Jay Jay
TY for the posts here, I'm learning a lot. I too have an Iwata RG-3 and have yet to figure out how best to set it up for conssistant results. I've watched You tube videos on the subject and still don't have the hang of it yet because of all the adjustments one can make on this air gun. I use Duplicolor laquer primer bought at my local auto shop. It's inexpensive in the pint cans, readily available and works well for me.
Jay Jay, regarding the Iwata RG-3 set up… I used Paul Budzik’s YouTube video
https://youtu.be/7LKZrAokENA to set up my RG-3. Before I get started I must ask if your RG-3 is a fan cap model? If you’re not sure, please see the first picture below. My RG-3 is a standard round cap model and Paul Budzik only covers this model in his video. The standard round cap model include three nozzle sizes: RG-3L-1 (.4 mm), RG-3L-2 (.6 mm) and RG-3L-3 (1.0 mm). There are only 2 (two) adjustments on the spray gun it’s self, (1) the air cap and (2) the material flow. However, once set the air cap would only need to be changed if the viscosity of the paint material changes significantly.
1. In the video Paul suggests adjusting the air pressure at the inlet of the spray gun with an air pressure gauge, not at the air compressor. Set the air pressure with no material flow, in other words no paint or water in the paint cup. I set the air pressure with the trigger of the spray gun fully pressed and held open. To do this you need an air compressor that can deliver a constant 36 PSI of air pressure. I had to use a pancake style air compressor with a 6 gallon air tank, the type sold for small nail guns.
2. In the video Paul set his air pressure at the inlet to the spray gun between 25 – 30 PSI which is what I did; however, that required me to set the air pressure with the air compressor regulator much higher so it’s not turning on all the time. On most small air compressors the compressor will turn on automatically when the air pressure in the storage tank reaches a predetermined level. I set the pressure in my air compressor to 100 PSI in order to maintain a constant 25 – 30 PSI at the spray gun with the trigger fully pressed.
3. The next step is to set the air cap by loosening the jam nut (black knurled ring) and turning the air cap to optimize the air-paint material atomization. Paul suggested doing this with water in the paint cup and listening to the sound of spray and observing the spray pattern coming out of the nozzle. My air compressor makes so much noise I couldn’t hear any change in the sound of the spray, so I used the factory recommendation for setting the nozzle to protrude .3 – .5 mm out of the air cap. To do this I used a digital caliper set to millimeters. Please see the second and third pictures below.
4. The last step is the material flow adjustment. The adjustment knob was already set on my spray gun to 5/16” as shown in the fourth picture below, so I just left it there. Depending on what size nozzle you have (.4, .6 or 1.0 mm) you may need to change this setting to increase or decrease the volume of paint. While spraying paint I kept the spray gun at right angle to the surface being painted and approximately 8” way. I also found it helpful to press the spray gun trigger first pointed away from my model to get paint moving then make overlapping passes while holding the trigger to apply paint. Otherwise I would get a heavy shot of paint in one spot.
I hope this helps… I am 100% satisfied with the Iwata RG-3 spray gun for painting 1/35 scale model hulls, but it requires a little practice. The end result was a smooth, almost egg shell texture finish with no overspray anywhere on the model. I did have a small run trying to paint the barrel of my Sherman mainly because my paint booth is to small for this spray gun plus 8” of working space.
Harold