I designed the tailplane flaps in CAD and laser cut them from ply, with balsa blocks for the hinge points.
Forgot to mention that I was now spraying the mold with 2-part car primer to produce pre-primed parts in an attempt to conserve the surface detail and not have them be lost in multiple layers of final priming. That worked well from the beginning.
I laid up the tailplane with a layer of 2oz and 4oz glass cloth with a carbon strip for the trailing edge, all vacuum bagged.
Bonding in the internal structure I used a thickened mixture of epoxy, applied using a small zip-lock bag with the corner cut off, much like a icing piping bag.
I was really happy how the final tailplane flaps turned out.
