Help needed to make a big spoiler side panels, how to take mold?

Hi guys, need sum help here.
Got to make this spoiler. Its 3 part. 2 side panels and 1 blade ( main spoiler bit)
The side panels got to a be certain thickness to be rigid.
This needs to ne frp not carbon. So im planning to make with wovenglass and soric lantor and do a resin infusion.
My question is how i can seal the edge of the blades? They are pretty easy panels to get the molds.
Kinda confused as how to make make molds and how do i make the edges sealed and smooth?
Or any other way to make this panels?
Cheers