On the CH650 the outboard upper and lower spar cap angles are .032”.  When I rivet the area of the spar with the thinner angles it is like the swelling of rivet is puckering the hole in the angle and thus creating a few thousandths gap between the angle and the spar cap.  I have a fastener in every other hole so the pieces are clamped as tight as possible when riveting.

The inboard lower angle is .063” and I had no problem riveting that potion of the spar.  I have thought about making a doubler of .063” or making the angle(s) out of heavier material if necessary but I would rather know if this is something that I am causing.  I am using an offset riveter to do the riveting not a gun and bucking bar.

You help and comment will be most appreciated.