Through research, I understand that Vulcan is the god of Forging, but deeper research and eldrich wizardy has led me to realize that the god of Smelting is, in fact Cthulu.
I came to this realization after a smelting session when, totally unbidden, I found an Idol of/to Cthulu under my smelting pot...
While this disturbed me greatly, as the necronomicon had convinced me that Cthulu and the rest of the Elder gods were, in fact, evil, my discovery led me to the devine benefits of Angle Iron Ingots....
Using my 2# angle iron ingots, I will be able to stack over 1000# in the same space as 800# of Lyman Ingots...
So... be aware that Cthulu is watching you as you smelt... and remember to sacrifice a Statist/criminal to him whenever you get the chance...