I'm not an engineer so it shouldn't surprise anyone that I have no clue at all about how much load is imposed on this part or that.
But I'm going to guess there must be a hell of a lot of it on the most aft bulkhead. You have to rivet in a doubler plate (didn't check but it's either .063 or .090, judging by experience) into the aft bulkhead on the RV-12. to which the tie-down bracket (mentioned in yesterday's log) is eventually riveted.
Look at how many rivets that takes
I sold my rivet gun when I finished the RV-7A. Heck, I wasn't going to need one anymore, so I'm using a TATCO hand squeezer to set all of these.
Edge forming tool arrived from Cleaveland Tools.
It's one of those times I hurt myself patting myself on the back for buying a longeron yoke way back when.