378 



APPLIED SCIENCE 



the inside of the mold to the side of the flask, but this is not 



always necessary. The core, a body of sand baked hard, is then 



placed in its proper 

 position and fas- 

 tened by wire or 

 nails to keep it sta- 

 tionary. This core, 

 which is made in the 

 coreroom, forms the 

 inside of the finished 

 casting, and in some 

 cases is very frail and 

 must be handled 

 with care. Some 



FIG. 191. Pouring Pipe. After the mold has cores are of necessity 

 been rammed and dried and the core set, the ^^pin half a Hnrpn 

 next step is to pour the iron from the ladle m ade in halt a dozen 

 into the mold. parts and care must 



be taken to fit these 



parts properly. After the cope is replaced, and the two parts 



clamped together, the mold is ready for pouring. This is done 



either by hand- or crane-ladle, a bucket-shaped vessel of wrought 



iron lined with fine 



clay. 



Figures 188-192 



show various steps 



in the molding of 



cast iron pipes. 



421. Essen- 

 tials of Good 

 Molding. The 



first essential in 



the 



of 



6 S S ^ FIG. 192. Pulling Pipe from the Flask. When 

 molding is to se- the iron has cooled sufficiently, the completed 

 * , pipe is pulled from the flask. The pipe is 



tne proper placed on the skids where the core is cut out 



kind of sand for 

 the mold (Fig. 193). 



and the outside is cleaned. 



In selecting sand, the weight of the 



