A lot of crankbaits are made out of balsa as it is very buoyant. Things to know about balsa: there are different levels of hardness/density, it is very forgiving as far as ballasting, more fragile that other wood. I have made a few crankbaits but it is tough to get both sides even on the blank. Now the only ones I make are D-Bait style out of blanks I buy from Janns or Barlows.
Allen