steam bending

Hi all, I am in the "dreaming" stages of building my perfect adventure pocket cruiser, and the closest design to my dream that I've found is Karl Stambaugh's Meadow Bird 16 for it's apparent balance of beauty, seaworthyness, and small enough to easily trailer but just big enough to spend a few...

I am planning to replace my rub rail on my Menger 17 catboat. I need about 18 feet of rail, so I will have to scarf together 3 pieces. My question is: Should I scarf and screw/glue before steaming or steam the 3 pieces and and connect the scarfs as I steam and bend the rub rail to the boat?