After the tie down ring was completed, began working on the tail cone’s aft bulkhead doubler plate which required the removal of four manufacturing tabs on the band saw and some serious deburring …. the metal required lots of filing and sanding to remove all the burrs from manufacturing.
edges of the slots on the bulkhead doubler plate.
Once the edges and cutouts on the doubler plate were all smooth, the countersink bits were brought out for the 16 #40 and 3 #30 holes that require machine countersinking.
A couple of days ago while digging out the rivet gun I ran across a bottle of liquid Boelube I forgot about purchasing way back in March. For those not acquainted with Boelube, it is a lubricant Boeing came up with for use on drill bits and cutting tools to make them last longer and it seems to make the drill cut better as well. The form I’m most familiar with comes in a plastic container and has the consistency of crumbly wax. As the drill bit spins, it has a tendency of flying off the drill bit and getting it on a countersink blade is … well, problematic at best. The upside is that it is a dry lubricant and does not leave an oily mess after the hole is drilled.
The liquid Boelube is more of an actual lubricant and performed great while cutting the threads into the AEX tie down extrusion which the tie down ring will screw into. I also placed a drop on each hole that was countersunk and had great results.
the liquid Boelube used on the holes prior to countersinking.
