Start with a solid figure of any kind with at least 2 faces. (this includes any 3 dimensional figure excluding a sphere)
Select the side of the figure that you wish to shell from. This side will be removed by the shelling process. (do not select a curved side as this will not shell.)
Select “SHELL”. This icon is highlighted in the photo above.
Select your wall thickness. (the thickness must be no more than half the length/width/height of any given portion of the part or the shell will not work correctly)
Select “OK”. This icon is highlighted in the photo above.