Glue

(If you are going to add another piece of leather for a reinforced lip then now is the time to do it, before gluing the two halves together. Keep on reading, you'll get to the sewing in a sec.)

Next we want to glue it. I like to use super glue (CA glue) cause I have plenty of it around the shop for wood turning. Leather glue works great too but the CA glue dries almost instantly and is plenty strong.