Once you have mastered the basics of your spray guns, you must become adept at adjusting the spray pattern through the fluid flow. Many of the guns have built in air micrometers, which allow variation in the pressure settings. If your particular gun does not have this then you can use a separate air micrometer. The width of the spray pattern is controlled by the fan. The majority of painters like to use a wide fan but it must be remembered that the wider the fan the less material is being distributed.
Many novice painters will complain about large droplets. This is rectified by either adjusting the fluid needle so it lets less liquid through or use more air pressure.
You will not find this applicable with HVLP guns. They only contain 10psi to atomize. Most of them use integrated air converter. The manufacturer will provide you with the proper inlet pressure to set the air pressure cap. This is done after you have set the fluid control and chosen the appropriate nozzle.
To get the very best performance from your HVLP gun at the air inlet slowly increase the pressure and vary the control of the fan. You can do this easily with an accessory air cap. It has dual gauges, which allows you to check the center as well as the horn air cap pressures.
The reason that high performance from the spray gun is so critical is because many of the new paints on the market contain low VOC and high solids material. Atomization becomes increasingly difficult as the volume of paint increases.
Now that you have your gun ready to do the perfect, job its all up to you. If you are not precise with your painting, you are going to get runs, pitting and mottling.
You must be in control of your spray gun at all times in the following areas…
a) Judging the correct distance from the gun to the object
b) Proper trigger action
c) Control of the speed at which you are working
d) The angle at which you hold the gun. This requires techniques such as heeling toeing and fanning.
e) Constantly watch what you are doing so you apply evenly. Do a perpendicular pass at a constant even speed. If you go slowly, you will apply more paint whereas if you go fast you will decrease the amount.
f) Make sure you are wetting the surface
g) Each pass must overlap the previous application by about 50%
h) Make sure you don’t double pass the same area
If you observe a problem let the paint flash and fix the problem on the second pass. There will be some flow after application but this will depend on the amount of reducer and hardener you have used. Once the paint catalyzes though whatever is showing is what will remain until you correct it.
Remember to take your time follow all the steps and you will master any weaknesses you have with your spray painting in no time with practice.
I would be remiss if I didn’t take the time to thank you, my faithful readers for visiting our site and reading Car Spray Guns 101 – Learning the Basics of Spray-Paint Gun Operation . I truly appreciate you!