I construct screen bottom boards using standard "face frame" cabinet building tools and techniques.
In essence, I sandwich a "screen door" frame to a bottom frame. Frames are constructed using a biscuit joiner. The resulting assembly leaves a "drawer slot" and strenghtens the side rails to support the hive.
My construction is detailed with photo and a parts list in pdf I have uploaded to:
https://docs.google.com/leaf?id=0B3H7Ru-k1dP3MWUzYTg2MmEtNWM3MC00MzU1LTk1YWItODIyOTMwM2I5ZDA5&hl=en
All you need for this one is a tablesaw
http://www.myoldtools.com/Bees/bottomboard/bottomboard.htm (http://www.myoldtools.com/Bees/bottomboard/bottomboard.htm)
BEE HAPPY Jim 134 :)