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29/12/2003 5:39 AM

Where is true information on air compressors?

I am looking for an air compressor for my workshop.
The first task will be to drive nailers to build a shed and then spray paint
the shed. After this the compressor will primarily be used to run nailers a
vacuum clamp and press system (4.2 cfm advertised requirements) the
occasional air tool (sanders, nailers, impact wrenches) and some finishing.
I don't have a lot of 220 volt access or abundant space. The current
benchmark I am considering is a Campbell_Hausfeld direct drive oil less 6.5
HP 28Gal compressor at Lowe's $270. The problem I am having is finding real
information. I am under the impression that the advertised capacities are
like a politicians promises. and I can find almost nothing on what the duty
cycles of various compressors are. The CH web site is sad. I have done
google news group searches. Does anybody have a good source of experience
or information?
Thanks in advance
Marty


This topic has 6 replies

JJ

JGS

in reply to [email protected] on 29/12/2003 5:39 AM

29/12/2003 6:14 AM

The paint sprayer and the sander will determine the size of compressor you
need. Some of them need a lot of air. Cheers, JG

Dan Parrell wrote:

> to best meet your requirements,try obtaining the information on the tools
> that will be used ie the CFM's or proper operatiing pressures.The compressor
> you speak of should have no problem doing the job,mine is no where as big as
> that one but has no problem running the air nailer.
> <[email protected]> wrote in message
> news:[email protected]...
> > I am looking for an air compressor for my workshop.
> > The first task will be to drive nailers to build a shed and then spray
> paint
> > the shed. After this the compressor will primarily be used to run nailers
> a
> > vacuum clamp and press system (4.2 cfm advertised requirements) the
> > occasional air tool (sanders, nailers, impact wrenches) and some
> finishing.
> > I don't have a lot of 220 volt access or abundant space. The current
> > benchmark I am considering is a Campbell_Hausfeld direct drive oil less
> 6.5
> > HP 28Gal compressor at Lowe's $270. The problem I am having is finding
> real
> > information. I am under the impression that the advertised capacities are
> > like a politicians promises. and I can find almost nothing on what the
> duty
> > cycles of various compressors are. The CH web site is sad. I have done
> > google news group searches. Does anybody have a good source of experience
> > or information?
> > Thanks in advance
> > Marty

mm

momo99

in reply to [email protected] on 29/12/2003 5:39 AM

29/12/2003 5:00 PM

Marty,

Here is the scoop on air compressors:
1 true HP will make 4-5cfm @ 90psig for an oil-lubed compressor. The
ratings you will see on the el-cheapo units are peak HP or locked
rotor HP and have nothing to do with true running HP. Motor Mfg's do
not make 6.5 HP motors! These are probably 2-3 HP.
Large tanks can provide extra air for peak demands, but cannot make up
for large continuous flows.
Also, taking oil out of a compressor makes it noisier, reduces the
output cfm/HP, and cuts the life expectancy of the unit.
Duty cycle for an oilless is 50% at best, vs 80-100% for an oil-lubed
compressor.
That said, you do have to remove the oil from the air stream with good
filters.
Most paint sprayers need >10cfm, so you are looking at ~3HP of real
compressor.
Check www.air.irco.com for SS3L3 shop compressor. makes 11.3cfm @
90psig for 3HP(7.9 peak) 15amps 230V. 5year warranty and 100% duty
cycle. Plus this unit is worth rebuildingwhen the time comes.

Let me know if you have any more questions.

Best Regards,

Momo



On Mon, 29 Dec 2003 05:39:07 GMT, [email protected] wrote:

>I am looking for an air compressor for my workshop.
>The first task will be to drive nailers to build a shed and then spray paint
>the shed. After this the compressor will primarily be used to run nailers a
>vacuum clamp and press system (4.2 cfm advertised requirements) the
>occasional air tool (sanders, nailers, impact wrenches) and some finishing.
>I don't have a lot of 220 volt access or abundant space. The current
>benchmark I am considering is a Campbell_Hausfeld direct drive oil less 6.5
>HP 28Gal compressor at Lowe's $270. The problem I am having is finding real
>information. I am under the impression that the advertised capacities are
>like a politicians promises. and I can find almost nothing on what the duty
>cycles of various compressors are. The CH web site is sad. I have done
>google news group searches. Does anybody have a good source of experience
>or information?
>Thanks in advance
>Marty

