Put one of the warped junkers in a 225 degree oven on a cookie sheet. Dab with a wet paper towell (so you won't burn your fingers) every 20 seconds or so until it flattens out. Remove cookie sheet & let chip air harden on top of stove or counter. You will be able to get the warp out before the clay begins to melt or destroy the chip. Do it slowly. Don't try this with an expensive chip until you become experienced with the amount of time to let it heat up.