As far as capacity is concerned, I agree that people should go by the CFM
rating @ some PSI, NOT the HP rating of the motor. That said, when buying a
compressor you also should consider the electric usage. Large compressors
use a lot of juice. In our area rates have reached 8.3 cents per kilowatt
and rising. A friend of mine, who lives-off the-grid in Oregon tells me
that the high speed compressors use a lot less current. He measures
everything because he gets all his power from solar panels.
A technique I've used is to gang two smaller compressors together during
the time I need to sand blast or run the DA sander. I borrowed the second
one from a friend. If they have on-board pressure regulators, you have to
take the output ahead of the regulators. I've found that, among other
problems, the regulators restrict the output to less than the capacity of
the compressor.
At 12:38 PM 12/10/01 -0600, Kyle Chilcoat wrote:
>A two stage compressor will run much longer without heating up as bad and
>the compressor can catch up much faster than the single stage compressors.
>If you run an air sander than the smaller compressors will have a hard time
>keeping up with your work. You should also look at the NEMA rating on the
>motor to see if its capable of running continuously at high torque, such as
>when the compressor is already charged up to 90+psi. It takes a lot
>morepower to start a single stage compressor when the tank is already
>partially charged.
>
> I personally have a large industrial compressor that delivers
> about 29cfm @
>190psi but i have a lift and other such things that i use. Its a little
>overkill but i got it cheap enough that i couldn't pass it up.
>
>Hope that helps you
>
>Kyle C.
>55-1
>-----Original Message-----
>From: owner-oletrucks@autox.team.net
>[mailto:owner-oletrucks@autox.team.net]On Behalf Of A.B.
>Sent: Monday, December 10, 2001 11:28 AM
>To: Old Chevy Pickup
>Cc: old truck mailing list
>Subject: Re: [oletrucks] compressed air
>
>
>While we are talking about air compressors, I've been doing some research
>because I'm thinking of upgrading my compressor.
> >From previous threads, it seems like most people on this list seem to
>think 2 stage is the way to go because you can get high PSI (usually 175)
>and CFM (around 15 for the compressors I've been looking at). I'm just not
>really sure why I need 175 PSI? For about 1/3 to 1/2 the price of a 2
>stage compressor, I can get a single stage compressor that will deliver up
>to 16 CFM at 90 PSI. It seem slike most air tools only require 90 PSI, so
>why do I need 175? I'm not trying to be cheap, just educated. Thanks.
>-alfie
>
>
>On Mon, 10 Dec 2001, Old Chevy Pickup wrote:
>
> > Doug,
> >
> > Here are two.
> > http://www.sharpe1.com/dr-pipe.htm
> > http://www.tptools.com/StaticText/piping_diagram.pdf
> >
> > Dan Jacobsen - PA
> >
> > '49 3100 327/powerglide
> > '55.1 3100 rodstoration 350/350 MII
> > '48 4400 Front sheet metal on a '87 chassis (still need a cab)
> > '35 Dodge Business Coupe - All original
> > '35 Dodge Business Coupe - Complete parts car - Future streetrod project
> >
> >
> >
> > >From: "Doug Pewterbaugh" <dpewter@msn.com>
> > >Reply-To: "Doug Pewterbaugh" <dpewter@msn.com>
> > >To: "Bruce K" <bekett@uslink.net>, <oletrucks@autox.team.net>
> > >Subject: Re: [oletrucks] compressed air
> > >Date: Mon, 10 Dec 2001 10:12:51 -0600
> > >
> > >Somebody recently posted a link to a compressed air equipment
>manufacturers
> > >website that included a very detailed hypothetical air layout for a home
> > >sized shop. Sorry, I can't find the URL. Anyone else?
> > >
> > >Regards,
> > >Doug Pewterbaugh
> > >dpewter@msn.com
> > >Denton, TX
> > >49 3104 216 5-window
> > >
> > >----- Original Message -----
> > >From: "Bruce K" <bekett@uslink.net>
> > >To: <oletrucks@autox.team.net>
> > >Sent: Saturday, December 08, 2001 10:08 PM
> > >Subject: Re: [oletrucks] compressed air
> > >
> > >
> > > > An air line can never be too big or too strong <g>
> > > >
> > > > I would go with the steel pipe. Your plan sounds good, but don't
> > > > forget to set the pipe up so any water trapped in it can be drained.
> > > > Forget PVC, it gets weak if it is too hot or cold.
> > > >
> > > > I don't think you really need galvenized pipe, black should do just
> > > > fine for inside work. Remember to seal the threads.
> > > >
> > > > I would use a short piece of hose to the compressor for the final
> > > > link to isolate vibration and I would use a valve at the compressor
> > > > to shut the system off if something goes bad.
> > > >
> > > > Secure the bibs well, they take a lot of force from the air hose
> > > > attached to them. At each bib, I would put a T with a dead downbound
> > > > leg about 6" long to catch any rust or dust that makes its way down
> > > > the pipe.
> > > >
> > > > I don't know how large your compressor is, but I would include a
> > > > 1" valve and plug for a future port close to the compressor if you
> > > > want to sandblast or tie in a portable compressor some day.
> > > >
> > > > I would set the main pipe up to slope towards drain points. It
>doesn't
> > > > take much, 1/8 inch per foot is fine.
> > > >
> > > > Don't forget to put in a few unions here and there in case you ever
> > > > have to take the assembly apart for some reason.
> > > >
> > > > Finally, compressors are noisey and they should be fed clean air.
> > > > Think about putting the compressor in a separate shed outside the
> > > > garage.
> > > >
> > > > Have fun. Renting a good Rigid pipe cutting and threading tool for
> > > > the day when you put it together will make things go quicker. Sure
> > > > beats having the hardware store cut and thread a bunch of pipe
>sections
> > > > or buying lots of nipp1es. (don't know about this board, but some
> > > > screen for words like that!)
> > > >
> > > > If it freezes in your area, be sure to blow out any moisture in the
> > > > system in the fall.
> > > >
> > > > Bruce Kettunen
> > > > 57 3200
> > > > MN
> > > >
> > > >
> > > >
> > > > At Saturday, 8 December 2001, you wrote:
> > > >
> > > > >Hey all,
> > > > > I am looking to add compressed air in my shop. The question
> > > > is what kind
> > > > >of pipe. Galvanized steel, black iron, or PVC. PVC is sure cheaper
> > > > but I'm
> > > > >told perhaps unsafe. I am only looking to handle 125psi with 1"
> > > > pipe to the
> > > > >general bench area then 1/2" to the drop points with curly plastic
>from
> > > > >there. Any advice on what is best? Thanks..........tom 50---3600
> > > > >oletrucks is devoted to Chevy and GM trucks built between 1941 and
>1959
> > > > >
> > > >
> > > >
> > > >
> > > >
> > > > ===================================================================
> > > > EASY and FREE access to your email anywhere: http://kralweb.com/mail
> > > > ===================================================================
> > > > oletrucks is devoted to Chevy and GM trucks built between 1941 and
>1959
> > >oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
> >
> >
> > _________________________________________________________________
> > oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
>oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
>oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
Tom Allen
Seattle, WA
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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