How to Maintain Your Spray Equipment
Caring for your spray equipment is critical. By caring for your equipment properly you can use it for months and even years on end before having to completely buy a replacement for your equipment. We will discuss the important steps in properly cleaning spray equipment.
First, use the proper cleaner. Your coating supplier will provide a recommended cleaner for your spray equipment if you stray from this recommendation, you may not be able to clean at all or you may not get the equipment as clean as you would hope. Second, follow a proper cleaning method. To properly clean spray equipment will depend on the type of equipment, so this post will cover air spray equipment and then will cover airless equipment in a future post.
With air spray equipment it will depend on if your equipment is part of a pressure fed system, suction fed equipment, or gravity fed equipment. With a gravity fed spray gun you will want to empty any residual paint from the gravity cup into a waste container. You will also want to clean the gravity cup out. Next, you should run the appropriate cleaner through the fluid chamber until the fluid chamber is clear of any material, the fluid coming out will be the same as the clear color of your cleaner. Your final step should be to remove the air cap and wash it in solvent.
With a suction system the process will be similar. Empty your paint into a waste cup, clean the suction cup, place solvent in the cup, and connect the gun to air. You then spray the gun into the booth filters until the material coming from the gun is clear. Finally, you clean the air cap. This will ensure the gun has been properly cleaned.
Pressure systems are slightly different to clean than gravity and suction systems. If you have a 2 quart cup you empty the cup of all remaining material. Disconnect your cup from the air source and place solvent in the cup. You can then connect the air supply again but turn off the atomization air and leave only fluid pressure to the cup on. You should then continue running cleaner through the fluid hose until the material leaving the spray gun tip is clear (this may take a few batches of solvent). After clearing the fluid line you can place the air cap into solvent for cleaning. You should leave the fluid in the line to prevent any residual coating from hardening.
With a pressure pot of larger size you can perform a back pressure technique to remove coating from the line which will help reduce solvent use. To do this you remove all fluid pressure to the pot and remove the lid from the pot but leave the fluid tube of the lid still inside the pot. You leave the atomization air on but place your hand with some pressure over the air horns then pull the trigger to allow air to flow. Having only atomization air on and your hand over the air horns will force fluid back to the pressure pot and help save coating waste. After you have removed the most fluid possible from the fluid line you then would empty all the paint in the pressure pot. Then place clean solvent in the pressure pot and run it through your line without any atomization air but just fluid pressure until fluid coming from the fluid nozzle is clear. Your last step is again to clean the air cap in solvent, ensuring you leave the fluid in the fluid hoses.
If you are using epoxies or other material that is prone to hardening there are a few additional things to remember. You have to leave enough time to clean your equipment. Do not try to spray right up to the amount of time your material’s pot life is. Pot life is how long the material will last once mixed before it starts hardening. You may also want to do one additional step in your cleaning, clean the fluid line and fluid nozzle as mentioned above and then disassemble the spray gun’s fluid nozzle and fluid needle. This will allow you to ensure the complete fluid chamber, fluid nozzle, and fluid needle have all been properly cleaned from all material.
By properly caring for your equipment you will allow for smoother operation, better painting, and consistent finishes. A final step to complete is to routinely review your equipment for any potential need for components to be replaced. In our upcoming posts we will discuss in detail parts that are most likely to wear and some signs that they are worn.