Probably overkill but to prevent leaks I put down another bead of sealant to close any possible gaps and the backside of the rivets.
It’s 9 degrees Celsius in my workshop when I’m not working and around 15 degrees Celsius when I’m working on the plane. Although the low temperature the ProSeal isn’t sticky anymore after 2-3 days but isn’t fully cured yet.
To have good adhesion it’s better to add another layer of sealant when the first one isn’t cured yet.
I did both tanks, here a photo of rib 2 of the left tank:
