Every day, the blacksmith can dismantle up to five items into metal and arcane splinters.
If an item is dismantled, it is irretrievably destroyed! However, you get back a proportion of the resources used if this item was previously upgraded by the blacksmith. This does not apply to e.g. weapons that have been in the toilet as they lose their sales value there.
Scout and mage weapons give you more resources when dismantled, but consume two of the five blacksmith points. To dismantle an item, drag it onto the appropriate area at the blacksmith or use the right-click context menu on the item to be dismantled. The item you want to dismantle must be in the backpack.