I have to admit to not being a fan of butts.
Actually before I begin on this topic, I need to apologise for the innuendoes you will read in my posts, I was raised on a heavy diet of “Carry On Gang” and “Benny Hill”, more a gift of my father’s father than anyone else.
A butt join is a method of fastening two pieces of timber together by ‘butting’ them up against one another and then securing the union with an identically thicknessed piece that overlaps the joint significantly (see the photo). The main problems with butt joints are that they can induce flat spots when the timber is bent and can be ugly.
My personal preference is a ‘scarf’ join (see wikipedi link), this is where the two pieces are given mirrored, feathered bevels of a ratio greater than 9:1. Meaning the bevel or scarf is at least 9 times the thickness of the timber. Commonly 12:1 and 14:1 is used. The scarf join is very elegant and demonstrates considerable skill to get it to work. My success with scarf joining is about 1 in 4…..(look closely at my Whilly Boat).
I used to be very picky about my woodworking. I steadfastly refused to use power driven screws for many years….then I woke up and smelled the ozone.
Knowing my scarfing success rate…and that the butts can be hidden…and they are not supporting tight curves, I will embrace the butt.