Well, I got back out to the garage this afternoon, but didn’t continue down my list, but I did do something I needed to figure out on the ER tanks.

Normally, the inboard (standard) tank gets screwed to the main spar, and along a join plate that’s attached to the outboard leading edge. Because I’m substituting another fuel tank, and it isn’t as long as the leading edge, there’s a gap between the two tanks. I want that gap for fuel and vent plumbing, but I’ll need to figure out how to close it out.

The inboard tank is easy. I’ll take the join plate normally attached to the leading edge and just screw it (permanently) into the inboard tank. No change to pre-punched holes, etc. The outboard side of that join plate already has prepuched holes that align with the inboard side of the leading edge, so I think I’ll cut a piece of skin from the leading edge that already lines up with that join plate.

For the ER tanks, I’ll take the join plate that would normally go on the outboard side and move it to the inboard side. I’ll use the nutplate and screw holes to allow for the gap skin to attach to, but I’ll have to trim down the join plate to make it fit “inside” the inboard side of the ER skins. Let’s get to the pictures…

So I took one of the join plates, marked a thin blue line at the min edge distance for the #40 attach holes, then marked and trimmed a cut line that would fit inside the inboard side of the outboard ER tank.

Here’s a trial fit of the right tank. This shows two join plates, oriented in the same direction. I’ve used the #40 holes to matchdrill the outboard ER tank, which will be riveted. The inboard tank (left side of the picture) will get #8 screws on the tank skin. I can’t decide if I’ll permanently rivet the cover (not shown) to the inboard join plate, or put a bunch of screws there, too. I’d rather have 2 rows of screws instead of 3, but we’ll see if it works.

Here’s how much I trimmed off the join plates.

Here’s the right two tanks.

Same pictures as before, just the other gap.

Now that I’ve sorted out the method, I put the tanks up on the garage shelves for safe-keeping.

Let’s get back to spar, rib, and skin prep.

1.5 hours, booked against the ER tanks.