youre better off getting some large culm stuff , and making some hex splines. i was going to do this , till i realized my planing forms were part of a nasty breakup.
theres a guy on fleabay selling "hexaboo" or something like that. this is all that is , is large culm bamboo , split like a fly rod , planed to 60" , and glued together.
id imagine you'd have to go 3/16" to get 50#. my old fly rods were similar , but some of them the tips were very small.worked on one where the line actually went up through the tip of the rod , instead of a guide.
anyways , if you are going to try using flooring , youre best bet is to put it in the oven and toast the whole thing. id be careful though , as this will make them brittle if you mess it up...bamboo can splinter worse than carbon.
if you havent ever worked with cane or boo for arrows , id go with sulphur's idea of just getting some tow-mater stakes from lowes or wally world , and see what you can work out of those.
i used to make my fly rods out of bamboo from places like hobby stores , or tjmaxx. lots of home stores have ornamental bamboo , the thin stuff is almost always garbage , but the big stuff is nice as long as its not slathered with dye or paint , or burnt up to look "natural"...
-hov