Technical data

Table 4-1. Spray Coating Troubles, Possible Causes, and Remedies - Continued
Trouble Possible Causes Preventive Measures Or Remedies
Paint will not
come from
Spray Gun
1. Out of paint (gun begins to sputter). 1. Add paint, correctly thinned out and
strained.
2. Settled, cake pigment blocking gun tip. 2. Remove obstruction, stir paint thoroughly.
3. Grit, dirt, paint skins, etc., blocking gun
tip, fluid coatvalve or strainer.
3. Clean spray gun thoroughly and strain the
coating material. Always strain materials
before using.
Paint will not
come from Pres-
sure Tank
1. Lack of proper air pressure in the pressure
tank.
1. Check for leaks or lack of air entry. Set
correct pressure.
2. Air intake opening inside of pressure tank
lid, clogged by dried-up material.
2. This is a common trouble. Clean the open-
ing periodically.
3. Leaking gaskets on tank cover. 3. Replace with a new gasket.
Paint will not
come from Suc-
tion Cup
1. Dirty fluid tip and air cap. 1. Remove air cap and clean tip and air cap
carefully.
2. Clogged air vent on cup cover. 2. Remove the obstruction.
3. Using wrong air cap. 3. Ascertain and use correct set-up.
4. Leaky connections on fluid tube or nozzle. 4. Check for leaks under water and repair.
Excessive Material
Loss
1. Not triggering the gun at each stroke. 1. It should be a habit to release trigger after
every stroke and retrigger to begin the
next stroke.
2. Stroking at wrong angle to surface. 2. Gun should be stroked at right angles to
surface and the stroke parallel to the
surface.
3. Stroking gun too far from the surface. 3. Stroke the gun 6 to 10 inches for HVLP
gun from the surface.
4. Wrong air cap or fluid tip. 4. Ascertain and use correct set-up.
5. Depositing a film of irregular thickness. 5. Learn to calculate the depth of wet film of
finish and develop control. Measure wet
film thickness.
6. Air pressure too high. 6. Use the least amount of air necessary.
7. Fluid pressure too high. 7. Reduce pressure. If pressure keeps climb-
ing, clean regulator on pressure tank.
8. Coating material too cold. 8. Heat to enable reduced air pressure.
Excessive Spray
Fog (Figure
4-11)
1. Too high air pressure. 1. Use the least amount of air pressure nec-
essary.
2. Spraying past surface of the product. 2. Release trigger when gun passes target.
3. Wrong air cap or fluid tip. 3. Ascertain and use correct set-up.
4. Gun stroked too far from the surface. 4. Stroke the gun 6 to 10 inches for HVLP
gun from surface.
5. Material thinned out too much. 5. Add the correct amount of solvent by
measure or test.
TO 1-1-8
4-14 Change 2