Dunno about that...I like JB Weld for numerous repairs but would not trust flooding my house to it.
The halves are screwed together, so catastrophic failure just ain't gonna happen.
Assuming the metal is thoroughly cleaned/degreased before application, there's no reason the typically impossible-to-remove epoxy to steel bond would fail or leak.
Given that they market it for fuel tank repairs, I suspect they've done the risk analysis on their completed products liability.