After tracing the leading edge onto the graph paper I need to draw a smaller section that included the offset for the thickness of the 1/8" plexiglas, the 3/32" thick plywood that would span between the two forms to be made and the cotton flannel that the plexiglas is in contact with while it is being formed. After doing some quick math I set my dial calipers to 0.245" and worked my way around the leading edge every half inch or so making a dot to represent the desired offset. Then I used the ships curves (some would call them french curves but at school we were told that the proper name was ships curves) to connect the dots in a "best fit" exercise. Then I took them to my nearby FedEx Kinks to have the new shape reproduced on cardstock. I'll cut out the cardstock and use that as a template to draw the leading edge shape onto some 1 x 8 poplar I have in my garage.
Leading Edge as Traced onto Graph Paper
The Offset Line was Drawn with the Aid of my Dial Calipers
Connecting the Dots My Old Ships Curves Purchased When I was a Freshman Engineering Student at SMU