Alloying
I was making bronze, so I put 4 copper bars and 4 Tin bars in the smelter. The alloying itself worked fine, but those 4 bars of copper and4 bars of tin didn´t disappear so I was able to keep making bronze only from those 8 bars. I even tried to take the bars out of smeltery and put them back. The bug was still there
I am running on version 0.1.2t
I love this game and I hope I helped.