SNJ

I don't use SNJ much anymore but have used it on past models. Never had a problem with it pooling or running. Sounds like an airbrush problem or you need more practice. Alclad II is an excellent product but is one of the harder paints to use, especially if you are relatively new to modeling. Black Undercoat works best, but you can get tonal variation by using shades of grey. You can also get excellent results with Model Master non-buffing aluminum or Floquil "Old Silver", a (gasp) model railroad paint. For my WWII NMF birds, I often spray overall with the Floquil Old Silver then mask various panels and over-spray with Model Master aluminum. Results look pretty good.

Rick