marking the bulkheads

Since the foam strips are 3/4 in. thick, I made a scribing tool with a piece of scrap foam and a sharpy pen. Once I have my mark, I cut the excess off the edges of the bulkhead with a saber saw fitted with a carbide grit blade. ( I mark both sides because the hull is not always at a right angle to the bulkhead and when I make the cut, I set the saw blade at an angle and try to cut to the lines on both sides of the bulkhead ) Since I use plenty of epoxy fill when I make th join, it dosen't have to be perfect.