Part Two: The Gun
Now for the gun. Because primer is a thick medium, Mike recommends a gun with a 2.0 tip. Mike uses a 50-dollar gun he picked up at his local paint supply house. He says if you are just starting there is no reason to buy an ultra-expensive gun. | 
Spray Patterns
So here is a spray pattern Mike shot to show you the difference between a pin-point and full fan. When at all possible, you will want your fan to spray about a 3- to 4-inch-wide strip holding the gun about 5 to 6 inches from the panel. You will want a water trap on your compressor and about 30 psi set at the gun. | 
How To Adjust The Fan Spray
1. This is the fan adjustment knob on the gun. This is what you turn to make the fan wider. Notice the little black mark on the body of the gun. Mike uses this to keep track of his adjustments. |
2. One thing to note is the air adjustment down at the bottom of the gun. If you open the fan, you will need a little more air to make the primer come out right. If the primer is coming out very dry on the outer edges of the pattern, you have too much air. | 
How To Adjust The Paint Flow
On the right are two passes Mike made. The top one is too wet, while the lower one is too dry. Too wet will run and too dry will look like colored dust stuck to your truck, and neither one of these is good.
To adjust this, you turn the last little knob on the gun. It's on the back and it controls the amount of fluid that comes out. | 
Too WetToo Light |
With the gun set up right it should spray like this. Now you will need to focus on keeping the gun parallel to the panel and overlapping your passes by 50 percent. One more tip Mike passed on: On your final coat, add 1 more part reducer than the instructions call for to the primer. This will help it lay down nice and smooth, but you will need to reduce the air and fluid adjustments just a little. |  | |
The Final Word
If you have everything right, your primer will dry just like this and give you a nice satin finish. Obviously, Mike is a pro and he can do this in his sleep, but if you are new, just practice and it won't take long to get it right. If you are still a little scared to spray, contact Mike or a professional shop and get your ride in one color.