The last few days were spent on prepping trim tab parts for priming – deburring, dimpling, countersinking, scuffing and alodining. No pictures, but it’s nothing you haven’t seen before.

When countersinking the TT spar upper flange, I match-drilled it to a piece of rectangular pine moulding before applying the countersink. The match-drilled pilot holes keep the countersink pilot centered, thus preventing the countersink from chattering and chewing up the hole.