Christopher Tidy wrote:
Grant Erwin wrote:

Christopher Tidy wrote:

I've been looking at a few second air compressors. I've always
understood the volume flow rate quoted in CFM to refer to the flow
rate at atmospheric pressure, not the flow rate at the compressor's
maximum working pressure. Can someone confirm this for me?



Oh, god not again. We beat this to death and then some awhile ago,
much much flames with mucho heat but very little light. I read
thousands of lines of postings and didn't understand what the gurus
were saying. Typical specs are given at 40psi and again at 90psi, but
the way I read it none of this matters
somehow. It doesn't really matter about the theory, a decent 5hp
2-stage compressor can keep up with a die grinder, that's all I really
care about.


Well actually my thoughts were more pragmatic too. I was looking at this
second hand compressor:

http://www.mythic-beasts.com/~cdt22/compressor.jpg
http://www.mythic-beasts.com/~cdt22/compressor2.jpg

I know it's old, but I love projects. The whole thing is 28" long and
has a motor rated at 0.75 hp at 1440 rpm. There are two small air
receivers underneath you can't see. Basically I was wondering what kind
of tools I could run off it. A few things I'm interested in are paint
spraying, a die grinder, Cengar saw (a.k.a. shark saw, as used by the
fire service) and inflating tyres. At a rough guess I reckon this
machine has a flow rate of 6-8 CFM at atmospheric pressure. Any thoughts?

Best wishes,

Chris


I'll say that some compressed air is a lot better than none. When I was
a kid I had a little corn-popper compressor with about a 4 gallon tank.
I could knock 5 wheel nuts off if I loosened them all first, but if I
took three all the way off there wan't pressure enough to break the last
ones loose.. but it would air up a tire just as good as a big one..

John