PATTERN MAKING 



137 



in such a way that the main body of the pattern can be lifted out 

 without disturbing them, and they are then withdrawn from the 

 sand through the cavity left by the main pattern. 



Cores for Columns. Cores for columns may be made in core 

 boxes as in the case of those for pipe, but where the core is 

 long and straight no core box is needed. The core is usually 

 built of loam about an iron pipe as explained in Foundry Work. 

 Where the core is to follow the lines of the ornamental 

 mouldings on the outside of the column, it may be provided with a 



special core box or better with a 

 sweep as shown in Fig. 252. This 

 sweep is used to shape the loam 

 core that is to be built up on an 

 iron pipe. Fig. 252 is the out- 

 line of the template that is to be 

 used in sweeping the core for the 

 interior of the columns shown 

 in Fig. 253. 



Follow Boards. All thin 

 patterns that are likely to suffer 

 distortion from the pressure of 

 the sand while being rammed up, 

 must be provided with accurately 

 fitting follow boards. These fol- 

 low boards may be made to fit 

 on either one or other of the 

 sides of the pattern. 

 Pig. 252. Fig. 253. When the Ollt lines of the 



pattern are very irregular, the follow boards are often made of 

 plaster or other composition, which, when dry, is used to support 

 the pattern while the drag is being rammed. 



Fig. 254. 



Fig. 254 represents a section of a railing cap. If the pattern 

 B were to be set with the edges a a resting upon the moulding 



