Tank Leak Testing

Time: 3 Hours

I had planned to start the leak testing yesterday but got a late start on that task in the afternoon when I found a big flaw in my plans. I started by attaching the sump drains after getting some FuelLune from a fellow builder, thanks Glen!

When I finally got those installed I ran out to the airport where we keep our Lear 45 to grab 20gal of 100LL to do the testing. I was real excited to get this under way and ran home to fill one tank. Simple enough right! I set up the fuel can higher than the wing, placed the siphon hose in the can/wing and pumped away. So what could be wrong you ask? Well I make some dumb mistakes sometime, and this was one of them. If you remember that I placed the flop tube and fuel vent lines on the inboard rib. Well I forgot to get any caps to cover those open fittings to keep the fuel in the tanks! So after a gallon or so I started to hear fuel dripping! I was glad to see it was the fuel lines and not a bad rivet. So I stopped the fueling and got on the laptop and ordered 4 caps and some other supplies I needed. What a bonehead move on my part! Oh well live and learn! After breakfast today my fellow builder Glen bailed me out again with a -6 cap that I could use for the flop tube line and he said to use a plastic hose and clamp for the -4 vent line.

I used my safety wire and pliers to secure the hose to the fitting and folded the hose 3 times with a clamp to close the open end. With the lines now securely closed I commenced filling again.

I only have two 5 gallon fuel cans so I had to run back out to the airport to get the last 10 gallons. When I got home I emptied those into the tank to make the 20 gallons. After I got all 20 gallons in the tank I found that the hose I had used in the vent line wouldn’t seal tightly to the vent elbow so it was leaking just a little. To prevent this I had to lay the tank flat and remove the clamp from the hose so that the fuel coming from the vent could drain and would have any pressure causing it to leak at the tube/elbow joint.

So I will let it sit in this position for a few days then flip it over for the same. Hopefully no leaks, all fingers and toes crossed!

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