just finished a tinjo when i cut the can i left the brim intact but still was able to cut out the grove for the neck to pass through this way the brim can act as a ring tone i found that this eleminates the (twang) you get from the vibration when playing the tinjo..also i made fret bars on the neck from windsheild wipers when cut for fret bars bend them enough to create a little bit of a bow so that when you insert these into the fret bar grooves the bow will hold them in place so there is no mess from glue or epoxy on the finished surface of your finger board and neck area