Riveting the Trap Door

Here is a pic of the lower hinge assembly with the trap door riveted in place. I used my manual rivet squeezer for all the rivets due to the slippery nature of the hinge metal and the tight quarters that the squeezer needed to fit into, requiring a bit more control than if using the pneumatic squeezer.

The rivet on the left was the first one that was set, and of course, this being the first rivet I have set in quite a while, it naturally got messed up and I had to drill it out an reset another one. In the process of that the ends of the door next to that rivet bowed a little bit, and so even the replaced rivet is not very well set. Thoroughly aggravated by this, I decided to leave it alone before I caused any more damage to everything.Here is a blurry view of the bottom side. this actually turned out OK.

And here are the flush sets that I used in the hand squeezer with a standard 3 inch Yoke:

I used the larger 1/2 inch wide by 1/8 inch thick flat set against the manufactured head of all rivets, and the smaller 3/8 inch wide by 1/2 inch high flat set for all shop heads. I did it this way to ensure that the set would not accidentally end up hitting the hing rings, deforming them so that the pin would not rotate freely. This worked OK except for that very first rivet.

For the top hinge rivets, I was able to set the first one relatively easily, but the second one required the use of my bench vise, and a spare piece of wood that would fit inside the the flat part of the rib web surrounded by the stiffener ring on the outside. I need both hands to ensure that the rivet sets would be positioned properly and not screw something up - like smashing the stiffener ring, thus ruining the entire rib and forcing me to start over.
While I did not get a pic of it clamped to the vise, here are the pieces that were positioned onto it. The vise was lightly clamped, just enough to secure the rib so that I could position the squeezer and set the rivet.

Here are the shop heads - you can see how close the one is to the edge of the stiffener ring to get an idea of just how tricky it was to position the squeezer to set the rivet.

And here is the other side with everything riveted together:

Now, can you see my next dilemma? I still have to decide how to "secure" the other side of the hinge. This turned into yet another head scratching moment, and caused me to wonder of I should have trimmed and bent the other side of the hinge pin before I riveted everything in place. Unfortunately, I did not do that. Now I have to figure out how to accurately bend this pin with everything now tightly secured to the rib web.

This revelation led to yet another interesting observation. It involves a decision about how tightly or loosely to leave the other side of the previously bent hinge pin, and the same question for the bend to the pin on the other side. too much lay will allow the pin to slide from side to side a certain amount, and over time this would run against the rib web and/or the proseal in a very critical area of the tank that is very prone to fuel leaks as a result of it not getting sealed enough in the corner between the rear rib flange and the other rib flanges. It could even start scratching against the rib web, and I have already seen some evidence of this.

But none of these things was as disturbing to me as what I discovered while checking for freedom of movement of the door. Sometimes the door would not open when the rib was in a position where the gravity should have caused the door to open easily. A closer inspection revealed that this would happen when the 90 degree bend in the hinge pin would get forced very close to the first hinge rung that it encounters. This was effectively locking the door in place, not allowing it to open, similar to this next pic - and this is NOT good.

A closer inspection of the pin revealed why this is happening:
The pin is not bent at a perfect 90 degree angle. There is a slight amount of bend on the pin just prior to where it actually bends 90 degrees, and this bend is slight enough to allow it to be inserted into that first hinge rung if that end of the pin has any force exerted on it.I think I can try to straighten it a bit where it won't be as much of an issue, but the problem is you are just trading one bend for another one - that one being the 90 degree bend in the pin. Now matter how hard you try, there will still be a potential situation where that end of the pin with the bend in it can cause friction when forced up against the rung in the hinge.

So right now I have mixed feelings about this, and they consist of everything from abandoning the entire flop tube assembly to doing the "best I can" with the hinge pin and not worrying about it too much. Whatever I decide to do, I just do not want to ever run out of fuel for any reason unless I intentionally want to drain  tank completely for some reason.

I could not get the pic to focus properly, but you can still see the small bend in the straight part of the pin just before it gets to the 90 degree bend. I have some small hobby pliers that I think I can use to remove that small bend on that side of the bend and complete the bend on the other side as well.

What a pain - and look how much this has time sucked the build - all for a little door in a rib - crazy.