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Fluid Air

Conventional

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I cannot trigger my spray gun. What causes this problem?
  1. Trigger safety is in the SAFETY position. Put trigger safety in SAFETY OFF position. Refer to your Instruction Manual for the operation of your particular spray gun’s safety.
  2. The gun housing may be blocked from pumping a highly viscous material with a lot of filler that has packed behind the gun needle and will not allow the gun needle to move. Disassemble and thoroughly clean the spray gun.
What parts of the spray gun require lubrication?

figure22The fluid needle packing A, the air valve packing B and the trigger bearing screw C require daily lubrication with a non-silicone/non-petroleum gun lube. The fluid needle spring D should be coated lightly with petroleum jelly or a non-silicone grease (i.e.. lithium). Lubricate each of these points after every cleaning in a gun washer.

What causes a top or bottom-heavy spray pattern?

patterns

  • Horn holes plugged – clean holes with non-metallic point (i.e.. toothpick)
  • Obstruction on top or bottom of fluid tip – clean
  • Cap and/or tip seat dirty – clean

figure20

What causes the spray pattern of my airless gun to feather?

The problem you refer to as feathering is also known as tailing. This is due to low fluid pressure at the tip. To avoid feathering or tailing, increase the fluid spray pressure by increasing the pressure at the pressure control knob. If the pressure control knob is turned all the way up you may have to thin the paint or reduce the length of airless hose being used.

How should the air cap be cleaned?

Remove the air cap from the gun and immerse it in clean solvent. If necessary, use a bristle brush to clean dried paint. Blow it dry with compressed air. If the small holes become clogged, soak the cap in clean solvent. If reaming the holes is necessary, use a toothpick, a broom straw or some other soft implement. Cleaning holes with a wire, a nail or a similar object could permanently damage the cap by enlarging the jets, resulting in a defective spray pattern.

How long should a gun last before needing to be rebuilt? What can I do to make it last longer?

This depends on what material you’re spraying and how many gallons sprayed
per day. For example, with lacquers, guns don’t need rebuilding as often because lacquers don’t have solids in them. In contrast, the high solids in blockfillers are abrasive and require more frequent gun rebuilding.

One way to increase gun life before repacking is to thoroughly clean your gun at the end of every day. Be sure to trigger the gun before removing the diffuser and when installing the diffuser. If you don’t, the diffuser will score around the ball on the new needle which can lead to premature wear. Your gun will develop a leak and this will cause spitting.

How long should a gun last before needing to be rebuilt? What can I do to make it last longer?

This depends on what material you’re spraying and how many gallons sprayed per day. For example, with lacquers, guns don’t need rebuilding as often because lacquers don’t have solids in them. In contrast, the high solids in block fillers are abrasive and require more frequent gun rebuilding.

One way to increase gun life before repacking is to thoroughly clean your gun at the end of every day. Be sure to trigger the gun before removing the diffuser and when installing the diffuser. If you don’t, the diffuser will score around the ball on the new needle which can lead to premature wear. The gun will develop a leak and this will cause spitting.

Why did my airless gun just stop spraying?

The tip may be clogged. Turn the black plastic arrow shaped handle to the unclog position (arrow facing rear of the gun). Aim the gun into a waste paint container. Squeeze the trigger for a second. Return arrow shaped handle to the spray position (arrow facing forward) to begin spraying. Always set the spray gun trigger safety when working with the spray tip.

My gun is spitting a small paint stream of paint after releasing the trigger and additional material is splattering on the surface. What’s the cause and solution?

The cause of the problem is that the needle is not seating properly in the seat. You will need to either purchase a kit for the gun needle and seat or you may only need to clean the needle and seat assembly. Residue or debris may cause the needle to move off to the side before seating.

Tip extensions, extension poles and tip filters can also cause spitting or a stream of fluid after the gun is released due to decompression of the paint trapped between the gun and the tip. Fluid pressure dissipating through the tip causes this spitting or paint stream. An automatic shut-off valve will prevent this problem.

How do I know what size needle and nozzle is best for the job?

Although every job may have slightly different requirements, for most materials it is best to choose a mid-size, or No. 3, needle and nozzle. If your paint is thicker than standard oil-based enamel, you may want to consider a larger size. Remember that there is no one tip that is perfect for all jobs. Needles and nozzles are quick and easy to change out. So try different sizes until you find what works best.