A neat trick known to most machine-shop men but not to many woodworkers, is to rub chalk on a file to keep it from filling up with the metal being filed. This knowledge is especially valuable in case of reducing a shaft by means of a file.
And speaking of chalk, it is good to use as an oil extractor for old belts. Rub the whiting into the belt as thoroughly as possible and then pack it closely in the same material and let stand for a day or two. The object of rubbing it in is to induce capillary action which will draw the oil from the saturated belt into the dry chalk. Of course all the oil will not come out but the belt will be dry enough for good service.- "Wood Craft. "