Rib #2 KF SS

[MotReklaw]

I'm epoxying rib 2 to my spars and shimming to get the right curve to match the bottom ribs. I'm wondering what others do to ensure a tight fit where the front of the rib touches the spar. I guess my only option is to thoroughly prep the rib and the spar before putting these two surfaces together. This seems like it would be critical area as you wouldn't want that coming loose.

Any tips?

Thanks,

[jtpitkin06]

Rib #2 is a partial rib to fit aft of the fuel tank and a cap strip that reaches under the tank to the forward spar.



A bit of planning is in order if you wish to do rib stitching on the bottom of that rib between the forward spar and the trailing edge. You will need to place your cap strip shims so they do not interfere with the rib stitch pattern. Just lay out your rib stitch spacing on the bottom of the tank in advance and place shims to avoid your future stitches.


I bonded the rib to the rear spar and the trailing edge with Hysol first to ensure the proper spacing and alignment.


To get the same contour as the bottom ribs, I used a four foot level across ribs #1 and # 3 for a straight edge. This indicated just how much shimming I needed to maintain the contour. I used the same method to trim the bottom false ribs in rib bays 1 and 2.


To hold things in position while I bonded the Plywood shims I made some temporary “mini shims” from popsicle sticks and zapped the capstrip down with a dab of hot glue. If the fit wasn’t quite right, I could pop the mini shim out and try again. Then I used Hysol to bond the permanent shims.


The front of the rib where it touches the spar was simply sanded to fit and bonded with Hysol. To curve it a bit right at the end I wet the capstrip and used a heat gun to give it a permanent set.


John Pitkin

[MotReklaw]

Thanks John. A thorough answer to solve one of my many little issues. I appreciate it!