REDhat said.. 7/16 unf tap is 11.13 mm major diam and 9.73 root diam. Assuming that is a 10m1.5 pitch o-ring plug that is stripped. The od of a 10m1.5 helicoil is about 11.7mm. Thread tape will not have any shear strength needed to clamp an o-ring. The torque required to tap a new thread may exceed the bond strength. A new (sharp) tap and a careful hand would help. Any consideration to any windsurfing standard thread type is not relevant. Their is a risk the od of the brass insert may not be enough to tap to 7/16.
REDhat said.. 7/16 unf tap is 11.13 mm major diam and 9.73 root diam. Assuming that is a 10m1.5 pitch o-ring plug that is stripped. The od of a 10m1.5 helicoil is about 11.7mm. Thread tape will not have any shear strength needed to clamp an o-ring. The torque required to tap a new thread may exceed the bond strength. A new (sharp) tap and a careful hand would help. Any consideration to any windsurfing standard thread type is not relevant. Their is a risk the od of the brass insert may not be enough to tap to 7/16.
It seems to be a finbox screw thread that is the problem, from the picture, not an o-ring plug.
