A couple of days ago I leak tested the right fuel tank. Everything looked good except for one small area at the outboard top corner where the baffle and outboard rib meet. These corners are notorious for having leaks because of how they have to be put together (put a huge blob of proseal sticking up in the corner and hope it smooshes down just right in all of the right places when the baffle is pressed down - there are actual gaps it has to fill, whereas in all other areas it's sealing two tight surfaces together).
Luckily, this area is right inside where the fuel cap filler flange is, so access was easy. I pulled out my borescope and stuck it in so I could see what the proseal looked like in the corner. As expected, it was kind of a mess. It's super thick because I put a big blob there, but apparently there were still gaps somewhere. To fix it, I just used a gloved finger and spread a bunch more proseal over the corner and along the edges. It's a lot of sealant, but after leak testing again (a few days later - I'm late updating) it seems to have done the trick. No more leaks. If I remember to, I may do one more leak test on each tank just before I install them on the wings for good.
