Duplicolor coming out powdery

[Txdwn1]

Wondering if anyone else had a problem with the Duplicolor Paint Shop Finish Gloss Clear Coat spraying fine for a few moments then looking powdery? Did everything the directions said to do, cleaned the spray nozel to make sure it wasnt dirty and tried again. Again it sprayed for a bit normal then back to a powdery look. Any ideas?

[CFarias]

I use the same system for my primer and certain paints. I don't use the gloss clear but I've had the same experience. The clear is drying before it gets to the model.

Try using a larger nozzle. I have better success with hi-flow nozzles on my airbrush.

Try thinning the clear. I thin down to 1 part paint and 2 parts acetone. It sound that I'm really thinning down the paint but it works for me. This will also mean more painting sessions to get the desired build-up of clear, but the finish should be deeper and richer for it.

Try adjusting the pressure. The powdering can sometimes be resolved by lowering the pressure. I've lowered mine down to 25 psi but I've had it work well up to 35 psi.

Try spraying closer to your work. That way the clear has a better chance of getting to the model before drying on the way there. Carefull not to make the paint run!

Follow the steps in the order above and only try one at a time. When you've got it figured out write down your paint ratio, pressure setting, and nozzle size for easy reference later.

Hope this helps.

[CFarias]

P.S.: The reason why your are getting intermittant results is most likely because of a buildup of clear on your nozzle as you spray.

The velocity of the clear coming out of the airbrush is initially good enough to produce no powdering, but as the clear builds up at the tip of your airbrush it increases the velocity of the spray, causing it to dry prematurely. Paint delivered at a higher velocity will have a greater chance of powdering than one delivered at a lower velocity. It's that old "put your thumb over the end of a water hose" analogy.

That being said, thinning the clear instead of backing off the pressure to slow the velocity is the easiest and most forgiving adjustment that can be made so do that first.