We spent a couple of hours painting the tuffcoat paint on the inside of the hull.
We weighed the hull afterwards and it appeared to gain less than 4 lbs of weight.
This paint is a dark gray with shredded tire rubber to make it non-slip.
It took 10 minutes to stir with a drill, thick stuff!
We put extra on the floor where our feet will be, put a light coat everywhere else.
We left some bare carbon fiber on the sides in the back for weight reduction and because it looked nice there.