I know this is an often visited subject, but I promise if I'd found the answer by searching previous threads I wouldn't be posting again.
The short version: If I proceed to run the upper-skin-to-spar rivets using a back-rivet set and plate, what unseen problems am I apt to find?
Long edition: I have progressed to the point of attaching my elevator skin to the spar. From my previous query
I've figured out how to work inside the skins (in my case, wooden angle braces and a lot
of spring clamps). But as I feared, the spar riveting is a puzzle: since I have limited function in one hand, I'm not able to hold a bucking bar in the needed position under the spar while I run the gun with my good hand. On other pieces I got by with the help of gravity and a variety of wood cribbing, but I don't see that working here. One answer would be to get a rivet buddy from my local EAA chapter, but with Covid still in progress I'd rather not just yet.
So: I've been able to get some of the rivets in with a squeezer - a few on each end, and a few around each hinge hole. About a third of the total, enough to hold it together. Now I'm thinking to flip it over, stick a steel plate under it, and apply back-riveting. A careful look at the spar flange shows that it's bent a bit less than square, about 83° as I see it, which looks like enough to get the set square on the rivet. My set is a bit longer than some, so the nose of the gun is clear of the work.
plausible. What am I not anticipating?