Deburred left outboard skin. Next I edge finished the skin, using first a file and then some 350 grit sandpaper. Started on the scarf joint on the left inboard skin. Put duct tape under and all around the lower portion of the skin—didn’t want to put any file marks where they weren’t needed. Started filing the inboard skin-got interrupted by a sudden shower. When I started the test on the left tank, the temp in the shop was around 67 degrees. Well, today the shop tem got to 81+ degrees. Apparently, the higher temp pushed the water level down the tube, around the loop and back up the long side of tube. When the level pushed past the low point of the loop, the tank pressure could not sustain the column of water and it turned loose an air bubble. After the first bubble, it sorta hic-uped and water shot up the tube. Possibly vibration from filing on the skin contributed to the event. Not sure if additional testing is necessary—but will start the test again. So I refilled the tube and restarted testing.
