Today at work, stripping an OT engine, snapped of 5 small allen bolts holding a cover on, which were threaded into the water jacket, and that was after heating them first. Left about 1/4 inch stub proud of the block. Remembered something i think i read here, WAX So I heated them up pressed candle to them, grabbed on with the vise grips and out they came easy as pie. Next were some stuck galley plugs,thought I'd try it again, heated and applied wax, they practically fell out. I reccomend this highly to anyone. And to whoever mentioned the wax here in the first place, a big thanks.