Wow!!! ridges look great :-)
I have revealed the method I use in a thread here on BPL. It is basically what is shown on the "Instructibles" site. I added a thing or two to make sure of repeatability.
There are numerous online publications that state BPA is removed from the lining of cans during the process of canning the product within them. The canning process requires the food to be placed into the cans, then heated to approximately 180 degrees for a certain length of time and then the lid is applied. During the process, the BPA leaves the lining and enters the food.
That information came out years ago. I seriously doubt that can manufactures today are using BPA in their can linings after all the public concerns that we've heard about over the years.
We are doomed to hear of complaints about BPA, Alzheimers and aluminum, wood burning stoves made of zinc plated metal and maybe some other things that I have forgotten. It will never end :-(
I have the ability to make stoves like you and flatcatgear make. I have the ability to make Caldera Cones and conical windscreens. When do you think I should start manufacturing them to be included in my store?