Talk to 'Villager' Behind 'Andria' the Blacksmith in Keplan.

I got the quest at level 9 in gathering and level 8 in processing.

J'ai obtenu la quête alors que j'étais Professionnel 9 en récolte et Professionnel 8 en transformation.

First go to your black spirit and select guide. Make sure that you have completed all the beginner shaking,grinding,etc. After you've done that get Pro 5 processing and Skilled 10 gathering. Only than can you even start the quest chain from the villager (which is behind the blacksmith in the room). After you can meet vatudun and eventually get the quest. Also i reccomend bringing 10 coal, 15 melted iron shard, and 2 metal solvent so you have everything to finish the quest right there.

You can also heat certain pieces of gear for a chance of obtaining a pure iron crystal. In-game crafting notes gives a list of items that you can melt.