I just started using my new Iwata HP-CS for the first time the other day. This is my first time to ever use an airbrush, so please forgive my lack of knowledge in this area. The first time I ran paint through it, it seemed to do OK. The next time I used it, it seemed to spit large large paint particles out a little bit. I cleaned the airbrush very well after using it the first time. I’m spraying Model Master enamels properly thinned through the airbrush, about 3 to 1 ratio using Testors airbrush thinner. Anyone know what might be the problem? On dual-action airbrushes, do you ALWAYS depress the trigger and let the air flow all the time, and just pull back on the trigger when you want to release the paint or what? When I cleaned it, I took the needle out and cleaned it with mineral spirits, and then lubed the needle with Medea airbrush lube. If you are spraying the same color and waiting about 30 minutes between sessions, is it necessary to clean out the paint cup and clean the nozzle before beginning again? Any thoughts, recommendations, or "hey, dumb@$$"es appreciated!!
When using an airbrush the proper technique for spaying is to leave the air on (trigger depressed) and then rock the lever back to control the amount of paint you want to spray. This helps in two ways. First you only have to be concerned with one movement of the lever and second it will keep the end of the needle clean. If you get a paint buildup on the end of the needle it can cause the paint to spatter because you are changing the airflow around the tip of the needle and won’t get the proper atomization. In response to your second question about spraying one coat and then waiting a little while before applying another, the paint in the cup should still be thin enough to spray.
Where you run into a problem is around the needle because the small amount of paint starts to dry. The trick I learned when shooting acrylics was to keep a small container of thinner nearby with a short bristled brush. After every short spaying period, dip the brush into the thinner and gently daub around the needle to disolve any dried up paint. Then pointing the airbrush away from the model, give it a shot of air and that will blow off the thinner and any built up paint. Then resume spraying. I will use this same technique with enamels if I have a large area to do and there won’t be constant spraying. One other thing that you have to be careful of is when you are disassembling your airbrush and removing the needle be very careful that you don’t put even the tiniest little bend on the end of the needle or else you will get a spatter because the airflow is trying to blow over this little hook and it’s disrupting the flow. I hope this info helps out.
gbritnell
Good advice gbritnell.
You can also use a Q-tip moisened with some thinner to clean the tip and needle if it becomes too dry. The Q-tips with the hollow stem work best but you can also take the cotton of a regular cotton swab and pull it toward the end of the Q-tip fluffing it up a bit which will give you more area of cotton to clean the tip with.
As was mentioned, the trick to end spitting paint on your surface is to always point the airbrush away from the surface you are painting and push down on the trigger for air only which will blow the excess paint off the tip. Then you can start spraying on your surface again.
Mike
One other thought is the paint to thinner ratio. For most modelers a good starting formula is generally 2 parts paint to 1 part thinner. I use eye-droppers full to measure the “part”. I also always use the MM Airbrush Thinner for their enames for airbrushing. It sounds like your cleaning your HP-CS well… try the afore mentioned ratios and get back to us with your results. Good luck!
Good point Greg. He may be spraying with paint too thick at 3:1.
Mike
Many thanks for the good advice. Like I said, I’m a newcomer to the airbrushing world. I read somewhere that one person uses a q-tip moistened in thinner to reach down into the cup mounted on the top of the airbrush in order to clean this part. I tried this and found that the q-tip catches a little at the bottom of the cup, I guess because it’s not perfectly smooth, and leaves little strings of cotton behind, which I would think would clog up the nozzle, too. I need to get me some airbrush cleaning brushes!!
Bear Air has these for $19.95:
Coast Airbrush is cheaper at $17.95.
Mike