SOLDERING.
A piece of silver solder, a slate slab such as is ordinarily used for grinding ink, powdered or lump borax, and a soft hair brush of some sort are all that is necessary for the process of soldering in addition to what we already have.
The pieces of metal that are to be soldered must be absolutely free from all foreign matter. To insure this the joint is scraped bright with some sharpe-edged tool. Care must be taken to keep the fingers away from the joint as any moisture or greasy substance will prevent the solder from running. The best results are obtained only by being extremely careful as to cleanliness throughout the process. Being sure that the slab is perfectly clean, a little water is put in it and the lump of borax is ground around until the water becomes like thin cream. If powdered borax is used a block of wood will answer as a pestle to grind the borax to the right consistency.
The solder may be obtained any gauge, but about 20 answers for most purposes. After cutting the solder into pieces about 1/16 of an inch long and about the same width, drop them into the borax that has been ground to give them a coating of borax and to remove any grease that may have adhered to them. Coat the surfaces that are to be soldered with the borax being careful to get no more borax about than is necessary. Put the parts together and bind them with No. 24 iron wire, not too tightly. The pieces of solder are then lifted with the brush used for the borax or with a pair of tweezers and placed next to the edge that is to be soldered, about one inch apart. The object is then placed on the annealing tray, which answers for soldering as well, and with the blow-pipe it is heated, very slowly at first until the water has evaporated and the borax crystallized and dissolved, the flame may then be applied more directly and the object brought to a soldering heat. If the heat is applied too quickly, it will throw off the solder; and if heated hotter than necessary it is liable to melt or burn the parts being soldered, so the process demands the closest attention from the start.
The object is then pickled, washed in clear water and dried in the sawdust.
If the above directions are carefully followed good results may be expected.