Shifts and expedients of camp life, travel & exploration

by William Barry Lord; Thomas Baines

It is rather curious that with brass the softening process is the very reverse of that we use with iron. Heat a bit of brass and plunge it into cold water, and, with a sharp knife or chisel, you may carve it almost like pewter; heat it again when finished, let it cool slowly, and it becomes as hard as before.

A traveller in Africa should be well provided with brass, the best form being that of stout wire as thick as stair carpet rods; this will serve for many useful purposes: hooks, rings, ramrods for guns, or almost anything can be made of it. While, in lengths sufficient to make armlets, it is always a convenient medium of barter, or payment for the services of the natives, who, though they will give nothing for hollow lacquered curtain rings, will always appreciate solid metal, that may be cut, worn away, or broken, and remains the same throughout.

Tinning Copper.

To tin copper: first clean the surface carefully by rubbing it with sandpaper or stone, or washing it with diluted nitric acid or aquafortis; heat it till it is rather too warm to handle, by placing a hot iron or pan of fire under the part to be tinned; rub on, with a feather, a little hydrochloric acid (commonly called spirits of salt) with zinc dissolved in it; then, with a soldering bolt previously rubbed on sal-ammoniac, touch the bit of tin you hold upon the copper, and, as you melt it, spread it evenly with a bit of rag over the surface you wish to tin; this ought to be done with the insides of all copper vessels that are to be used for containing liquids or for cooking, and also for the edges of sheets that are afterwards to be soldered together. Even if the edges were to be riveted, it would still be advisable to tin them, as they might then also be soldered by slightly heating them and running a little tin into the joint, by means of the heated bolt rubbed on sal-ammoniac, as before.

Small iron nails, tacks, fish-hooks, &c., are protected from the effects of rust by tinning. The process is carried out as follows:—First cleanse the objects to be operated on in diluted sulphuric acid, then place them with broken fragments of tin and sal-ammoniac in an earthenware bottle over a strong charcoal fire. When the coating of tin is found to be complete, they are first washed in clean water, and then dried in hot bran or sawdust.

Sheet metal, to join.

A very strong joint may be made by turning up, say ½in., more or less, of the edge of one sheet (Fig. 1), then laying in it the edge of the other (Fig. 2), and turning up the edges of both (Fig. 3); then, keeping the joint pressed down, lift up the second sheet as you would open a book, and press it out flat and open (Fig. 4). You cannot make this joint in the two edges of the same sheet, turned round upon each other (Fig. 5), unless you first nearly flatten the two parts (Fig. 6), when they may be doubled upon each other, and the sheet restored to its cylindrical form by the insertion of any pointed cylinder, such as, for instance, the horn of the anvil or a block of wood rounded and tapered at the end (Fig. 7). Suppose it is required to make a pannikin, this joint, whether previously tinned so that it may be soldered or not, is the only proper one, but the corners should previously have been cut away, so that only a single or, at most, a slightly overlapping double thickness may be left at top and bottom (Fig. 8). The bottom edge is now turned outwards by gently tapping it on the block or anvil edge with a hammer till it resembles a narrow flange (Fig. 9). A circular piece is now cut for the bottom so much larger as to allow a rim to be turned up all round (Fig. 10), and to admit the flange within it (Fig. 11); then setting it flat upon the anvil, and forcing into it a block of wood that has been cut perfectly to fit it, clinch down the rim of the bottom upon the flange (Fig. 12), and turn them both up against the side together (Fig. 13). The top edge may now be rolled over in the same manner, and it will give additional strength if the rim is strengthened by the insertion of a piece of wire. If the foregoing joints have been carefully made you will have a water-tight and, what is more, a fireproof pannikin with or without the aid of solder, and a handle can be riveted on or not just as suits your convenience. One great advantage of the folded joint is, that if it is not too tightly hammered down, the parts will slide freely on each other, and advantage may be taken of this for making an opening in one side of a cannister to be closed by a sliding lid; or, if you are making a pannikin or other vessel, and your metal is not large enough to make the whole circumference in one piece, cut a small strip (Fig. 14) of the breadth you wish the joint, say ³⁄₁₆in. or ¼in., and fold the edge of the metal twice over it (Fig. 15), then draw it out; do the same with the other edge, and also with the edges of the piece you intend to insert (Fig. 16), and you may then, with a little care, slip the parts together, and clinch down the joints as closely as you wish (Fig. 17). If the corners have previously been snipped off, or smoothed with a file, it will considerably increase the facility of doing this.

Utilisation of meat tin cases.