I finished sealing the tanks about a week ago, and the last two days I spent leak testing them. I made a water manometer and pressurized the tank to about 20″ of water. Over the course of 4 hours the tank pressure fluctuated a little, as the temperature rose in the garage the pressure went up slightly. I didn’t bother doing the math to calculate the pressure rise, but it’s safe to say if there was a leak it wouldn’t go up. Just to be safe I also sprayed the whole tank with soapy water to see if bubbles formed. This actually cooled the tank down a bit as the cold water was sprayed on, and the pressure dropped down. 

This is the setup I did for both tanks. And both are rock solid. A big milestone under my belt and I’m glad it’s over! I performed a similar test for the other tank and let it sit overnight. Again no drop in pressure and no bubbles formed at any point on the tank. 

I then spent some time installing the tanks onto the wings, once they are installed there’s only a couple more things to do to mark the wings done. 

1. Install right aileron and brackets. 
2. Install wiring conduit in right wing
3. Debur and install bottom skins
4. Wing tips

3 and 4 will be pushed off until the very end of the build. There’s no rush in installing the bottom skins as it’s better to have access than to not. 1 and 2 should be a few hours work and then I’m done! Wings will be put into storage and then fuselage time.