[Shop-talk] single vs. dual stage compressors

[Paul Parkanzky]

I thought that the point of 2-stage was higher PSI, but that doesn't seem to
be the case here.  In other words, I bought a single stage IR with a max
pressure of 125 PSI, and the 2-stage was rated at 175 PSI.  175 PSI
affectively increases the capacity of your tank.

Also, what is 19.1 cfm@ 125 PSI at 90 PSI?  I bet it's a ton.

If you're thinking about using sanders, blasting, painting, etc. I'd look
for a lot of CFM and a compressor rated for continuous duty.

-Paul


On 11/20/08, Mark Andy <mark at sccaprepared.com> wrote:
>
> Howdy,
>
> Whats the deal with single vs. dual stage compressors?
>
> I've long been thinking that I'd want to get a decent 60 or 80 gallon two
> stage compressor when I upgrade next.  But I was reading the recent TP Tools
> thanksgiving sale flyer and they had some listings for High output single
> stage compressors.
>
> One in particular was $650 and has a working pressure of 95-125 psi, with
> 16.5 cfm @ 90 psi (Eagle brand three cylinder 5 hp running, 23A at 230VAC,
> 7hp peak, 60 gallon).  No spec on pump rpm.
>
> That's as compared to $1300 for a Champion 5hp two stage, @19.1 cfm @125
> psi, 22A @230vac.  The pump rpm on this one is 805rpm
>
> I realize that 19.1 cfm @ 125psi is more air that 16.5 cfm @ 90 psi, but
> would I ever care about that?  I'm going to be a single user using normal
> air tools like cut offs & body sanders, plus a blast cabinet, perhaps
> painting a car, etc.
>
> Currently I have a Craftsman direct drive single stage that says it does 7
> scfm @ 90psi... That thing won't keep up with a cutoff very long.
>
> Half price is pretty attractive if it'll do what I need it to do...
>
> Mark