PATTERN MAKING 



required shapes, a few of which are shown in Fig. 84. Only the 

 "fine" stones are adapted for woodworking tools arid for those 

 classes of tools requiring a fine cutting edge. 



GRINDSTONES. 



Second in importance to a good oil stone is the grindstone, 

 power-driven if possible. It should not be too close-grained. A 

 rapid-cutting stone, even if moderately coarse, is greatly to be 

 preferred, as all ground edges must be finished on the oil stone 

 however finely they may have been ground on the grindstone. 



A stone about 36 inches in diameter when new, is a good size; 

 and can be bought with a suitable cast- 

 iron trough underneath, and also with 

 an arrangement for supplying the water 

 necessary to keep the stone wet. 



In all stones there will be found 

 great differences of hardness in different 

 parts. Stones soon lose their cylindrical 

 shape and must be turned true. A piece 



^ g as -piP e or an ld fil e wiM be found 

 excellent tools for this purpose, but they 

 must be used without water. 



In using the grindstone for plane- 

 irons, chisels, and other tools that must 

 be ground with a long bevel, or to a thin 

 edge, it is better to stand so that the 

 stone runs toward the cutting edge of 

 Fif,'. 84. the tool, as shown in Fig. 85. This 



position grinds the tool much faster, and less of a feather will be 

 turned up on the final edge. 



Scraping tools, however, and indeed all tools having a very 

 short bevel, or whose edges are ground to a very obtuse angle, may 

 he held so that the stone will revolve away from the cutting edge 

 of the tool, this position being less liable to cut hollows in the 

 face of the stone. This method of grinding, however, is too slow 

 for tools having a long bevel, and which for that reason require 

 more grinding. 



