Left Fuel Tank Testing
Left fuel tank was thorougly tested, and leaks were fixed as they were discovered.
We finished testing, and sealing where leaks were found for the left side fuel tank. The process was tedious but got a lot of confidence in the end. The leaks were sealed using steel epoxy. The testing procedure was exact same as the right side fuel tank. In one of the photos, there will also be some rough math that was done to predict what the fuel loss might be in worst case scenario, which it came out to be less than a gallon per hour, which is not a problem, and can be accounted while flying.
Photos
Testing setup for the tank. 
Corner where minor leak was found and sealed. 
Corner where minor leak was found and sealed. 
Corners where leaks were found and sealed. 
Rough math behind potential fuel leak, takes into account fluid volume and pressure difference. 
Another corner where minor leak was found and sealed. 
Leaks were found in some rivet holes and sealed.