So I'm currently in the midst of doing all the riveting of my fuselage canoe. I managed to shoot a large proportion of the rivets by myself, which kind of reflects how I've worked on most of the project - I do stuff solo whenever possible.
Fortunately for me, my lovely partner also flies and is interested in the build, so she's a very willing helper. Among other work, we shot all of the top wing skin rivets together - me shooting, her bucking. It was tedious at times (pretty much the running story of wing building), but we got through it pretty painlessly.
When it came time to flip the canoe over and get back to team riveting, I decided to switch roles - rather than asking her to crawl under the canoe and perform all the contortions, I let her stand outside and run the rivet gun. We made steady but slow progress, but she had a hard time controlling the rivet gun, and so numerous rivets got overdriven and had to be replaced. I was frustrated because I felt like she wasn't concentrating on doing the job right, and she was frustrated because, well, she wanted to help and it wasn't going well, and of course she could sense my frustration.
We crutched along like this for several short sessions, and I thought seriously about just asking someone else to come help, but when I sat down and thought about it, I was asking a lot of her. She hadn't done a lot of work with the gun and wasn't going to have that sort of innate feel of "that's about right," and here I was dropping her in deep water, leaving her to shoot while I grunted instructions through sheet aluminum. Throwing my hands up and kicking her out of the garage was hardly helpful.
Instead, I decided that we'd stop working on the fuselage and have a training session. After work yesterday, I grabbed some scraps lying around, drilled and dimples lots of holes, and clamped the pice in the vise, where she could shoot and watch the rivet head deform - aka the same way I learned. Having that instant feedback is obviously a huge help.
She did better, but still not great - lots of rivets were still overdriven, and we both ended up frustrated...again. Once again I started having those thought of giving up on her, and once again I instead starting thinking about ways to help her instead. I ended up realizing a couple of things. First of all, it was obvious that my method of controlling the rivet gun wasn't working for her. The way I control the gun is by putting my middle finger behind the trigger, like this:
I always thought of that middle finger as pushing back against the index for more control, but upon further thought, it was acting more like a limiter on how far I could squeeze the trigger. There was just a bit of travel before my finger started getting squeezed, which made for a natural limit. Knowing this, it was clearer why she was having trouble - her smaller fingers wouldn't be nearly as effective here. I started trying to think of ways to add a little bump stop behind the trigger, and then I realized the second, more basic problem: I was running too much pressure to the gun.
I do have a regulator on the gun, but I generally run it close to wide open. This isn't a problem for me; for one thing, I have my middle finger limit stop which lets me have fine control, and for another, I've shot thousands of rivets at this point. That is, I'm well-equipped to use the gun like this.
But her? I'm not sure I could have possibly given here a worse riveting setup. With less natural ability to limit the trigger, it only took the tiniest twitch to go past "just right" into "overdriving the rivet in a quarter-second." I might as well have taken a kid shooting for the first time and given him a micro Uzi on full auto.
So tonight, I went out and adjusted the pressure to the gun where it was impossible to run it in such a way that you could instantly ruin a rivet. Then I made up some more test pieces and let her shoot a bit more. Much better. Then I rolled up under the canoe and we shot row after row of beautiful rivets. Well, maybe not "row after row," as I was working in a tight spot and it was a bit tedious, but the important thing is that there were absolutely zero
Moral of the story: What works for you may not work at all for your helper, and it's on you to ensure you give them the tools they need. Your helper may not know enough to say "this thing is hard to use and I think it's wrong" - again, you as the experienced person have to lead the way here.