Welcome to the forum Brangdon.

The problem is not forming the container or setting it up on a fire. The problem is removing the foil from your kit, unfolding it and finding "pinholes" in the corners where the foil was folded.

Here are some pictures from a test I conducted.

I started with a single sheet of 12"x12" (30.48 X 30.48 cm) heavy duty aluminum foil. I formed the basic shape by folding the foil over my knee:



I then used my thumb to flatten out the bottom of the container to make a base:



And folded the top of the foil over to add strength to the creased sides:



Next I filled with 18 ounces (540 ml) of liquid. (I used iced tea for color contrast)



I then placed the filled container on the stove:



After a few minutes, a full boil:



In the field, I have had success with variations on the types of fires highlighted in green:



Probably the easiest and my favorite is this variant:



As far as the pinholes in the folds of the foil - well we'll just have to keep experimenting. [color:"pink"] [/color]