Air Compressor Requirements

I am contemplating buying a new compressor for my garage. Tools I plan
to use are air ratchets, inpact gun, small die grinders, cutoff tool
and maybe a sprayer. My question is the tool that will probably put
the most demand on the compressor is the cutoff tool. Using about
25cfm @load. So if I go with a portable compressor 120 volt, 2hp,
30gal. tank, putting out 5.7cfm @ 90psi., I figure I can run this
cutoff tool for only 30 plus seconds before the tank drops below
90psi. Anyone have any first hand experience using a cutoff tool for
cutting say a 1/2 inch bolt or 1inch angle iron? How long would it
take to cut off a 1/2 inch bolt using a carbide wheel? If it takes
much longer than 30 seconds, then I am into cutting and waiting,
cutting and waiting. If this is the case then I will opt for a 220
volt 60gal. tank 15cfm @90psi. But going this route and I lose my
portability. Any constructive thoughts or coments most appreciated.

B.T. wrote:
> I am contemplating buying a new compressor for my garage. Tools I plan
> to use are air ratchets, inpact gun, small die grinders, cutoff tool
> and maybe a sprayer. My question is the tool that will probably put
> the most demand on the compressor is the cutoff tool. Using about
> 25cfm @load. So if I go with a portable compressor 120 volt, 2hp,
> 30gal. tank, putting out 5.7cfm @ 90psi., I figure I can run this
> cutoff tool for only 30 plus seconds before the tank drops below
> 90psi. Anyone have any first hand experience using a cutoff tool for
> cutting say a 1/2 inch bolt or 1inch angle iron? How long would it
> take to cut off a 1/2 inch bolt using a carbide wheel? If it takes
> much longer than 30 seconds, then I am into cutting and waiting,
> cutting and waiting. If this is the case then I will opt for a 220
> volt 60gal. tank 15cfm @90psi. But going this route and I lose my
> portability. Any constructive thoughts or coments most appreciated.
>

My air compressor is "portable" in that it has wheels, but it's heavy.
It's just a Home Depot Coleman two stager 120V with a 27 gallon tank.
(It can be rewired to run on 240 and that's what I did in my old garage.)
It's rated at 5.7cfm@90 psi as well.
For home use, it rocks. I have a race car, and during the summer it
gets pretty heavy usage at times, yet I don't normally have to wait for it.

My tank regulator fills up to about 120 psi, so you can use the
equipment for a bit before the tank pressure drops to 100psi and the
pump kicks in, and my compressor usually seems to be able to handle a
load like that and still stay around 80psi, so when you stop to examine
your cut it pumps back up to above 90 and you're good to keep on going.

About the only air tool I have that kills it is the orbital sander - not
sure how much air it uses, but it's a lot.

Ray

On Apr 22, 1:47 pm, ray > wrote:
> B.T. wrote:
> > I am contemplating buying a new compressor for my garage. Tools I plan
> > to use are air ratchets, inpact gun, small die grinders, cutoff tool
> > and maybe a sprayer. My question is the tool that will probably put
> > the most demand on the compressor is the cutoff tool. Using about
> > 25cfm @load. So if I go with a portable compressor 120 volt, 2hp,
> > 30gal. tank, putting out 5.7cfm @ 90psi., I figure I can run this
> > cutoff tool for only 30 plus seconds before the tank drops below
> > 90psi. Anyone have any first hand experience using a cutoff tool for
> > cutting say a 1/2 inch bolt or 1inch angle iron? How long would it
> > take to cut off a 1/2 inch bolt using a carbide wheel? If it takes
> > much longer than 30 seconds, then I am into cutting and waiting,
> > cutting and waiting. If this is the case then I will opt for a 220
> > volt 60gal. tank 15cfm @90psi. But going this route and I lose my
> > portability. Any constructive thoughts or coments most appreciated.
>
> My air compressor is "portable" in that it has wheels, but it's heavy.
> It's just a Home Depot Coleman two stager 120V with a 27 gallon tank.
> (It can be rewired to run on 240 and that's what I did in my old garage.)
> It's rated at 5.7cfm@90 psi as well.
> For home use, it rocks. I have a race car, and during the summer it
> gets pretty heavy usage at times, yet I don't normally have to wait for it.
>
> My tank regulator fills up to about 120 psi, so you can use the
> equipment for a bit before the tank pressure drops to 100psi and the
> pump kicks in, and my compressor usually seems to be able to handle a
> load like that and still stay around 80psi, so when you stop to examine
> your cut it pumps back up to above 90 and you're good to keep on going.
>
> About the only air tool I have that kills it is the orbital sander - not
> sure how much air it uses, but it's a lot.
>
> Ray- Hide quoted text -
>
> - Show quoted text -

