44 



MOULDS FOR BOAT-LEADS. 



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Here are three illustrations of the mould for boat- shaped leads 

 in wood; first, the mould screwed together (fig. 8); second, half 



the mould showing 

 the position of the 

 brass wire (fig. 9); 

 third, a cross section, 

 showing the form of 

 the cavity (fig. 10). 



The moulds may 

 be made of wood, as 



FIG. s.-Mouid for Boat-shaped Leads. follows : take a piece 



of fir or deal, three 



inches square and a foot long, saw it through the middle, and 

 with a spokeshave take out of the inner edges half the dimen- 



FIG. 9. Longitudinal Section with brass wire. 



sions for the lead, and screw the two pieces tightly together. 

 If of freestone, rule a straight line on it, and, marking the 

 shape of the lead, scoop out the mould 

 with a knife and gouge, or get a stone- 

 mason to prepare it for you. 



You may cast twenty to thirty leads 

 in the wooden mould, but that of free- 

 stone will never wear out, although it 

 may break through the heat of the 

 molten metal, to prevent which fill it 

 with hot ashes previously. The charr- 

 ing of wood moulds may be hindered 

 by oiling them, but when they begin to 

 burn they should be lined with thin 



FIG. 10. Cross Section, 

 showing form of cavity. 



sheet iron, which when first put on should be painted with 



