Sacrifice Gleaming Barrier to Krark-Clan Ironworks, adding ({C} magic symbol) ({C} magic symbol) and ({W} magic symbol) with the treasure token and putting a Thornbite Staff trigger onto the stack.
Holding priority, tap Goblin Welder, sacrificing Idol of Endurance and returning Gleaming Barrier to the battlefield.
Allow the Thornbite Staff trigger to resolve, untapping Goblin Welder.
Tap Goblin Welder, sacrificing Gleaming Barrier and returning Idol of Endurance to the battlefield, triggering Thornbite Staff to untap Goblin Welder and adding ({W} magic symbol) through the treasure generated.
Idol of Endurance ETBs and exiles Gleaming Barrier from your graveyard.
Tap Idol of Endurance and spend ({1} magic symbol) ({W} magic symbol) to allow yourself to cast Gleaming Barrier for free.