We started using an Iwata spray gun several years ago at the school that I teach at. After using the gun, I was sold on it. Most students that have no preference choose the Iwata as their gun of choice as well. So if you’re looking to purchase a new gun, I recommend an Iwata spray gun. The Supernova with a 1.3 is my favorite. However, the tips that I am going to share with you can be applied with any spray gun.
1. Adjust The Air Pressure The first thing that I normally do is to set the air pressure. Be sure to look at the technical data sheet for the product that you will be spraying. This data sheet will give you a recommended air pressure setting. However, pay attention if it states at the gun or at the nozzle. Big difference. If it says 10 cfm at the nozzle and you set it to 10 entering the gun, you’re going to have problems. You will not have enough air pressure, which will result in the paint not atomizing correctly and have excessive orange peel.
Using my Iwata, I use an air regulator on the end of my gun. I set it anywhere from 18 to 24 psi. This usually work great for most coatings. As mentioned, too little will under atomize (orange peel) and too much air pressure will over atomize. This will cause too much over spray wasting paint and causing the over spray to land back onto the surface causing the paint to look dry.
2. Adjust The Pattern The pattern adjustment will adjust the pattern from a small ball to a wide fan shape. If the pattern is not wide enough, you are going to have runs and stripes in you paint job. If the pattern is too wide, you may have poor coverage and waste paint materials. With the Iwata spray gun I normally open the pattern open all of the way. Then I start closing the adjustment until I start to see the pattern start to get smaller. Once it is to that point, I stop and make my next adjustment.
3. Fluid Adjustment This is going to depend on the product being sprayed. For clear coat I open the adjustment to maximum to allow a lot of fluid to come out. If I am shooting base coat, I will adjust and close the knob about 3 or 4 turn to allow less fluid to be sprayed.
4. Fine Tuning I have the gun set, but it needs to be fine tuned to my techniques. First, the additional adjustments may have changes my air pressure, so I will readjust the psi if needed. Next I will spray a test pattern on our spray cart. If it is runs or looks too thick I will widen the pattern. If it is not covering well I will narrow my pattern. Lastly, I will adjust the amount of fluid. If it feels like too much I will adjust for less fluid and if it does not feel like enough fluid is coming out, I will increase the fluid adjustment.
5. Practice The last tip that I can give you is to practice. That is what it takes and do not be afraid to make adjustments. Make your spray gun fit your technique, instead you adjusting your technique to fit the paint gun. This tutorial was with an Iwata Spray Gun in mind, but any other paint gun that you may be using will follow the same steps.
by Donnie Smith