Tom Del Rosso wrote:

Pete C. wrote:

- Inspect carefully for cracks

Everyone agrees on that, but how? If it was the hull of a sub or a reactor
vessel they would use xrays. There must be a good reason for that, so
something more than a magnifying glass might be advisable. Maybe some
chemical would make a crack more visible under a UV light?

Good 'ol Magna-flux would work, but I think just cleaning the paint in
the area and inspecting with a magnifying glass and good lighting would
do. Combined with a visual inspection inside the tank via the 2" side
port that should give reasonable confidence that it really is just one
porous spot in the weld.