Set up to pressure test the right wing. You do not use much pressure, actually about 1 psi. After sealing the fuel tank filler port, I put a ballon on the tank vent and a filler port in the fuel tank drain. The first ballon I used tore, the second had a leak, finally the third one worked. I pressurized the tank using a bicycle pump. I stopped pumping when the ballon started to inflate. When I left the hangar at 2:30 the ballon was still inflated. I believe I have a sealed tank.