Sailor- I went to a local metal fabrication shop and they had a piece of 1/8 SS sheet left over from a previous project. I had them cut a 13 circle from it. They basically gave me the metal and told me to give the mechanic a few bucks for coffee. Nice guys! The also told me that all stainless is not created equally when it comes to magnetic properties. It has to due with the amount of iron in the composition. I think if you search ss properties you can find the properties of each type. I can't remember which type offhand but I think it was 3 something series. Anyway the shop manager told me it was OK for the application and it seems to work. Like anything new you there is a learning curve involved but it definitely smoothed out the hot spot in the middle of the plate.
