Riveting Root Ribs?

[Phil]

Anyone have a slick way to secure the double root ribs while driving the rivets for the stiffeners? I tried just clamping the flange to the edge of my work bench and ended up drilling out 3 of the first 5 rivets I attempted. Not a good average.
Thanks.

[N3UW]

I used a back rivet tool for all the riveting on the center rib stiffeners. I drilled a hole in a large chunk to hold the die for the factory head. the back rivet tool in my 2x rivet gun has a spring loaded collar that also tends to hold the material together.

[Phil]

How did you use that for the root ribs with stiffeners on both sides?

[Phil]

Final solution was simply a spacer or 3/4" ply so I could clamp it to the edge of my work bench.