HI there! I came across your hatch post which is so helpful...we worked on ours and the first round our sheet metal rusted - boo...and then leaked. yikes! we are trying galvanized this time and i'm hoping that will work. when you put down the butyl tape do you do it on top of the seam once the metal is sealed down? I couldn't quite tell from your steps and picture since you mentioned tape before screws...it looked like the picture showed tape around the outside. Thank so much for your help!