Sacrifice Gleaming Barrier to Krark-Clan Ironworks, generating ({C} magic symbol) ({C} magic symbol) and ({W} magic symbol) from the treasure.
Activate Golbin Welder by tapping it, sacrificing Idol of Endurance and returning Gleaming Barrier from the graveyard to the battlefield and triggering Intruder Alarm, untapping Goblin Welder and leaving ({2} magic symbol) ({W} magic symbol) floating.
Activate Golbin Welder, sacrificing Gleaming Barrier and returning Idol of Endurance to play, exiling Gleaming Barrier to Idol of Endurance's trigger and adding ({W} magic symbol) through the treasure, leaving ({2} magic symbol) ({W} magic symbol) ({W} magic symbol) floating.
Activate Idol of Endurance for ({1} magic symbol) ({W} magic symbol) and cast Gleaming Barrier without paying its mana cost, triggering Intruder Alarm and untapping Goblin Welder, leaving ({1} magic symbol) ({W} magic symbol) floating.