Superdave95, my favorites' are horseweed with a soft whitepine hearth board, question for ya, when you say Poplar are you referring to Yellow poplar ( tulip poplar) or Aspen type poplars (quaking or big tooth aspens types) I know both will work just wondering about your thoughts on Tulip poplars, I have had some issues on the tulip poplars, Ijust curious with your take on them. am not a big fan of them but they are mentioned often as good materials. Mullein is my second go to spindle works real well and is plentiful also . I really like the bigger mulleins for the bow drill, makes for easy coals. I just saw that you were commenting with Ed on the milkweed and had a another question for ya. Have you ever used milkweed ovum with flint and steel, If not give it a try and see how it works for ya, good coal just doesn't last long is my take. Later Bob