Re: Top Bar width for African bees
I have used a piece of 1/4" angled wood trim for a comb guide. As far as width, the actual dimensions don't have to be real exact, just close enough that they will not gob up the comb everywhere. The will build with a very small space, abot 3/8ths inch between the combs. African or European does not matter. They are really the same bees, just different habits.
These days I just make my hives to fit a standard lang frame.
NM desert/mountain beekeeper - trying to raise locally adapted Southern Rocky Mountain bees