[TheForge] Re: air compressors revisited.

[Mike Spencer]

Terry wrote:

> in an  effort to get a better handle on air compressor usage i would to
> ask members of theforge e-mail list several questions.
>
> 0. what is the h.p. or kilowatt rating for the air compressor you
> current use as your primary pressurized air source?

My scenario is probably more in the way of an entertaining anecdote
than useful business advice.  Wash dog first, etc.

I got along without compressed air for decades.  I borrowed or rented
a compressor a couple of times, borrowed space in an air-equipped shop
once and rented a glass bead cabinet for a day once.

When I found an Atlas Copco all-cast iron, 400 psi, 3-stage compressor
for $250 a few years ago, I went for it, as is, where is.  Replaced
the 10HP 3PH motor with a 2HP until I found a 5HP for another $200
that I hooked up with scavenged 8ga wire.  Got a free 80 gal.  Halon
tank rated for 600PSI from another blacksmith.  A basket of (new)
switches, relays, valves, hydraulic hose, air hose, fittings, couple
of tools etc. plus some machine work and I'm close to $1000, about
what I'd have to pay (or a bit less) for an aluminum 2-stage
made-in-China burns-out-next-Tuesday compressor of similar CFM.

The compressor itself is so old that Atlas Copco doesn't admit that
they ever made it. I found a guy on the net who works for them and has
database access.  There's no record of it.  So parts could be a
problem if it ever breaks but it's a good bet that my light usage at
150 PSI isn't going to break it.

This, for what it's worth, has been my approach for most shop gear.
Years ago, I bought a cut-off band saw and a 1/2" drill press new
because I needed them.  But even then, (and not counting all the
antique blacksmithing hand tools) the average age a a tool in my shop
is probably something like 50 or 60 years.  (My 1925 B&D 1/2" drill
and end-grinder both run fine. B&D even had a replacement brush holder
for the grinder in the early 70s.)

> 2. do you consider your current air compressor to be adequate for your
> needs and requirements?

Yeah, but even a little die grinder can have the compressor stop & go,
stop & go.  If I could find a hand-held air chisel/hammer -- the size
that's sort of like an automatic weapon -- to forge with, I'll bet
the compressor wouldn't be able to keep up with continuous use.

> ...i am attempting to keep this simple so that a clear and clean
> decision may be made...

Oop.  Well, I *said* it was more of an entertaining anecdote.

Bunch of guys, lots of air tools: 5HP isn't going to be enough.
Couple of guys, an air wrench or two, maybe a small chisel and a
blow-things-out nozzle, 5HP is probably fine. (I don't have a clue
about paint-sprayer air consumption but a even a small, Mickey Mouse
sandblaster will keep a 5HP compressor going non-stop.)



- Mike

-- 
Michael Spencer                  Nova Scotia, Canada       .~. 
                                                           /V\ 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^