A weather vane is used to show which way the wind is blowing, and is generally found at the highest point of a building. While weather vanes do serve a purpose, most of them are used for decoration. Metal is used for some weather vanes instead of wood because of its durability. Wood may crack or break within two or three years, but metal weather vanes are capable of lasting decades, if not longer.
Mark off a 2-foot portion of metal pipe using your grease pencil.
Use your hacksaw to cut through the metal pipe, leaving you with two 2-foot pieces.
Drill through the middle of the metal pipe using the 1/2-inch drill bit. Drill slowly so that you don't collapse the center of the pipe, and make sure you go all the way through both sides.
Use your grease pencil to draw a triangle on your metal sheet. This will be the head of your arrow. Draw a second triangle beside it, with a smaller, third triangle inside the second triangle.
Cut out each of the triangles using the tin snips. Discard the third triangle. You should now have your first triangle (the head of your arrow) and the second triangle, which will be the back of the arrow (and will look like it provided the third triangle is removed).
Use the tin snips to cut a small slit on the bottom of your first triangle and another small slit at the top of your second triangle.
Paint each end of your 2-foot metal pipe using the metal cement. Slip the top of your arrow over one side, and the bottom of the arrow over the other side of your metal pipe. Let this cure overnight.
Use your rubber mallet to pound a piece of rebar into the ground where you would like your weather vane to be.
Slide your extra metal pipe (the one that does not have the metal arrows cemented to it) over the rebar.
Place the steel washer on top.
Place your weather vane on over the rebar, using the hole that you drilled in the middle of the copper pipe. Thanks to the steel washer, it will be able to spin freely when the wind blows.