Ha! Ha! All that welding. Buy a “Fence Post Level”. At any Ace or Lowes. $3 or $4. Glue a piece of 1/4" Masonite on each side. I like to put the smooth side out on one side and the rough or back side out on the other. Choose your grit. I use 60 or 80. Glue the paper to the rough side with spray adhesive. Wa-La!! The smooth side goes on the Blank. sandpapered side trues your template. Always good to clean up the edges of the Masonite with sandpaper. I like to cut my Masonite a little bigger than the flat sides of the square. Say six inches. The square is only about four. This is another Terry Senate originally. lowel