PATTERN MAKING 41 



For wood turners' and pattern makers' tools, the sharpening 

 qualities of the "Washita" are unsurpassed; but the quality differs 

 greatly in stones sold under this name, some being uneven in 

 hardness, and some soft and worthless. No trouble will be found, 

 however, if some good selected brand such as the one mentioned 

 above is chosen. A good size for an oil stone is 6 inches to 8 

 inches in length, and from 1| inches to 2 inches in width. The 

 thickness does not matter, but the stones usually vary from f inch 

 to 1^ inches in thickness. 



The oil slip should be about 4^ inches in length, and from If 

 inches to 2 inches in width, tapering from f inch on one edge to & 

 inch on the other, both edges being rounded as shown in Fig. 83. 



In using the oil stone, care should be taken to hold the level 

 of the tool flat, or nearly fiat, on the stone, so that the cutting 

 edge may be kept thin and in easy working condition. The stone 

 is held stationary on the work-bench, and the tool is moved for- 



Fig. &3. 



ward and backward over its face. In the use of the oil slip, on 

 the other hand, the tool is held stationary, with the cutting edge 

 or end up, and the slip is rubbed over the beveled surface with a 

 circular motion or stroke, until a keen, sharp edge has again been 

 imparted to it. An abundance of oil should always be used in 

 order that a finer and smoother edge may be given to the tool, and 

 the pores of the stone be kept clean and free from glazing. 



In the last few years an entirely new variety of oil stone and 

 oil slip has been placed on the market. It is called the India oil 

 stone, and is made from corundum, the hardest of all mineral sub- 

 stances except the diamond. These stones have wonderful cutting 

 qualities, and differ greatly from other oil stones in that they cut 

 steel much faster, impart better edges, and do not glaze. They 

 are also of uniform texture throughout. India oil stones are 

 furnished in three -grades coarse, medium, and fine and in all 



