CAMP STOVES AND FIREPLACES

THE appearance and the permanency of camp stoves and fireplaces are increased greatly if the materials for construction are selected with proper care. The more important materials include the following:

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

B. Brick (for fireboxes and flues).

C. Concrete (for foundations).

D. Stone (for masonry construction and dry stone construction).

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

IRON AND BRICK

Iron and brick have been discussed in foregoing parts of this bulletin.

BRICK

See discussion under Fireboxes.

CONCRETE

Concrete should seldom be considered except for foundations. Mixtures for concrete are discussed under Foundations.

STONE

The natural climatic conditions may be injurious to some kinds of stone, especially shales. In locations where water will be used generally to extinguish the fire, very careful consideration 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 content 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 hydrated lime may be added to prevent the mortar from setting too quickly. This, however, should be used very sparingly and is not essential. Mix thoroughly before adding water.

SAND

There are two kinds of sand which may be procured for mortar, as follows:

A. Pit sand or bank sand.

B. River or lake 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 somewhat 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.