Belly Skin Clecoed

I spent a long time in the shop today. In fact it was such a long day that I was too tired in the evening to write up this entry and the only way I could get this in was to travel back in time and write this up the next day.
So, I riveted those forward corner skins in place that I hadn't prepared before I needed them. This NAPA 7220 primer is a really nice product for a rattle can primer. The green zinc phosphate stuff I had before from Tempo (A-702) was not worth the money or the effort to put it on. Even on scuffed surfaces (SB pad) it wouldn't stick enough for the primer to stay on during handling. Really useless stuff. So that's why I got the NAPA stuff a few days ago.


Anyway, the corner skins were a matter of minutes and then I had to work on the belly skin. I deburred holes and edges and broke the side edges for a slight inward bend.
Then I dimpled the nutplate attach holes and, guess what, put the nutplates in. There were 20 of them and it would have not so bad if that belly skin would be a bit more easy to handle. The thing is huge and getting that monster pneumatic squeezer (did I mention: heavy?) in the right position over a flimsy little AD3 rivet is a bit tricky when you have to handle a wobbly skin at the same time.


Well, with drilling out only one messed up rivet I finished this job as well and then threw the belly skin onto the fuselage structure. Wow! This thing looks and more and more serious now.
Clecoing the skin on was just a time effort as there are indeed a lot of holes. When putting the outside skin stiffeners on, I noticed that they were actually different pieces. When I cut them apart I didn't pay too much attention I guess as I hadn't noticed this before. I also primed them all on one side only (the side I intended to put on the belly skin) and I turned out to be 80% correct. 2 of the 10 pieces were pieces were primed on the wrong side. This is pretty good considering that I didn't even know they were different and that I had to go on in some specific orientation.


If you intend to prime these between the belly skin and the part itself, then I suggest you mark them when cutting them apart - preferably on the side you're not going to prime. That way you'll see the markings when putting them on.

And that was it. I'll start the riveting action that lies ahead next time getting to the shop.

One thing bothered me today though.
There was this option mentioned on the page but no details or explanation was given as to why someone would maybe like to go the optional route of adding 4 more nutplate around a mysterious hole that will later obviously get covered up. The nutplates might provide some access to this hole but without knowing what it will give access to later, it is almost impossible to make an educated decision. Does anybody know what this is for? Dave?


Not that I would like to rivet MORE nutplates but at least I'd like know what I'm missing out on...