Just wanted to say thanks. But if I can ask* how does the growth of the zinc crystals occur sure I g this process. I melted a couple of pieces and saw nothing* my dft gauge read it as non-ferrous. These poles are 2ply with approximately 12 3/4" holes for venting. This issue is not just at the bottom of the poles near the base but extends up to 15' of a 20' pole. The single ply sections had non of these issues.