Mike,
I use a piece of 3/4" particleboard, I make a slit in it lenghtwise on my table saw, almost all the way through, and then I use short sections of brass stock, about 1/32" thick, by 1/2" wide, and about an inch and a half long. I put the brass in the slit, and in the hinge pockets on the control surface. Then I wedge the brass into the table saw kerf with scrap balsa and a drop of CA to lock it in. I make separate pieces for each surface normally about two inches wide, that way I can spray Up onto the hinge face while painting.