About 20 years ago my brother salvaged the wood from a pre-civil war farm house in rural north Georgia.
He saved one plank. Yesterday he told me that the plank which he thinks is pine and about 1/2 an inch thick was severely cupped and bent as a result of applying linseed oil to only one side. He would like to flatten the plank. His current thought is to apply linseed oil to the other side or try and use a solvent to remove the linseed oil (I told him that this would not work). I suggested either steambending it back or trying the old trick of laying it in the grass cupped side down on a sunny day.
What are his options for flattening what is probably and old growth plank that he would like to save...