Countersinking Bulkhead Side Assembly

While waiting for two back to back days of good spray painting weather and in an effort to make breaking out the spray gun worthwhile, many parts have been deburred and prepared for paint. Hoping the coming few days will pan out as forecasted so priming and top coating can FINALLY get accomplished.

In the mean while, to accommodate the flush rivets being used on the RV-12 project, the rivet holes in the flange on the F-1204CL L&R forward bulkhead side assemblies required machine countersinking where the side skins attach.

                                   Machine countersinking the flange of one of the F-1204CL forward bulkhead
                                   assemblies using the countersink cage outfitted with a #30-120 degree bit.

The seat floors will be top coated and since there are seat back hinges which attach to them,  decided to fabricate the hinges at this point in time so they can be top coated as well. The plans call for a 20 inch piece of AN257-P3 hinge … however, other builders suggest cutting 20 1/2 inches to have a ½ inch as an insurance policy. Both halves of the hinge are then cut to 10 inch lengths resulting in 4 hinge pieces. Unfortunately, the 20 1/2” piece of hinge was too big for the band saw and needed to be cut by hand.

                                   Cutting the AN257-P3 hinge pieces with a hacksaw to 10” lengths.

Once the four hinge pieces are cut to size, a line is drawn on the back side 1/4” in from the edge and one end of each hinge is marked for a #30 hole a 1/4” in from the edges.

                       Backside of hinge pieces marked for #30 hole and centerline drawn for match drilling.

                           After center punching and drilling a small pilot hole the #30 holes were drilled.

The number #30 hole that was drilled is then used to attach the hinge piece to the F-1225 seat floors. The line drawn on the back of the hinge is then centered to the holes on the seat floor, taped in place, match drilled and secured with Clecos.

One hinge done one to go … centering line drawn on back of hinge is centered in seat floor holes and match drilled.