The next week, Kahn and Blackwall stood in Throk's forge room again. After the old dwarf ate his ear for the whole day during the first class… he and Blackwall were instructed by the old blacksmith to do their research first and were handed out over 30 massive books related to the blacksmithing craft.
And Throk warned them that he wouldn't start the practical sessions unless they memorized all the knowledge in them perfectly to the point where they could answer his questions even after he suddenly woke them from sleep.
But he estimated it would take over a month for both of his new disciples… took a lot shorter than he imagined.
As for Blackwall… the reason why he suddenly showed interest in Blacksmithing itself was because he was now a primordial titan and had a natural affinity with earth element as well as metal and minerals ever since Kahn merged him with the mountain titan.
Reference Art for Oakenshield company building in chapter comments. Check it out.