Hi, I am thinking of installing some "porcupine wire" (brand name 'nixalite' or something similar) around the trunk of my Magnolia tree. The crown of the tree is about 33' wide and the raccoons are climbing the tree to access my porch roof, then chewing on my house. I can't really prune far enough away from the house because one of the main structural branches is very close to the house and I don't want to cut it. My question is, would hammering the nails required to install the product (maybe 30 or so galvanized nails) be harmful to the tree? (And if the nails are bad, then are there any other suggestions about how to outfit the tree so the critters can't climb it?) Thanks.