After prosealing the right wing, I waited a few hours and then connected Van's fuel tank test fittings. Got 3/8" clear plastic hose for the setup with some blue food colering. Started the test around 9:00 pm on Saturday and checked on Sunday. The water level went down but it was due to turning the heat off in the garage. Temperature in garage around 8:00 am was 56 degrees with the water column about 9 inches below the original starting point. I did a quick check on coefficient of expansion and the temp difference was indeed about 9" difference. I marked the bottom level with a sharpie and will wait a few more days and let the tanks cycle between temperatures. As long as the water does not go below the bottom mark I should be ok. Also got a small paintbrush and make a soap solution to run over all of th seams and rivet lines. Because this is a quickbuild I really can't check the outboard seams unless I remove the tanks.
If all goes well over the next few days, I will consider the tanks leak free and move on to the right wing.
