I have several Chinese jian, double edged straight swords, that I have acquired over the years, some of which were made in the 1970s and 1980s, when the Chinese companies were still making robust blades. These are thick and heavy, not flimsy wushu toy weapons. As such, they are heavy to the point of being unwieldy, and I am considering attempting to do some alterations. The blades are flattened diamond shape in profile, with a central spine, and no fuller. I am considering grinding them down on a belt sander, to flatten them and possibly make a fuller. I do not know what type of steel these are, nor if they are properly tempered. For the sake of discussion, let's assume they are of a "decent" quality and type of steel for a good blade, and the tempering is proper. If I do this, and cool it in water periodically, is it possible to succeed without destroying the temper? I am not in a position to have them retempered. Any thoughts on how I might go about this?