So jealous that your Hobbytown carries Tamiya paints. They are one of my favorites for brushing, but I prefer Vallejo and Model Master acrylics for spraying. I think Too Much Garlic might be right about the mixing. The first time I used Tamiya I got some strange reactions. The second time I mixed them with my homemade dremel paint stirring attachment- 1/16 metal rod with a small bend in one end- and got much better results. What I took away from it is that once you think you have it well mixed, mix some more. Lots more.