Then I slid the inner plastic portion of the flex duct back on to the adaptor and put on a tie wrap to hold it in place.
Then another layer of Mastic over the duct to help seal things up.
Pulling the fiberglass back down and getting it covering the whole joint.
Then pulling the outer layer of the ductwork down and putting the last tie wrap in place.
I have finished about half of the house. I am doing both joints at either end of the flex.