I am currently attempting to make myself a kayak paddle. I have chosen to use a carbon/Kevlar hybrid reinforcement on the front face of the paddle blades, I know that I won't be able to sand that reinforcement any after I infuse it without making a Harry mess of it so I am thinking about spraying a thin coat of epoxy onto the mold before I lay the reinforcements in to sorta after like a clear coat.  

Did he say 12-15mm for full UV protection??

No no, 12-15 'mils', or thou. Meaning 12-15 thousandths of an inch.