Totally agree prd. And I have welded tanks with ACE/Ox torches. Even the unburnt gases from the torch can build up in the tanks and become an explosion hazard as they do ignite later. Enclosed spaces always invites this hazard. An empty tank can be a lot more explosive than a full tank. This is why those of us that cut things like propane tanks fill them with water to limit the hazard but they do great BBQ grills once we safety open them up.
As NormK said the tank must be cleaned properly plus I would add well vented or water filled to do repairs. Even those tanks with the foam type baffles can still be very dangerous.
Sorry, but we all need to use our heads and stay safe. With things like this, we just don't need to take chances with.
