I will second that.
Many years ago my dad thought he was being clever by making the boiler lagging sheets for our Aveling & Porter steam roller from zinc coated sheet, he assumed it would last longer in that environment and it probably would have done.
Etch primer was not very common back then, and the nice new shiny black coach paint and pin striping all started peeling of within a few weeks !!
When we restored the Fowler road loco, we used blued steel sheet for lagging the cylinder block, that looked superb.
Phil