The first thing I did out of the shoot this morning was to spray the front corners of the roll bar with weldable primer.  These corners, at the corner of the cross bar & the side rails, will get a small angle piece welded into place for a little bit of added strength.

Here’s the leftover piece of the cross bar that I cut off when I fitted the cross bar in between the side rails.  I cut 2 angled pieces out of it to create the angled corner reinforcement inserts.

Here are the inserts after I cut them out of the leftover cross bar piece.

And here they are after I welded them into place.  Technically, after I welded them in place, made a half dozen clean up welds, welded some spots that I missed, and a whole lot of grinding & disc sanding the weld junctions.

I then marked the side rails with the locations of the 1/4″ mounting bolts.  After verifying that the locations were good, I drilled the side rail mount holes 7/64″ with the roll bar off. Then I mounted the roll bar & drilled the mounting holes through the longerons.  I checked that each hole was drilled level, so that each bolt would be level when mounted.

Here’s a pic of the left side 1/4″ mounting bolts set in place.

And another front shot showing both the corner angle inserts & the 4 total 1/4″ mounting bolts.

Here are the left side mounting bolt holes shown from the outside of the fuselage.