PNW Sling: Wing Tank Installation

My wings and fuel tanks were assembled at the Sling factory in Johannesburg and shipped over with the fuselage as a quick build. The tanks were clecoed in place during shipping and the factory still recommends that the they are leak checked again before riveting them to the wing spar.

The wing tank fitment to the wings is very tight and it takes two people to safely remove them.

With the tanks off, I used a pressure regulator to supply 1bar of continuous pressure to the tanks and sprayed soapy water on all over the tanks.

Slings recommendation to check the tanks again turned out to be sound advice, and a leak was found within a few minutes of spraying the first tank.

Fortunately this was the only leak that was found on both tanks and I could move on to repairing the leaky rivet.

The repair consisted of the following

1. Drilling out the old rivet

2. Cleaning out the metal shavings which actually wasn't too bad considering it was so close to the sender side of the tank.

3. A new rivet was installed with a generous amount of pro-seal, and allowing it to cure overnight.

4. The leaky tank was re-tested the following day and no leaks were detected.

The tanks were now ready to be installed and were clecoed into position. The tanks das I mentioned fit very tight to the wing spar and it took a while to align the holes in the skins to the holes on the spar.

Even with the holes aligned, match drilling is required to seat all of the rivets into place.

Match drilling at this stage is very dangerous as it is super easy to drill through the wing skin and into the tanks causing them to leak.

I used a drill stop (tape) to ensure that I did not f#uck up and drill holes in my tanks.

Tip #1

There are several builders that have drilled holes in their tanks so use some type of drill stop and save yourself the pain and suffering of a repair.

Another view of the bottom of one of the wings