I never realized that the 123 tanks where fabricated from uncoated steel. It seemed that Honda four wheeler tanks would so easily rust through from the inside years ago. I suspected almost no protective coating.


Early gas tanks seemed to be fabricated from hot dipped metal being applied. Then possibly electroplated coatings where used. Tern steel was the common term for the sheet steel gas tanks where made from.


I ran across GMs internal cost to make a fuel tank years ago. Possibly in the 1980s. It was about eight dollars in total. This would not include the gauge I imagine.


On a really old gas tank. Sometimes dried gas residue can resemble rust.