when using a migratory top for a top entrance, do you just use a piece of plywood for the bottom board?
I don't. The frames will be resting on the plywood if you do and they will propolize them down and the bottom bars will pull off when you pull out the frames... I'd take that piece of plywood and make a 3/4" by 3/4" frame to go on top of it.
glad I asked, never even thought bout that :oops:
It's all about beespace, except that at the bottom beespace expands from the normal 1/4" to 3/8" to 1/4" to 7/8"...
could you do the same on the top but leave an opening for an entrance reducer? or would that be to much bee-space above the frames?
Top beespace is 1/4 to 3/8". More will result in more burr comb. I make my reducers 1/4" tall. usually I make them out of screen molding (1/4" by 3/4") with one nail in the middle for a pivot. I can pivot it closed or pivot it open. That way I don't lose them.
I use 3/8 to 1/2 on the bottom SBB's and 3/8 on the tops.