Operating Instructions and Parts Manual | HVLP Gravity Feed Spray Gun |
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Operating Instructions and Parts Manual | HVLP Gravity Feed Spray Gun |
Instructions d’Utilisation et Manual de Pièces | Pistolet Vaporisateur à Alimentation par Gravité HVLP |
Manual de Instrucciones y Lista de Piezas | Pistola Pulverizadora HVLP Alimentada por Gravedad |
General Safety
Information
! WARNING
Do not use pressure that exceeds the operating pres- sure of any of the parts
(hoses, fittings, etc.) in the painting system.
Keep hose away
! CAUTION from sharp objects. Bursting air hoses may cause injury. Examine air hoses regularly and replace if damaged.
7.Always use a pressure regulator on the air supply to the spray gun.
Failure to install
NOTICE appropriate water/oil removal equipment may result in damage to machinery or workpiece.
Introduction
The spray gun is a vital link in any fin- ishing application. In addition to oper- ating the spray gun properly, tech- niques of surface preparation and paint preparation must be understood. These instructions will explain the differences among various spray technologies and serve as a guide in the proper opera- tion and techniques of spray painting. Refer to the Replacement Parts Manual for model specific information.
SPRAY GUN TERMS
Atomization - Conversion of bulk liq- uid to spray droplets (mist).
Bleeder – In this mode, air passes con- tinuously through the gun whether spraying or not. This mode is generally used when the air is supplied by a con- tinuously running compressor that does not have a tank.
External Mix – Process where the air and paint are mixed just after leaving the nozzle. This type of mix should be used for fast drying paints and when a high quality finish is needed.
Gravity Feed – Method of paint feed similar to the siphon feed method. However, the cup is inverted to create a positive fluid pressure at the nozzle.
Internal Mix – Process where the air and paint are mixed inside the air cap just before being sprayed. This method is best for heavy bodied, slow drying paints and can only be used with the pressure feed method. Do not use fast drying paints with internal mix. The paint will dry inside and quickly clog the air cap.
Mix – The mixing of paint and air when spraying.
Paint Tank – An auxiliary pressurized paint reservoir that allows continuous spraying of large amounts of paint with- out stopping for refills as with a canister. It also allows using the spray gun at any angle without causing paint to drip.
Pattern Control Knob – Used to form the proper pattern (size and shape) of paint as it is sprayed from the gun to the workpiece.
Pressure Feed – Method of paint feed where a canister or paint tank is pressur- ized to force paint to the gun. Either internal or external mix air caps are used with this method. Pressure feed is gener- ally used for spraying heavy bodied paints or for large size projects.
Siphon Feed – Method of paint feed where atmospheric pressure creates a partial vacuum to siphon paint to the gun. Only external mix air caps are used with this method. Siphon feed is used with light bodied paints.
Viscosity – A measurement of the resistance to the flow of liquids.
CONVENTIONAL VS. HVLP
Conventional spray guns use a much higher air cap pressure to atomize paint than HVLP spray guns. This results in more overspray and a lower transfer efficiency.
This enhanced transfer efficiency results in a significant material savings com- pared to conventional spraying. Check local, state and national regulations that may be in effect before perform- ing any spraying operations.
HVLP spraying is a growing trend in
the finishing industry due to its environmental
friendliness. By definition, dynamic air pres-
sures in the air cap must be 10
psi or less to qual- ify as HVLP. A
soft, low velocity pattern is produced which increases control and reduces bounceback and overspray (See Figure 1). For these reasons, HVLP is also well suited for spraying parts with recessed areas.
Spray Gun Set-up
The pressure for atomization is con- trolled at the air source. The amount of fluid is adjusted by the fluid control knob, the paint viscosity and the air pressure.
The gravity feed cup screws onto the top of the gun body creating a positive fluid pressure in the nozzle (See Figure 2).
Filtered,
Regulated
Air Source
Figure 2 - Gravity Feed Cup Set-up
Notes Notas
Feed – Method used to bring paint into | HVLP, electrostatic and airless processes | Preparation | |
the gun for spraying. | are currently the only compliant spray | 1. Thoroughly mix and thin paint in | |
Fluid Control Knob – Used to control | methods that meet the strict 65% | ||
accordance with the paint manufac- | |||
the amount of paint being mixed with | transfer efficiency criteria required by | turer’s instructions. Most materials | |
air. | some air quality management districts. | will spray readily if thinned | |
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