How is this metal sign made?

[bannertime]

Oh wow, that's sad. I'll still stick with my guess. It's not like folks stopped porcelanization, it was more of a cost vs performance issue. In any case, if it is porcelainized, you can bend the panel, and the surface should shatter and pretty much fly everywhere.

Lol, I'm strong, but I can't bend a 1/4in aluminum panel fastened to another 3/8in aluminum panel. I can chip away at the coatings. There does appear to be a primer layer. Not sure if that was used in that process or not.

 

[Billct2]

I also thought it could be porcelain. There was a company near me that was doing them till fairly recently. But the paint/mask/paint/clear is probably the most economical way to duplicate it