I have a 1x12 x 32'' piece of fir or pine wood that was hand painted by sister - the wood is dried and warped slightly with a crack about 6'' long in center of board from one end to a knot in wood. I want to restore wood as possible to make a keep sake of it. the wood is painted with magic maker an water colors on one side. what is the best way to moisten wood to flatten an to be able to fix crack so as to apply a preserve finish and use as a wall hanging?