Vince Pitelka on sun 15 jan 06
Maurice Weitman said:
> Gee, Vince, I had the measles when they covered what standards an
> "HVLP conversion gun" needs to meet.
> In fact, the only place I've seen that term was in your clayart
> messages, so I can't comment on what it "should" have.
No point in making snippy jokes about what you don't know, Maurice. Do a
little research online you can learn all about HVLP conversion guns. If the
Geil gun calls for 30-50 PSI, then I am having a little trouble figuring out
how they can they call it a HVLP gun? The whole point of a HVLP gun is that
it has larger passages internally, and a larger spray tip, and with the
higher volume of material at a lower pressure it gives much higher transfer
rates - that refers to the amount of material that actually ends up on the
piece rather than being wasted as overspray. Conventional guns that run on
30-50 PSI create a lot more turbulence and rebound at the application
surface, and thus waste a tremendous amount of material on overspray.
Someone mentioned some sort of restriction on the inlet of the Geil gun. Is
it possible that this inlet restriction acts as a pre-set step-down
regulator? If so, it is very possible that the gun is using low pressure
internally, and specifies 30-50 PSI to get enough volume of air delivered to
the gun. Is your Harbor Freight gun also advertised as a HVLP gun? Does it
have a step-down regulator on the inlet port? Can you compare the amount of
glaze it takes to spray similar size pieces, and thus the relative amounts
of glaze lost to overspray? I'd be interested in that comparison.
Most good spray guns have that control to limit the volume of air entering
the gun, but that does not limit the pressure. The only way this Geil gun
could really be a HVLP gun is if it has a built-in step-down regulator.
Since the price is so reasonable, I think I'll go ahead and get one of the
Geil guns. Then I can compare it side-by-side with our Paasche sprayguns
and figure this out for myself.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
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