In this photo the thru-hull has been fully tightened using a thru-hull step wrench and a large adjustable wrench. I torque it down fairly well into the seacock.
When fully torqued you will have squeezed out quite a bit of sealant.
I love all your articles, but I was hoping you might expand this one. I'm wondering what you would do different if the boat was cored below the water line. I'm assuming you would do some kind of Epoxy sleeve to protect the core material in the event of a leak?