I was using a steam generator for steaming clothes, all plastic. Our water is very pure. At work we had banks of batteries to maintain and we got tired of fussing with distilled. The boss sent away a sample of our tap water and it tested fine for batteries. So that leaves the steam pushing pigments etc. down the wood. I'm thinking that with the wood being greenish the heat expansion would push the internal moisture and pigments until it reached a cool spot. I think when I steam green wood from now on I will do the entire length. Thanks for the comments.