Transmute Metal to Wood

You choose an area up to 400ft away that you can see. All metal objects up to a total of 100 lbs of weight are affected, within a 40-ft.-radius burst

Saving Throw none; Spell Resistance yes (object)

This spell enables you to change all metal objects within its area to wood. Weapons, armor, and other metal objects carried by creatures are affected as well. A magic weapon made of metal effectively has Spell Resistance equal to 20% per + of the weapon.

Miscellaneous non-plussed weapons or items are handled as follows:

A magic object made of metal effectively has Spell Resistance equal to 20% per magical type of rarity. See table below:

Artifacts cannot be transmuted. Weapons converted from metal to wood take a -2 penalty on attack and damage rolls. The armor bonus of any armor converted from metal to wood is reduced by -2. Weapons changed by this spell splinter and break on any natural attack roll of 1 or 2, and armor changed by this spell loses an additional -1 point of armor bonus every time it is struck with a natural attack roll of 19 or 20.

This effect lasts for 1 hour, Only limited wish, miracle, wish, or similar magic can restore a transmuted object to its metallic state, before the duration expires.