Wool coats are often expensive, which is one reason why a hole in the coat is so distressing. You can mend a hole in a wool coat and extend its life by several years. The simplest way is to use a felting technique, bonding new wool to the coat and hiding the hole.
Lay the wool coat over the foam rubber strip or foam board. Use the board for large repair areas, such as the body of the coat, and the foam rubber strip for smaller areas, such as the sleeves or collar.
Pull a small piece of wool from the large ball of wool and shape it into a circle without any holes in the middle. It should look like one solid piece. Place it on top of the hole in the coat.
Take the felting needle, and quickly pass it in and out of the felting piece, through the wool coat and into the foam piece below. Hold the needle at a 90-degree angle and keep it straight up and down the entire time. Pierce the needle through the fabric for about one minute of rapid punching in one area.
Check the progress of the felting procedure. The wool should be attached to the coat in the area where you poked the needle. Adjust the arrangement of the wool circle as necessary and continue to punch the needle through the fabric until the wool piece is firmly adhered to the base wool of the coat.