Back to the OP....I'm really curious WHY you want to know WHY it works. It reminds me of my wife asking why airplanes can fly. I can explain it in general terms, but I don't really care to because they do (airplanes, I'm still talking about), so WHY is she asking? Please understand, I'm not picking on you or your post, I'm a new honer myself, but I have more curiosity about people's thought processes than I am about WHY a proven mechanical process works.