With the fuel tanks complete, it's time to actually mount them on the wings. First though, I primed the outside of the rear baffle and the outboard end of the tank since they will be concealed when the tank is mounted.
I didn't realize it then, but the Pro Seal fillet along the edge of the rib was about to become a problem. I set the tank up on the wing and used some straps to provide some down force on the tank. I began to see that it wasn't going to line up along the inboard edge where is connects to the W-423 splice plate.
Fortunately my X-ray vision really helps out in situations like these and I was (eventually) able to figure out that it was the Pro Seal preventing a good fit. So the tank came back off of the wing for some Pro Seal surgery.
After I removed the fillet, I smoothed down the area with an Scotch-Brite pad on the angle grinder. Then re-prime and I'm back in business.
Now the the tank fits well against the outboard leading edge skin but the gap on the top skin is not as tight as the gap on the bottom skin. I tried to pull the tank skin down tighter with the straps, but it just wasn't having any of that... So I decided to forgo my Oshkosh Grand Champion builder's trophy on this plane and just let it be. There really isn't any discussion in the build manual on what the gap should be. I just assumed that the amount was zero. Luckily, the gap is a uniform 1/32" along the length of the tank and is not really likely to draw too much much derision from my fellow builders. I just can't understand why the gap had to be on the top of the wing and not the bottom.
Once the periphery of the tank is screwed down, the AN3 bolts that attach to the back of the tank via the Z brackets are applied. This is where I thought the real difficulty would occur. The bolts have to mate with the nutplates on the Z brackets through holes drilled through the main spar web. The slightest misalignment could prevent the bolt from threading into the Z bracket. Here are the AN3 bolts and torque wrench ready for action.
The view inside the wing. Getting ready to tighten these three down. There are a total of 21 bolts for each tank. To my surprise and great delight, all of the bolts in both wings slid right in. It seems oddly unlikely and somehow inappropriate; Like I was using someone else's luck. I'm used to things being far more difficult than I expect and this just seemed wrong.
And that is it for the tank attach. Up next, landing and taxing light install.
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