I handbuilt a bowl and airbrushed it with amoco blue rutile(cone 5) potter's choice on red stone cone 5 clay. This was my first attempt at airbrushing, and the glaze went on smoothly without spotting for 3 coats. there was no hint of blue after firing. There was also fine spatter on the shelf after firing. From reading past posts, I realize that the piece had no blue because the glaze was too thin. Two questions: 1) Can I heat the bowl, reairbrush with more blue rutile and gain some of the blue variation I was hoping for? 2) How can you tell when a glaze is thick enough when you airbrush? Thank you for you knowledge and willingness to share.