External joining flang

I am creating a recess on the external surface of the hulls to glue glass them together.
First I use 1mm thick soft plastics (shower pan liner) glued into the mold using 3M's 77
spray glue. http://www3.3m.com/catalog/us/en001/office/mounting/node_GSBNWDW69Rbe/root_GST1T4S9TCgv/vroot_GSRCJ327Z3ge/gvel_GSTYR4LHFQgl/theme_us_mounting_3_0/command_AbcPageHandler/output_html




Then cover it with "flash tape" from Aircraft Spruce. http://www.aircraftspruce.com/catalog/cmpages/vb6045.php