Hi all, I need some advice - our art center uses a spray gun (industrial spray gun ) to spray ceramic glaze on pottery; the man that does it most of the time that has the information is never there when I am and I can't get much information on how it is done - or I guess answers to the main question I have.   I want to "layer" paints....but what I am wanting to know, I don't currently have a spray gun and need to go buy one at harbor freight; but I am just planning on using food safe undergla