interesting... I started anew and the shield at the alter is now.... Iron...? looking.. maybe steel...However.. My copper hammer cannot smack off the handles this time....
Does maybe "Initial spawn" start it as "just an object"
but then saving and reloading maybe turns it into a "Shield with no defined ingots, with a hand grip and wrist grip"? that it then automatically makes Copper because its undefined?... Cause honestly, I didn't really remember it being copper looking in the first place either, I only remember seeing the copper every other time I paid attention to it, which was after reloads...
Or has it been made that you need a hammer of quality or better to break down items, to allow for giving of "better items" than hammer, which would have to be turned away (can't be repaired/dismantled) or just "can't be dismantled into something that the player can exploit" (Note, the first part is a "this is kinda just introduced thing" for the event of possible repair in the future - not saying there's actual repairs in current version (which I do not know if there is or isn't, but I haven't seen it))
Is it also possible the heater shield is randomized?
Edit - Note: the shield pre-boss, pre-reload as it spawned immediately after a fresh start, not even 1 day of rest - Is non-physical, I can't smack myself at all, I can't walk on it, I can't pull it into myself, or anything. And I literally just started so I have no way yet of testing for "Post-boss"
edit 2- Reloading Converts the Iron-y looking Heater shield into a Copper, physical shield - Confirmed. I went off to get crystals and all the loots and stuff to bring back, had a save and reload in the meantime - and came back - I can now walk ontop of the shield, its rim is distinctly copper looking, not chrome/iron looking.
and I can. Indeed, Stand on it, and grab, and levitate into the air, like a magic carpet.
So I guess "shield with no physical/defined ingots" is quite likely to be the "fact" for that, and reload looks at it in the file and reads "No defined ingot? the fudge? Uhhh... I guess I'll just make it copper... "