted the 7/8 bolts torqued to 625ft lbs and we were snapping them off before we got them there. Better be careful with that bad boy LOL

It has been my experience that impact wrenches are rated a bit high. My reason for thinking this is that my impact wrench here (http://www.sears.com/shc/s/p_10153_12605_00919274000P?filter=Automotive+Air+T ool+Type%7CImpact+wrenches%5EBrand%7CIngersoll-Rand&vName=Tools&cName=Compressors+%26+Air+Tools&sName=Automotive+Air+Tools) is rated for 600ftlbs. But there have been times, trying to install/remove heavily damaged lug nuts, when it just wouldn't go anywhere. Sit and hammer a lot, but not budge. Then with a 24" breaker bar, use less then my full weight to get it off. I weigh about 140 lbs, x 2 feet = a maximum of 280lbft of torque I can deliver without jumping. So, clearly there's some margin here.

Nontheless looks like a fine unit to start with and it will not disappoint you I'm sure. It's recommended to oil once a working day with some good air tool oil which I completely agree with. I however seldom oil my air tools, and my air ratchet is evidence of that - I can stop it from moving with my bare hands and it is supposed to be rated at 45lbsft. Oh well. Live and learn I guess. I also have my line pressure set at 135 psi which mind you, is 45psi higher than is recommended for most air tools.

As far as twisting/break stuff apart, it's perfectly okay to blast nuts and bolts off at full power - it wont hurt anything as it will almost never require the full force of the wrench to take off say, lug nuts, cam and crank bolts, hub nuts, strut to knucle bolts - that is: they will start to move before the wrench delivers thread-damaging torque. And if you do thrash something, odds are the threads were on their way out anyhow. I strongly suggest investing in a nice tap and die set =)

What I did with my impact to get an idea of where it is at the various 4 power levels, is impact a lug nut on at power 1, then take my torque wrench and record the last value that did not move the nut. So I know that my impact wrench at power level 1 tightens the average lug nut to ~60ftlbs. I seldom use anything higher than power level 1 or 2.

Just throwin some ideas out there.

-MechanicMatt

PS - Impact wrenches almost always have a higher reverse torque than forward torque.