AIr Brush question

I have a Neo gravity feed DA brush. I'm not the best at airbrushing but i'm getting better with practice and more patience. My question is can I make it easier to get a fine line by changing the needle and tip? Is there such an option as to buy the needle and tip? I am using acrylics thined down. I still get build up on the tip. What can I do to prevent this or lessen the amount of build up?
Cheers[/h]

Acrylics tend to build up on the tip. I keep a cotton swab, dipped in Windex, handy when I'm spraying acrylics and just use it to clean the build up on the tip. It works great.

My Iwata Eclipse has the same size needle(.35 mm) as the NEO.

I don't believe Iwata sells a larger needle for the NEO but if you keep the tip clean with a cotton swab during spraying it should spray nicer.

Show me a picture of your brush. Is it double action or set and spray?

As for build up on the tip I used to have a wast basket with a wad of paper towels in the bottom and would periodically point my brush at it as I run a cleaner through (h2o in your case) it as I sprayed color or when changing to new color. should solve the build up issue.

I made a mixture that I add to my paint that I've refined over the last two years. It's made of 50% distilled water, 25% Liquitex Slow-Dri, and 25% Liquitex Flow-aid. The Flow-Aid has to be diluted first as per the instructions on the bottle or you end up with a mixture that, when added to the paint, will keep it from ever curing properly. Guess how I figured that out?!

I add one drop of this concoction to roughly every ten drops of acrylic paint in the cup of my airbrush and problems with paint drying on the tip or drying too quickly before it has a chance to level out on the model surface are gone.

The Flow-Aid reduces surface tension so the paint flows better on the surface being painted and the Slow-Dri does what it says. It slows down the drying time.

I'm still able to handle the parts in minutes and have masked within 20 minutes of painting without problems, and the paint cures perfectly.

Both Liquitex products are easily available in art supply stores or online.

I got the idea for this mix from a figure painting forum where people were talking about how to brush paint with acrylics. This mix has worked really well for me. If you give it a try I hope it helps.

As far as I know Iwata do not offer a choice of needle/nozzle sets for the Neo. The .35mm should be capable of fine lines.

The technique is to hold the air brush very close to the surface being painted and keep it moving. As mentioned above, a clean tip and the right viscosity of paint is important and generally, air brush at low pressure. Practice, and testing will (eventually in my case!) bring results.

Look at the air brush illustrators videos on youtube, you'll probably be shocked at how close they work and the fluid manner in which they wield the airbrush, almost like sketching with a pencil.