Originally Posted by
Morphic tide
Arcane Spell Failure only applies to spells with Somatic components, and is the only constraint affected by Armored Mage. Heavy shields prevent you from using that hand for material or somatic components independently of ASF. Arcane Channeling requires a weapon to deliver the attack. Consequently, the only conditions where the Duskblade's 7th-level improvement of Armored Mage applies to their Arcane Channeling is if they are doing it with a Shield Bash, an Unarmed Strike, a book-dived probably-Exotic hands-free weapon, or have more than two arms.