>
> I after it had cooled off I put a piece of paper on top of the hot plate and took ∗it's∗ temperature. Just about exactly 160C.
>
> After cleaning the board up and scraping off the burnt paper I ran it
> through again and it worked fine a the dial setting of 160C.
>
> Odd, no? IR non-emission coating on the plate or something?
>
IR thermometers don't work on plain aluminum, I ran into this myself when I was building a hot plate. The temperature reported by the IR was WAY lower than that reported by a thermocouple attached to the plate.
What I ended up doing was taking a piece of 3/8" aluminum stock and boring four 0.250" holes down the side into which I inserted 60W ceramic heating elements made for soldering irons. I'm currently using an ebay PID controller to set the temperature which works very well, but I'm working on my own design that I can customize for this application.