>James, from the Car mechanics magazines I read now and then, paint shops
>are having to go over to High Volume Low Pressure systems due to a
>change in the law. I don't know the reasoning behind it, but I believe
>you do need new nozzles, paints etc.
>Mike
Hi guy, I said I would go thru this as thoroughly as I could, so here it
is. Starting at the top . Compressors. CFM is cubic feet per minute. This
is the volume or flow of air. PSI is pounds per square inch, or force. The
free air delivery is the actual air flow in CFM which is dictated by your
compressor's hp. As a rule one (1) horsepower is good for 4 CFM. More on
CFM later. Spray guns. Three types to be concerned with. Gravity feed.
Siphon feed. Pressure feed.(pot type) And which, HVLP, or
conventional,(high pressure). Gun requirements vary from conventional= 40
to 70 PSI, 8 to 11 CFM. HVLP= 18 to 80 PSI, 13 to 28 CFM. For you folks
thinking about HVLP that translates to a 5 HP compressor minimum! Take
heart there is a solution. A lot of the HVLP systems on the market can be
purchased with a turbine power unit. These units work great. I have had the
pleasure of using a system made by a company called Fastech
(847)836-1633(u.s.) It's called the citation. It also has a built in fresh
air respirator. A must for isocyanate containing products. It's available
with either a Lexaire or a Accuspray gun. This unit puts out 110 CFM at the
unit. But they must be put in a clean air environment. Also you should use
1 step slower reducer than normal as these units also heat the air. ie-
---From mediun to slow reducer. Otherwise your paint will dry too fast.
(another cause of orange peel). Now. On to paint. Volatile organic
compound, or known as VOC's. The burden of VOC compliance has been placed
on the manufacturers of refinish coatings. This means that we cannot
manufacture products that are not compliant. The national rule (U.S.) Is
not going to require the use of HVLP equipment. Unless you live in one of
the restricted areas such as Los Angeles, Louisville KY., Houston Tx. ect,
you can spray with what you please. even if you live in L.A. you could buy
a spraygun of choice out of state for your personal use. Most important
IMHO is spraygun setup. I could REALLY get long winded here but, you need
the proper fluid needle, fluid nozzle, and air cap for the products you are
spraying. What works for one product may not work with another. What works
for high build primer will probably not be the best chioce for your
topcoat. Pay attention to air pressures on any gun type. Go with the paint
manufactures recommedation's whenever possible. I hope this helps you
gent's a little. If you think of something I've missed, let me know. Thanks
for listening.
Jim Thursby
N814AT
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