Fiver, there's a difference between understanding the properties of what you're working with and manipulating things to work for you (or leaving them alone) and not knowing or understanding. Gadgets can be good and they can also be a pita or get in the way. I do better with a casting thermometer than without, mainly because I have a cheap furnace that needs a tweak on the t-stat once in a while and the moulds do care if the alloy temperature swings off course. So do the rifles. Casting is like driving, after a while of looking at readouts, dials, scrutinizing every cast for defects, etc. you learn what to look for and sorta go on autopilot. If the pot will hold temperature where you put it and where you know it works, all you have to do is watch the sprue and that only takes the two gadgets you were born with. If guys want to use a PID on their pots and a temp probe hanging out of the end of their mould blocks, more power to them. I got rid of my PID years ago, more trouble for me than it was worth, and the SSR cost more than the furnace. When it fried, I punted it and went back to the Tel-True.