specs for an adequate air compressor

[mrtoyota]

So an 8 gallon, 4.3/3.5 SCFM at 40/90 PSI compressor is on sale, it's a good price. I want one to opporate basic air tools (impact wrench, paint gun, etc.) and was wondering if other people using small compressors have found them to be adequate. I'm not running a big shop here, just maintaining and modifying the jeep and doing household chores. Just wondering if anyone out there who knows anything about compressors could give me a bit of advice. Should this little guy do the trick? After reading the reviews, I think this one will do, I just might have to take er easy and give it time to refill a little more often, I really can't beat the price, but just wanted to get a few opinions from people who have a little more experience with compressors than I do. Here's the link for those of you who care:

http://www.canadiantire.ca/AST/brow...P/Mastercraft%2B8G%2BCompressor.jsp?locale=en

 

[RCP Phx]

Well, its an oilless type, so buy ear plugs with it!

 

[mrtoyota]

It's oiled, unless "Lubrication - Oil" under specs means oiless

 

[iwannadie]

4.3/3.5 SCFM sounds pretty low to me. Mine does 15/10 and I want more ha.

Check what tools you plan to run they all list the required CFM ratings and then add a little to that cause they seem to list on the low end.

 

[old_man]

I've been using air compressors for over 45 years. Not trying to be an ass, but that thing is too small to do much more than run a ratchet or air up a tire. For instance, a DA random orbital sander will run about 60 seconds before you run out. An impact wrench might pull one wheel before having to recharge. I tend to say that at a minumum you need a 20 gallon tank and at least 2 hp. and not oilless.

 

[POSJ]

I've got a 30 Gal 4hp, and I hate it...I want at least double the capacity. It gets old taking off wheels and then trying to do other work while your tank recharges.

 

[old_man]

My answer was for the minimum. I run an 80 gallon with a 6.5hp compressor.

 

[POSJ]

No I know old_man I was just putting in my opinion. For my use I wouldn't use less than the 30gal 4hp.

 

[mrtoyota]

Thanks guys, I appreciate the input. I'd rather know these things now and not have to buy another one in the future. I had noticed that the specs were border-line for a lot of the tools that I wanted to run, just wasn't sure if I could get away with border-line and a small tank, now I know I can't!

 

[stumpXJ]

Its all about CFM for a compressor. The one you mentioned is extremely low. I would say at LEAST you want 8-10cfm @ 90PSi.

Ive got 9cfm at 90psi w/ a 28gallon tank, and I always over pull from it with air tools (die grinders, DA's, etc). If you ever plan to run a sand/bead blast cabinet, you had better be pushing or 15-20 cfm @90 psi to keep up with it.

This is one tool that you cant really buy one thats too big.

 

[OttawaXJ]

I have that one. Its pretty decent actually but as others said, its not an awesome quality but it does everything I've wanted it to do so far.

I dont need a 30 gallon compressor to cut half my XJ off or to run a shop with 3 KOH rigs in it or something.

All I need it for is to air up tires, use the impact gun, air ratchet and a few other things. Its handy and at 140$ I think it was a decent buy for my uses.

 

[old_man]

If that is all you want, then it will do. I started that way and have always regretted not starting bigger.

 

[stumpXJ]

If that is all you want, then it will do. I started that way and have always regretted not starting bigger.

X2, its kinda like buying a welder. You should get the biggest you can right off the bat, or you will want more later on, especially if you are or are becoming a wrench/gear head.

 

[XJJD]

IR Garage mate, I love mine so far only compressor I haven't killed.

 

[NW-ZJ-SCOTT]

that compressor will run an impact.. at about 1/4 capacity on its fullest charge.

the compressor i was using had 8cfm at 90psi and even at 100psi it only ran my 600ft/lb impact at half capacity..

 

[iwannadie]

that compressor will run an impact.. at about 1/4 capacity on its fullest charge.

the compressor i was using had 8cfm at 90psi and even at 100psi it only ran my 600ft/lb impact at half capacity..

How do you rate what power your impact is putting out? I mean how can you accurately say that your impact gun was only at half capacity?

 

[NW-ZJ-SCOTT]

How do you rate what power your impact is putting out? I mean how can you accurately say that your impact gun was only at half capacity?

What i mean by that is, if its rated at 500ft/tq and it cant even break a second lug nut that's torqued to 95ft/lbs, you do to the math..

 

[XJJD]

that compressor will run an impact.. at about 1/4 capacity on its fullest charge.

the compressor i was using had 8cfm at 90psi and even at 100psi it only ran my 600ft/lb impact at half capacity..

Sounds like you had an issue with your regulator or the impact gun, even a cheap harbor freight compressor and a cheap impact gun will do lug nuts all day long. I'm currently running the IR Garage mate with a cheap impact gun and it will break your wrist.

 

[XJJD]

oh, but I did forget if you had the old single cyl garage mate those did suck you need the new v twin with the intercooler pipe. (not kidding).

http://www.google.com/products/catalog?hl=en&q=garage+mate&cid=5621009416780534084&os=reviews

 

[iwannadie]

What i mean by that is, if its rated at 500ft/tq and it cant even break a second lug nut that's torqued to 95ft/lbs, you do to the math..

I'm no expert but it sounds like it was just not getting air. The first lug nut you don't mention having problems with so it was running the gun at full power. Just the way your saying it runs the impact gun at 1/4 power makes no sense to me. If it's getting 90psi then it's at full power, just for how long depends on the tank. What was the regulator showing when you hit the second lug nut, was the compressor immediately kicking on when you pulled the trigger or what?

My tank is pretty small(35 gal I think) but I can remove and replace(gun Set to half power) all 4 wheels without the tank recovering. My compressor kicks on when it drops below 125psi or something close to that when it's set to 130psi and 90psi on the regulator. Many times I'll crank up the compressor then once it's full just turn it off and do what I need with the impact gun it's nice ha. My IR thunder gun doesn't suck the tank dry very quick at all.