I have no idea what this would do to an LP, but I use get some of those large 12" video laser-discs that would skip because the disc was too warped.
I would warm them ever so very slightly in the oven and then place them between two flat surfaces until they cooled.
Worked like a charm whether a wavy warp or dish-like.
You could experiment with a warped LP you don't care about to see if it will straighten the LP without ruining the grooves. I don't remember what temperature I used, but you must not melt the plastic even slightly. I'd guess 100 degrees Farenheit. Use a thermometer; don't trust the oven knob setting. Laser-discs were easier because it was just the clear plastic covering the metal disc inside with the digital information.
I would warm them ever so very slightly in the oven and then place them between two flat surfaces until they cooled.
Worked like a charm whether a wavy warp or dish-like.
You could experiment with a warped LP you don't care about to see if it will straighten the LP without ruining the grooves. I don't remember what temperature I used, but you must not melt the plastic even slightly. I'd guess 100 degrees Farenheit. Use a thermometer; don't trust the oven knob setting. Laser-discs were easier because it was just the clear plastic covering the metal disc inside with the digital information.