Fran Schwartz on tue 24 aug 99
Hi Clayarters,
There has been much discussion about the pros and cons of various spray
guns,and I, too,am ready to buy one. But what about a compressor . I'm
starting from scratch and don't know how to determine which one to get. Any
ideas about size, producers,prices and where to find one? Any ideas you have
on or off the list would be greatly appreciated. (The more I learn,the more
questions I have)
Thanks,Fran
Bill Campbell on wed 25 aug 99
Sizing a compressor to your spray equipment should be really easy. Check the
literature that comes with the spray gun it will tell you how many CFM [cubic
feet per minute] is necessary to operate your gun. Since glazes tend to be
more viscous than what is ordinarily put thru a gun I would err on the large
side to insure that you have all of the power that you will need. Once you
have ait in your shop you will find many more uses for it .
Bill
WHew536674@cs.com on wed 25 aug 99
Fran,
A good source for compressors is Grainger. They sell them in all sizes and
prices. They range in price from $60 to $500. Most of them put out more
pounds of pressure than you'll need for spray glazing. I set my compressor
at 35-40 pounds of pressure, and I'm happy with that. Another factor is how
long a time you want it to run. With the larger ones the pressure in the
tank stays up for as long as you want. Some of the smaller ones you may have
to wait till the pressure builds up again, after using for a while, and that
can be annoying. If you plan on using it a lot, for an indefinite amount of
time, I'd go for the portable tank, easy to wheel around, and that is a 3
horse power motor, with 125 psi, and cost about $125. Make sure to bring
your spray gun with you so they can set it up with the right attachments.
Joyce A
In S. TX, where the hurricane, tornados, rain and winds are finally gone
Martin Howard on wed 25 aug 99
Bought a little thing, which was really for artists rather than potters.
It was too small for real pottery work. Then I went to my supplier, who
is always helpful. She had some old stock, but was not restocking,
because it has become too complicated.
But there was one solid looking job jumping out at me. So for less the
thirty pounds I bought it.
So, what about a compressor. Too expensive. But my helpful supplier said
" when in college, I did my thesis using a foot pump".
Right, so now I have a new double barrelled foot pump, the right
connections and the new spray gun. Going to fix it all together sometime
today. Will report back later.
We potters are used to using feet at the same time as hands, so why not
use the feet to power the spray gun? Save on electricity. Now if someone
could invent a real bellows type footpump for fitting to a Leach wheel,
that would be very useful.
Of course, we then need a spray cabinet to fit onto the wheel as well,
which could easily be done.
Martin Howard
Webbs Cottage Pottery and Press
Woolpits Road, Great Saling
BRAINTREE
Essex CM7 5DZ
01371 850 423
araneajo@gn.apc.org
Vince Pitelka on thu 26 aug 99
I posted about this a few years ago, but it is worth repeating. If you are
shopping for a compressor big enough to spray glazes, be sure to get one
with a cast iron barrel (compressor cylinder). I was in a Lowe's Home
Improvement Center the other day, and was appalled to see that among their
entire line of compressors, not a single one had a cast iron barrel. All of
the major manufacturers (Quincy, Ingersol-Rand, Speedaire, etc.) make
compressors with cast-iron barrels, including some which are fairly
reasonably priced. Campbell-Hausfield makes a line of very reasonably
priced cast iron compressors called the "Cast Iron Line" which are
excellent. I have a Campbell Hausfield two-horsepower cast iron compressor
with a ten-gallon tank which I purchased from Monkey-Wards 25 years ago. I
have used the heck out of it for everything imagineable, and it works today
exactly as it did the day I bought it.
Cast iron compressors seem to always be belt driven. I think this is
because cast iron cannot dissipate the heat fast enough to be used in a
direct drive situation, where the compressor is rotating at the same speed
as the motor. This means that with a cast iron compressor they must use a
larger compressor unit, usually a two-cylinder, operating at a slower speed,
in order to get the same CFM output. So, for much less money, they can
manufacture a direct-drive compressor with an aluminum barrel which puts out
the same CFM, but will beat itself to death in short order. And yet they
try to market direct drive aluminum compressors as if they are somehow
superior!! I asked the guy at Lowe's about it, and he tried to convince me
that these units are really better than the cast iron ones. He had been
brainwashed.
This kind of cut-rate design is used frequently. In the old days (now I'm
starting to sound like a genuine old fart) a five-horse-power single-phase
motor was about a foot in diameter and weighed 200 lbs. Now, they have
somehow come up with 5 hp. single phase motors which are hardly larger than
a 1/2 hp. washing-machine motor, but they manage to extract five hp. from
them. But you know, those big old ones kept going indefinitely, and the new
ones do not.
A contemporary 2-hp. gas engine weighs about 30 lbs. I own a beautiful
turn-of-the-century DeLaval Dairy Supply Company 2 hp. single-cylinder gas
engine with two big flywheels and at least 25 pounds of brass trim. The
whole engine weighs about 750 lbs. but it will do the work of two horses.
You can buy a Corvette with a 375 hp. engine. I want to see it do the work
of 375 horses.
I did not mean for this to evolve into a rant about the degeneration of
quality and honesty in machinery design. If you are shopping for a
compressor, bring a magnet, look for a compressor with at least a 2 hp.
motor and a belt-drive between the motor and the compressor unit, and check
the compressor cylinder (the part with the cooling fins, like a motorcycle
cylinder) with the magnet. If it is cast iron, the magnet will stick, if it
is aluminum, it won't. Don't let those yahoos sell you a direct drive
compressor with an aluminum barrel.
Good luck -
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Martin Howard on thu 26 aug 99
It works, so why buy expensive compressors?
Just amend the connector to your footpump, lengthen the hose a little so
that the working height for the spray gun is OK, and you can spray away
in time with your footmovements. Use the left foot for the kick wheel,
to rotate the ware, the right for the car tyre footpump, one hand for
the spray gun and you've still got a hand free for holding the stencil
in place :-)
I have been an organist for much of my life, so used to using the pedals
and for much of the time even operating bellows with my feet.
Martin Howard
Webbs Cottage Pottery and Press
Woolpits Road, Great Saling
BRAINTREE
Essex CM7 5DZ
01371 850 423
araneajo@gn.apc.org
Brian Crocker on thu 26 aug 99
I think you will find, most spray guns that are capable of handling Glaze, need
an air supply of 12 to 15 cubic feet per minute at 40 pounds per square inch
pressure from the regulator. As long as you have a compressor with a standard
size receiver [tank] you should need no larger than a 15cfm output in fact
many people have a 12cfm compressor and it copes quite well. The viscosity
of the material being sprayed generaly relates to the spray gun being used and
not to the compressor as long as it has the abovementioned cfm available.
I hope that helps,
Kind regards,
Brian C..
At 04:56 PM2:10: 25/08/99 EDT, you wrote:
>----------------------------Original message----------------------------
>Sizing a compressor to your spray equipment should be really easy. Check the
>literature that comes with the spray gun it will tell you how many CFM [cubic
>feet per minute] is necessary to operate your gun. Since glazes tend to be
>more viscous than what is ordinarily put thru a gun I would err on the large
>side to insure that you have all of the power that you will need. Once you
>have ait in your shop you will find many more uses for it .
>Bill
>
>
Brian Comley-Crocker.
4 Erica Street,
Tea Tree Gully 5091,
South Australia. [e.mail] crocker@dove.net.au
Phone/Fax: 08 8264 4136
The Crock maker.
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