This quest is not available in game.
Find a vial of Alchemical Flame, a roll of Spellbound Insulation, and a Decommissioned Calefactor.
These items can only be obtained while the Dalaran Sewer Guards are off duty.
I can help you build your forge. I can even supply the metal for it. I do, however, require a few more... difficult-to-acquire components.
I need an alchemical heat source, some sort of insulator, and a calefactor. I'm certain that all of these can be found here in the Underbelly... if the guards are looking the other way.