In this article let’s talk about High
Volume Low Pressure Spray Guns, features and how they work for you and your
automotive projects.
Traditional spray guns feature a
paint cup that is mounted beneath the gun, and which uses air pressure to blow
paint out of the cup and into the main air stream. This, in turn, blasts the
paint onto the car’s surface at tremendous air pressure. Very high pressure is
needed to suck enough paint out of the cup to produce a stroke with good
coverage. Unfortunately, this leads to as much as 70% of the paint ricocheting
off the surface and into the air.
This represents a tremendous amount
of wastage – to put it in perspective, this means that out of every 10 gallons
of auto paint shot in this manner, 7 entire gallons end up being dispersed into
the air as an aerosol mist. This wastes car paint, which is very expensive
(especially the specialty colors such as those used in candy paint schemes);
puts a large amount of dangerous paint fumes into the air, making the workspace
hazardous for the painter; and damages the environment, especially when
solvent-based paints are being shot.
High Volume Low Pressure spray guns
The new High Volume Low Pressure
(HVLP) guns, by contrast, use a lower air pressure at the gun’s tip to prevent
as much ricocheting of paint from the car’s surface during painting. Pressure
remains high at the inlet – up to 60 psi for typical painting jobs – but is
only around 10 psi (pounds per square inch) at the nozzle. The HVLP spray gun
shoots a huge amount of paint at low pressure, creating good, smooth coverage
with far less paint rebounding from the sheet metal.
With HVLP, the amount of ricochet is
halved to between 30% and 40%. In effect, HVLP reverses the old proportion.
Seven out of ten gallons shot now end up on the car’s surface, rather than
seven out of ten gallons blowing away on the breeze. This is a boon to nearly
everyone except perhaps the car paint manufacturers. You are well advised to
obtain an HVLP spray gun with a gravity feed paint cup.
One possible fringe benefit to using
an HVLP spray gun is that you will raise less of a stink while painting as
well. If you are a home painter, rather than the owner or employee of a
commercial auto painting concern where fumes are handled by a sophisticated
ventilation system, then offending your neighbors with a reek of wet paint is
always a risk. HVLP makes less of a stench and thus is less likely to bring the
wrath of the local populace down upon your head.
Gravity feed paint cups
The gravity feed paint cup is
another innovation which usually accompanies the HVLP spray gun – a paint cup
mounted above the nozzle, rather than below it, so that gravity as well as air
movement can suck paint down into the spray gun’s air stream. A special stand
is needed to hold the spray gun while the paint cup is being filled.
To learn more and to get a Free auto body and paint manual click here: http://learnautobodyandpaint.com/blog/2011/02/01/how-to-paint-using-hvlp-high-volume-low-pressure-guns/
If you want to learn about our VIP course and community click here to check it out! We currently have thousands of VIP members taking advantage of our library of step-by-step videos, private member only forums, and access to instant support from our team of VIP members and experts that can help you with your current or next auto body and paint project.
No comments:
Post a Comment