Thanks for the reply. I think what I may do is rent a compressor that
has close to the same specs as the portable I'm looking at, along with
a cutoff tool and carbide wheel, and try some cuts on some 1 inch
angle iron and some 1/2 inch bolts. I'll see how long it takes me to
cut through these items before the pump drops off to the point where I
need to wait for it to recover. If i can cut through these items in 30
secs. or less I'll have no problem meeting most all of my needs.
Thanks again for the response. B. Taylor

B.T. wrote:
> On Apr 22, 1:47 pm, ray > wrote:
>
>>B.T. wrote:
>>
>>>I am contemplating buying a new compressor for my garage. Tools I plan
>>>to use are air ratchets, inpact gun, small die grinders, cutoff tool
>>>and maybe a sprayer. My question is the tool that will probably put
>>>the most demand on the compressor is the cutoff tool. Using about
>>>25cfm @load. So if I go with a portable compressor 120 volt, 2hp,
>>>30gal. tank, putting out 5.7cfm @ 90psi., I figure I can run this
>>>cutoff tool for only 30 plus seconds before the tank drops below
>>>90psi. Anyone have any first hand experience using a cutoff tool for
>>>cutting say a 1/2 inch bolt or 1inch angle iron? How long would it
>>>take to cut off a 1/2 inch bolt using a carbide wheel? If it takes
>>>much longer than 30 seconds, then I am into cutting and waiting,
>>>cutting and waiting. If this is the case then I will opt for a 220
>>>volt 60gal. tank 15cfm @90psi. But going this route and I lose my
>>>portability. Any constructive thoughts or coments most appreciated.
>>
>>My air compressor is "portable" in that it has wheels, but it's heavy.
>>It's just a Home Depot Coleman two stager 120V with a 27 gallon tank.
>>(It can be rewired to run on 240 and that's what I did in my old garage.)
>>It's rated at 5.7cfm@90 psi as well.
>>For home use, it rocks. I have a race car, and during the summer it
>>gets pretty heavy usage at times, yet I don't normally have to wait for it.
>>
>>My tank regulator fills up to about 120 psi, so you can use the
>>equipment for a bit before the tank pressure drops to 100psi and the
>>pump kicks in, and my compressor usually seems to be able to handle a
>>load like that and still stay around 80psi, so when you stop to examine
>>your cut it pumps back up to above 90 and you're good to keep on going.
>>
>>About the only air tool I have that kills it is the orbital sander - not
>>sure how much air it uses, but it's a lot.
>>
>>Ray- Hide quoted text -
>>
>>- Show quoted text -
>
>
> Thanks for the reply. I think what I may do is rent a compressor that
> has close to the same specs as the portable I'm looking at, along with
> a cutoff tool and carbide wheel, and try some cuts on some 1 inch
> angle iron and some 1/2 inch bolts. I'll see how long it takes me to
> cut through these items before the pump drops off to the point where I
> need to wait for it to recover. If i can cut through these items in 30
> secs. or less I'll have no problem meeting most all of my needs.
> Thanks again for the response. B. Taylor
>

My personal recommendation would be to buy the largest one that you can
afford and will fit in the space you have for one (and that you have
wiring to support.) Trust me when I say that once you *have* one, you
will find more uses for it than you currently anticipate.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

