Today I cut and installed the ribs that will support the fabric on the left horizontal stabiliser. These are fabricated from 3/8" "Piper" channel which is mild steel 0.019" thin!These were cut approximately to length and then the fronts tack welded together at the angle required to curve nicely towards the main spar. The front was then cut to the angle of the leading edge and notched to fit round it. The ribs were then bent gently around a spare length of the spar tubing to meet at the rear. They were then test installed and the rear cut to accurate length allowing for notching round the rear spar. The ribs were then installed and tack welded to the leading edge and rear spar to hold them in place. This required very low currents with the thin material so rather than welding the complete joints they were brazed to complete them. Finally the ribs were brazed to the main spar.
