OT: (a little) Flattening a griddle

I'm really big on breakfasts, and love cooking on cast iron. But almost ALL the cast iron skillets I've bought have a slight crown.

Now, I pick one that has enough 'meat' in the center to allow a bit of grinding, and take out the crown abrasively. Ideally you want just a little 'dish' in the center.

But I don't think the crown is accidental. Think about it. If the thing were dished, it wouldn't sit stably on a burner. By grinding the dish, you keep the 'dish' on the bottom, as well. Forming it would make the bottom convex.

Cast iron skillets don't like to be cold-formed, and don't hot form well unless you get the whole skillet up to working temp... otherwise they often crack.

LLoyd

If it's steel or aluminum (NOT cast Iron!) you can readily beat it flat with a wooden hammer IF you learn the technique. The idea is to cold flow the metal with lots of small taps. Use a wooden anvil and a wood or plastic or rubber hammer and hit at a small angle from vertical and with patience the metal will flow and you can get it perfectly flat. The reason it is crowned is that heat treatment (cooking on it) has selectively stretched the metal so there is too much of it in the center so it has to crown up. Move a bit of it away fron the center and you will be amazed at how fast you can flatten it. You might practice on aluminum, it works easier.

Of coures, eventually the heat of cooking will re-crown the bottom but you can flatten it again. You cannot force it flat in a press because there is too much metal and all you can do is flip the crown into a dish.

I flattened my commercial aluminum frying pan with a rubber hammer. Karl