Got my hole cut out for the deck plate. Jigsaw with a fine tooth metal saw worked great. Had read that carbide grit was good too but didn't have one of those so thought I'd try what I had with a test cut. Absolutely no reason to go out and get a carbide grit blade if you don't have one. The thickness is just shy of 1", so the bolts to go through the deck and the 3/4" flange should be # 10 2" or so. The screws I got for the deck plate are # 10 3/4". Currently waiting for my epoxy to dry where I chipped out the balsa. I used a combo of an ice pick type tool and a small chisel, both with a mallet. And also just scraping with them. I tried to dig deep enough that my drilled holes will also go through epoxy instead of balsa. I used the West System Six 10 thickened epoxy in a caulk gun. It is plenty thick enough to stay in place. I pushed and formed it in with the West System stirring sticks (tongue depressor looking things). Check out my post about it all here
http://funonholiday.com/index.php/2016/ ... ing-masts/