If using the CA type hinges that came with the kit. The correct gap will easilly slide a piece of typing (computer printer) paper through, but not 2 sheets.

The lines you draw ont he hinges... do them with grease pencil or crayon on both sides. Helps keep the CA from depositing in the hinge line. (this makes the hinges more flexible and they last longer)

Use the thinnest CA you can get. Medium and thick do not wick in properly and are the cause of a lot of CA hinge failures. I use "Superglue" brand because its thinner than any of the hobby CA's. It takes longer to set up too.. and that means it wicks in further. I use 6 drops per side on a precut CA hinge. Drip in 2 drops each hinge... then go back and do it again, then again. This gives time for the CA to wick in rather than run off.

When I have had a crash that pulled a rudder off... it took large hardened chunks out of the fin.