DP

"Dan Parrell"

in reply to [email protected] on 29/12/2003 5:39 AM

29/12/2003 6:43 AM

to best meet your requirements,try obtaining the information on the tools
that will be used ie the CFM's or proper operatiing pressures.The compressor
you speak of should have no problem doing the job,mine is no where as big as
that one but has no problem running the air nailer.
<[email protected]> wrote in message
news:[email protected]...
> I am looking for an air compressor for my workshop.
> The first task will be to drive nailers to build a shed and then spray
paint
> the shed. After this the compressor will primarily be used to run nailers
a
> vacuum clamp and press system (4.2 cfm advertised requirements) the
> occasional air tool (sanders, nailers, impact wrenches) and some
finishing.
> I don't have a lot of 220 volt access or abundant space. The current
> benchmark I am considering is a Campbell_Hausfeld direct drive oil less
6.5
> HP 28Gal compressor at Lowe's $270. The problem I am having is finding
real
> information. I am under the impression that the advertised capacities are
> like a politicians promises. and I can find almost nothing on what the
duty
> cycles of various compressors are. The CH web site is sad. I have done
> google news group searches. Does anybody have a good source of experience
> or information?
> Thanks in advance
> Marty

AD

Andy Dingley

in reply to [email protected] on 29/12/2003 5:39 AM

29/12/2003 3:32 PM

On Mon, 29 Dec 2003 05:39:07 GMT, [email protected] wrote:

>After this the compressor will primarily be used to run nailers a
>vacuum clamp and press system (4.2 cfm advertised requirements)

This is a vacuum system that uses a compressor and an air ejector to
produce a vacuum ?

IMHO, don't do it. They're hungry for air and awfully inefficient. In
practice this means sharing your workshop with a fairly large
compressor and having it running near-continuously. It works, but it's
an unpleasant way to work.

_Much_ better is to find a vacuum pump. You can buy one (a _very_
rough vacuum is adequate) or you can eBay a S/H lab vacuum pump (you
can get them for about $75 locally). Because this is more efficient
(it's not using an ejector) it's a lot smaller and thus quieter, for a
given vacuum capacity.

Make sure you get something that's happy pumping down a closed vacuum
chamber all day. Fridge compressors can be rigged to work as vacuum
pumps, but they start to arc-over if they're left running closed off.


As for nailers, then almost any compressor can run them. Doesn't need
much air. Random orbital sanders are one of my favourite air tools
(for woodworking) and they're a bit thirstier though - depends on the
quality too.
--
Klein bottle for rent. Apply within.

WL

"Wilson Lamb"

in reply to [email protected] on 29/12/2003 5:39 AM

29/12/2003 7:55 PM

You'll hate the noise of the direct drive!
I'd get the 5-6 HP one for about $400. It should last a lifetime and you'll
never challenge it, except for sandblasting, which must be intermittent.
Mine is about 10 yrs now, no problems.
If you are short of space, cet the upright, but the horizontal, on wheels,
is great to loan out or take to outside jobs.
If you really don't want to run 240V, then get the biggest 120V machine they
have.
Wilson
<[email protected]> wrote in message
news:[email protected]...
> I am looking for an air compressor for my workshop.
> The first task will be to drive nailers to build a shed and then spray
paint
> the shed. After this the compressor will primarily be used to run nailers
a
> vacuum clamp and press system (4.2 cfm advertised requirements) the
> occasional air tool (sanders, nailers, impact wrenches) and some
finishing.
> I don't have a lot of 220 volt access or abundant space. The current
> benchmark I am considering is a Campbell_Hausfeld direct drive oil less
6.5
> HP 28Gal compressor at Lowe's $270. The problem I am having is finding
real
> information. I am under the impression that the advertised capacities are
> like a politicians promises. and I can find almost nothing on what the
duty
> cycles of various compressors are. The CH web site is sad. I have done
> google news group searches. Does anybody have a good source of experience
> or information?
> Thanks in advance
> Marty

GG

Greg G.

in reply to [email protected] on 29/12/2003 5:39 AM

29/12/2003 7:07 AM

[email protected] said:

>I am looking for an air compressor for my workshop.

The CFM and pressure specs are generally fairly accurate, the HP
ratings are grossly overstated. The compressor cycle time is
dependant on the air use of the tool and the size of the tank.
Ultimate maximum continuous flow is determined by the compressor
itself.


Greg G.


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