1.Make a hat block. This will provide you a base onto which you will shape your felt hat.
Glue several pieces of styrofoam blocks together. You may need as many as 3 or 4, depending on how big you want your hat to be. Allow the glue to dry before proceeding.
Carve your hat block out of the styrofoam. The size and shape of the felt hat you wish to make will determine the block's size and should be at least the size of your head. The hat block will determine the size and shape of the crown of your felt hat.
Coat the styrofoam hat block with white glue with a 1 inch (2.54 cm) paintbrush. Allow the glue on the block to dry before moving on to the next step.
2. Cover the hat block with saran wrap. This will keep the inside of your felt hat clean. Pin the wrap at the bottom of the block using T-pins. Secure the saran wrap further by wrapping a rubber band at the pin line.
3. Cut the felt into 2 circles. Each circle should have a diameter 3 inches (7.62 cm) wider than the widest part of the styrofoam hat block.
4. Form the top of your felt hat. To do this, you will be stretching the felt over the styrofoam hat block.
Soak the felt in water. The felt should be completely wet, as opposed to marginally damp.
Center the wet felt on the hat block. Secure it with a T-pin at the center to keep it in place.
Stretch the felt over the hat block. Do so gently, so as to not damage the felt. As you stretch it, place T-pins evenly around the base of the styrofoam hat block.
Remove the top T-pin from the felt and styrofoam hat block. Leave the T-pins around the base intact for now.
Stretch the felt again, pulling harder. Continue to stretch your felt hat, placing T-pins every inch or so. When this step is complete, the amount of felt below the pin line should be even. Wrap a rubber band at the pin line to further secure the felt.
Coat the felt with white glue using a 1 inch paintbrush (2.54 cm).
Wet the second circle of felt before placing it over the first. Repeat the steps to stretch the second circle. Do not coat the second circle with glue after it is stretched. Allow the crown of the felt hat to dry.
Remove the felt crown from the hat block. With a pair of scissors, trim the excess felt off of the bottom.
5. Make a felt hat brim.
Cut out 2 pieces of felt of the same size for your brim. No matter the size you want the brim to be, add 2 inches (5.08 cm) to your measurement.
Dampen each piece of felt for the brim. Coat 1 with white glue. Press them together to form a double layer, using a hot iron. Be sure to first cover the felt with a press cloth to protect it from the heat of the iron.
Cut a circular hole in the center of the brim. The whole should be 1 inch (2.54 cm) wider in diameter than the base of the felt hat crown.
6. Attach the felt hat brim to the crown. Put the crown back onto the hat block and pull the brim down over it. Secure the brim with T-pins.
7. Using either heavy-duty silk or wool thread, sew the brim to the crown, permanently securing the crown and brim together. Remove the T-pins.