MATERIALS FOR CONSTRUCTION 



J.HE appearance and the permanency of 

 camp stoves and fireplaces are increased 

 greatly if the materials for construction are 

 selected with proper care. The more impor- 

 tant materials include the following: 



A. Iron (for top grates, plates, doors, hinges, etc.)- 



B. Brick (lor lireboxes and flues). 



C. Concrete (for foundations). 



D. Stone (for masonry construction and dry stone con- 

 struction). 



E. Sand (for mixtures of concrete and for hearths). 



IRON AND BRICK 



Iron and brick have been discussed in fore- 

 going parts of this bulletin. 



BRICK 



See discussion under Fireboxes. 

 CONCRETE 



Concrete should seldom be considered except 

 for foundations. Mixtures for concrete are dis- 

 cussed under Foundations. 



STONE 



The natural cHmatic conditions may be in- 

 jurious to some kinds of stone, especially shales. 

 In locations where water will be used generally 

 to extinguish the fire, very careful considera- 

 tion should be given to the kinds of stone to be 

 selected for the proposed construction. In the 

 order of their resistance to heat the acceptable 

 kinds of stone are the following: 



A. Dense black lava rock. 



B. Fine grained sandstone. 



C. Coarse grained sandstone. 



D. Granite. 



E. Limestone. 



F. Laminated shale and river stone. 



Limestones and shales are most undesirable 

 because of the damaging effects of intense heat. 

 These stones have a large calcium carbonate 

 content. Granite will to some extent "flake", 

 and may crack. If the firebox is lined with 

 fire-clay brick, providing a means of protecting 

 these stones from intense heat or sudden 

 changes of extreme temperatures, any of the 

 stones in this list will be acceptable. 



Sandstones when procured with fine grain 



will withstand the heat in an excellent manner. 

 They are composed of fine sand which is held 

 together by some substances of a cementing 

 character, usually silica, alumina, or oxide of 

 lime. Those with the silica content are much 

 more desirable. 



Granite is formed by volcanic action and is 

 among the igneous rocks composed of quartz, 

 felspar and mica. Because of the quartz con- 

 tent this rock has good resistance to heat. On 

 the other hand, this type of stone is much more 

 difficult to cut than sandstone. 



Slate is not a heat resistant stone and is 

 subject to damage under high temperature. 



A Portland cement mortar, or a mortar of 

 similar qualities is desirable. The mix should 

 consist of one part cement, one part fire clay, 

 and five parts sand. A small amount of hy- 

 drated lime may be added to prevent the mor- 

 tar from setting too quickly. This, however, 

 should be used very sparingly and is not es- 

 sential. Mix thoroughly before adding water. 



There are two kinds of sand which may be 

 procured for mortar, as follows: 



A. Pit sand 



B. River or 1 



r bank sand, 

 ike sand. 



The difference between these two types of 

 sand is as follows: 



The river sand is generally free from any 

 clay content. The grains are less angular and 

 in general it is less desirable for use in mortar. 



Pit or bank sand usually has a small clay 

 or loam content which must be washed from it 

 in order to get the particles of sand clean. 

 The particles of sand are angular and some- 

 what rough and therefore make it much more 

 desirable for mortar making. 



Sand which is used for the hearth and also 

 for the area around the fireplace should have 

 a small proportion (approximately 10 to 15 per- 

 cent) of clay content, in order that there may 

 be some cementing quality in this mixture 

 otherwise the sand will not pack and become 

 firm under foot, especially around the fireplace. 



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