this is not Rocket Science so it approximate
****WARNING**** Always wear safety glasses
Bend the angles as shown in the drawing, I just went with comfortable width of the pliers.
Bend about 1" at the bottom and loop around the pliers (or use philips screwdriver)
I drilled four holes for the screws in the cornners of my scrap O wood
I think i used #10 screws and screw them into da holes.
The C hanger is quite flexible and will adapt to most size boards. Make different size boards and add a few more C hanger to hold up.
it held well and is pretty sturdy