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More work on the fuel tanks

This post covers work done over the past 2 weeks.

Last weekend I devinyled the right fuel tank skin. I fired up my soldering iron and removed strips along the hole lines as usual.

I also removed the vinyl from the inside of the skin. I then clecoed the skins back into position. I ran out of #40 (silver) clecoes and only had enough to hold them loosely in position.

This weekend, I got around this shortage by removing some of the clecoes off the right wing so that I had enough to fit the left fuel tank skin into position. Getting this skin into position was a real challenge. Fortunately, my Uncle (Phil) came over to lend a hand and between the two of us, we managed to persuade the skin into position. We tried using some ratchet straps to pull the skin down but we couldn’t quite get anywhere using that method (as many other builders have done). We ended up getting the skin on by having one person hold the skin into position and push the leading edge down, whilst the other pulled the skin down with one hand so that a hole would line up and be able to put a cleco in. We started with the inboard rib and was able to progressively “walk the rivets” moving outboard for each successive rib. With the skin in position, I match drilled the holes in the tank skin support strap. We then unbolted the entire fuel tank assembly from the spar and placed it in the tank cradle. Phil took a photo of your truly standing next to my left fuel tank.

My mate Mitchell also came down to lend a hand so I was in the fortunately position to have 2 helpers. So I got Phil to start countersinking the fuel tank skin. The holes along the rear baffle plate needed to be countersunk. I set up the countersinking tool to the correct depth, did a few holes to show Phil how it’s done, then left him to do the rest. Here’s Phil in action.

With Phil set up, Mitch and I went to fix up a few loose ends that I had been meaning to get to for a while. The first thing we did was to make the eye-bolt screwdriver, thingy, whatchamacallit. I’ll call this tool, Mr T due to its shape, and because Mr T from the A Team is awesome. Mr T comprised of a few PVC piping parts glued together with some PVC cement. A notch is cut out of a section of conduit to the width of the fish-eye bolt. This tool is used to screw the eye bolts in without having to use a spanner, which is highly likely to damage the bolt due to it being a softer alloy. Here is a photo of the finished product.

Next we fixed up the Figure-8 hole that I made in the rear spar in the left wing. I bent a rivet over and when I drilled it out, I accidentally made a figure-8 hole. As always, the wondering people at the SABC helped me out and offered several ways to fix this. I decided to go with the “extra rivet” option. First, I marked a position half way between the two existing rivets (the figure-8 hole and the one next to it). I then drilled a #30 hole in this location and deburred the edges.

I then placed a new rivet in the new hole to do the job of the rivet where the figure-8 hole was. To fill in the hole, I put in a new rivet and roughly set it. It filled most of the figure-8 hole and is a funny s-shape due to the enlarged hole. I will probably put a small amount of filler in the figure-8 hole to make it more cosmetic during the finishing stage but for now it’s done.

I then picked out the angle I needed to fabricate the lead edge support brackets for the fuel tanks. I marked out the length of angle and cut to pieces to size. Using the drawings as a guide, I then marked out the shape of the brackets on the longer web.

I then used the band saw to roughly cut most of the metal away from the marked out shape. By this stage, Phil had finished up countersinking the holes on the fuel tank so we ended up calling it a day.

Build time – 6 hours


About gstrack

Husband and father of 2. Control & Instrumentation Engineer. Flying nut. Gadget geek.


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