During the review of the drilling process, I determined that the Van's recommendation was to countersink the flap brace instead of the 'soft hinge' material. To do this would make the flap brace the middle of the 'sandwich' with the hinge on the underside and the wing skin on top.
In that configuration it would require dimpling the bottom skin, countersinking the flap brace and then the hinge would supposeduly sit 'flat' against the flap brace. I tested fit and then tested one hole by doing that AND dimpling the 'soft hinge' and 'dimpling' the brace after moderate countersinking. This produced a solid fit and seemed to be the overall best method of interlocking. Without dimpling the moderately countersunk brace, the skin did not sit flat, and it would require more aggressive countersinking.
The plans call for AN3-4 rivets in the hinges - first impression is that these would be 'slightly' short. Don't have AN3-4.5 but tested with -5. Will have to order some -4's and -4.5's to be able to determine proper fit.
Recv'ed the Updated Plan Set also, and the notes and annotations for the flap installation are more specific on QB v 'traditional build' rivet options, due differences in the wing skin installation sequence.