B.T. wrote:
> I am contemplating buying a new compressor for my garage. Tools I plan
> to use are air ratchets, inpact gun, small die grinders, cutoff tool
> and maybe a sprayer. My question is the tool that will probably put
> the most demand on the compressor is the cutoff tool. Using about
> 25cfm @load. So if I go with a portable compressor 120 volt, 2hp,
> 30gal. tank, putting out 5.7cfm @ 90psi., I figure I can run this
> cutoff tool for only 30 plus seconds before the tank drops below
> 90psi. Anyone have any first hand experience using a cutoff tool for
> cutting say a 1/2 inch bolt or 1inch angle iron? How long would it
> take to cut off a 1/2 inch bolt using a carbide wheel? If it takes
> much longer than 30 seconds, then I am into cutting and waiting,
> cutting and waiting. If this is the case then I will opt for a 220
> volt 60gal. tank 15cfm @90psi. But going this route and I lose my
> portability. Any constructive thoughts or coments most appreciated.
>

Go with the largest CFM output and motor size you can afford for a shop
unit. You will regret going smaller. Oh and you will be doing a LOT of
cutting/waiting with the smaller unit.

--
Steve W.
Near Cooperstown, New York

"Nate Nagel" > wrote in message
...
>
> My personal recommendation would be to buy the largest one that you can
> afford and will fit in the space you have for one (and that you have
> wiring to support.) Trust me when I say that once you *have* one, you
> will find more uses for it than you currently anticipate.
>
> nate

Wise words, even if you have to go in hock a little and do some
rewiring/rearranging, go for a two-stage with at least a 60 gallon tank.

On Apr 22, 7:09 pm, "Steve W." > wrote:
> B.T. wrote:
> > I am contemplating buying a new compressor for my garage. Tools I plan
> > to use are air ratchets, inpact gun, small die grinders, cutoff tool
> > and maybe a sprayer. My question is the tool that will probably put
> > the most demand on the compressor is the cutoff tool. Using about
> > 25cfm @load. So if I go with a portable compressor 120 volt, 2hp,
> > 30gal. tank, putting out 5.7cfm @ 90psi., I figure I can run this
> > cutoff tool for only 30 plus seconds before the tank drops below
> > 90psi. Anyone have any first hand experience using a cutoff tool for
> > cutting say a 1/2 inch bolt or 1inch angle iron? How long would it
> > take to cut off a 1/2 inch bolt using a carbide wheel? If it takes
> > much longer than 30 seconds, then I am into cutting and waiting,
> > cutting and waiting. If this is the case then I will opt for a 220
> > volt 60gal. tank 15cfm @90psi. But going this route and I lose my
> > portability. Any constructive thoughts or coments most appreciated.
>
> Go with the largest CFM output and motor size you can afford for a shop
> unit. You will regret going smaller. Oh and you will be doing a LOT of
> cutting/waiting with the smaller unit.
>
> --
> Steve W.
> Near Cooperstown, New York- Hide quoted text -
>
> - Show quoted text -

Thanks to all who responded. I do appreciate the help. B. Taylor

On 23 Apr 2007 11:12:17 -0700, "B.T." > wrote:

>Thanks to all who responded. I do appreciate the help. B. Taylor

If I'm not tooo late....

I have a Coleman 5HP on a 27gal tank. I'm in the garage most every
weekend and can count on one hand how many times I have needed more
air than it can keep up with. It is about 8 years old and still works
as good as the day I bought it but.....

I hate it. I hate it more than any tool I have ever bought.

If you can at all avoid it don't get a direct drive compressor. Get
one of the ones with a separate motor and compressor section. The
direct drive units are so noisy I can't stand to be in the garage with
it. I can't use the compressor when anyone in my house or the
neighbors house is asleep. I find myself quite often not using it
when I would like to just because I don't want to listen to the damn
thing.

My .02
Steve B.