Because the DOG Aviation RV-12 is being constructed with flush rivets, the decision was made to countersink the F-1201 spacers to accommodate the dimples in the side skins and firewall flanges. The main reason for countersinking as opposed to dimpling is because the rivet holes in the cowl hinges are forward of center, so the edge of the dimples would end up at the outer edge of the F-12117 hinges … which is not my preference.
The F-1201W spacers were left Clecoed to the F-12117 lower cowl hinges and the rivet holes were machine countersunk using a #30 – 120 degree countersink bit. The countersinking process removes only a little material from the back of the F-12117 hinge so this was deemed far better than creating dimples so close to the edge.
After countersinking the lower cowl hinge components, the parts were prepped for priming along with few other small items. The plan is to use the air brush to prime both sides of the F-1201W spacers and the mating surface of the F-12117 hinges tomorrow while the weather is favorable.
