Lotsa fitting and welding!
So many passes on that joint.
I wondered how they made the half-sphere.
some kind of fluid system.
The vanes were interesting,
either to straighten out the flow,
make them hum/whistle,
or to stop creatures from crawling through!
metal scrap trees.
I wouldn't be surprised if the artist gets paid more then the structural fabricator.
a strong zinc chromate primer typically used when more welding is needed.
A lot more detail with the paint vs powder coating.