Klyf Brown on sat 9 feb 02
I did not sleep at a certain Inn last night, but I am a contractor and
own several spray rigs of each type.
The guns I saw on Harbor Freights sight are advertised as HVLP, I
just don't see how. One required 50 to 70 psi. That is not low
pressure. My regular pot spray guns (Binks, about $200) only need
30 to 40 psi. A true HVLP gun can not be powered by a
compressor. They don't put out enough vouume. HVLP guns are
expensive because they require a turbine, not a compressor. The
actual guns cost $100 to $200. If you think a compressor is
annoying, try listning to a turbin, like a jet plane. A compressor will
shut off on occasion, the turbin needs to be on all the time you are
spraying. A compressor can be located in another room or outside if
you use a larger hose. A turbin needs to be close to the gun. A benifit
of the HVLP is that the turbin produces hot air, the sprayed material
dries almost on contact. The spray pattern is adjustable from a small
round dot to a long narrow band thus reducing overspray, also the
low pressure produces less waste. If you buy a good gun, you can
also replace certain parts (needles, tips) that are larger and will allow
spraying some high solids, thick coarse materials.
If you see a gun advertised that has a regular size hose, it is not
HVLP. They use a large (one inch or larger) air delivery line, usually
clear.
I bought a cheap chinese gun once. At 40psi the bottom inverted and
pooched out as a dome, it looked like it was ready to blow. Scared
the hell out of me. I hook everything up with quick couplers and was
able to unhook it quickly. Took a sledge hammer to it after emptying
the cup so no one else would be tempted to use it.
A tip for compressor users; they make air scrubbers that are not
expensive. They remove the oil and water from compressed air. Just
don't mount them close to the compressor, they need to be farther
away from the unit to let the air cool off enough that the vapour will
condense and be trapped by the consolidator.
If you buy quality tools you will need to buy them only once.
Poorly made tools can be dangerous.
Klyf Brown in New Mexico where it is too cold to throw neeked.
george koller on sun 10 feb 02
So from all this I am thinking that this item will fall somewhere
between: high tech miracle product of the year at an unbelievable
price - and - another piece of "chinese tool crappala" that Klyf can
take up on a roof and take a sledge hammer to. (If seems interesting
enough I might offer to ship it off to Vince or somebody to evaluate
further.)
It's on order. That's a fairly open range of possibilities.
I can't wait. (For the record: I don't expect it to be a "contractor"
or "industrial duty" kind of tool at all. But that should not preclude
being a ok to great tool for occasional use in a studio. )
======
Thanks Klyf,
Just a note: The gun I ordered to evaluate is a COMPLETE system
including the turbine or equivalent. That is what is so interesting to
me. It is being sold at $69.99. It will be worth that to hear what it
sounds like now. It operates at 4PSI so it is the TRUE HVLP. What
most of us are calling HVLP these days and paying from $40 to $200
or more for is not a true HVLP but some sort of "pseudo hvlp" that still
uses a compressor. Somebody in marketing cheated and got away with
it. You are absolutely right, and I think this is a source of a lot of
confusion.
-------------------------------------------
For those interested enough to see for yourself here is a direct link
to a picture and the description of the subject HVLP spray system:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?function=Search
then you have to enter this item# in the search:
44677-2VGA
warning: NOBODY on this list has had a chance to evaluate yet. just
conjecturing. I have one on order and will be looking at late next week
at earliest opportunity. i promise to give it a fair go. maybe i can run it
past bruceG or bonnieS on my way back to wisconsin to see what they
think.
--------------------------------------------
So you have given me another idea:
Warming the air going into, or heating it in a chamber along the exit side
of the "turbine". fascinating idea!?! This might be another step
toward an improved studio spray gun for glazes. In our tile work we
have a per tile target of about 40 grams for the (4" X 4") tiles - this
is a lot of material and a lot of water to dry out. On humid days this
can take 12 hours or so. So this might be a trick to cut that time down,
maybe even remove the need for a lot of time on the drying racks.
On the other hand the "bonding" to the bisque may not be as good.
We'll see.
Also as I remember using a true HVLP a couple of times years ago
it seemed easier to gage the thickness of the material going on.
Maybe it was because it was nott varying between wet and dry so
much after it was laid down?
Sincerely,
george koller
sturgeon bay, wi - door county
PS
Going off-list for at least a week. Leaving for Michigan. Meeting
with my "Alfred connection" guy to go over software and our motion
control equipment. Excited. New software additions are allowing
specification of the saturation levels we lay down on the base glaze.
We will be controlling the "spits per second". The newest nozzle we
are testing spits at about 0.0000005 liters (that's five nano-liters right?).
You can only just see it before fired but a real "dot" after fired for
most salts. We think this will also be great for building up signs.
The software I developed two years ago is finally "busting through -
getting connected" to our world and can now start show us what it
can do.
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