A brazing spelter for small articles of brass consists of 5 parts copper, 3 parts zinc, and 2 parts silver, alloyed as explained on p. 63. If the seams are not required to stand much working after soldering, they may be joined edge to edge. When seams are formed in this way, little nicks, about 1/2 in. apart, should be filed out along the edges, so that the solder flowing through the nicks during the soldering operation will render the joint sound. If the seam is to be worked after soldering, a small lap is necessary to ensure adequate strength. To form seams of this type, first thin the edge of the metal along the end; that are to form the seams, about | in. in from the edge, so that when the two edges are lapped over each other the combined thickness at the seams will be the same as the single thickness of the metal at other parts. Cut a small cramp at the top and bottom of the seam, and fit the opposite edge in these tramps. After preparing the seams by either of the above methods, fasten binding wire round the articles so as to hold the seams securely in position.
Now powder some borax for use as a flux, and soak it in enough water to form a thick paste; place a little of this along the parts to be soldered, and gently heat the article by some suitable means, such as foot bellows and blowpipe, so that it will expand equally, and not disarrange the seam; increase-the temperature until the metal is a dull red, and then take a strip of the solder, dip the end in the borax, and, holding the opposite end with the pliers, rub the solder along the seam until a little melts off. Keep the solder in a molten state, and with a piece of wire flattened at one end gently rub the solder along the seam until every part is joined. Small articles of iron may be joined in a similar way with equal puts of copper and zinc, but if the iron is to be hammered much after soldering, 2 parts of copper and 1 part of zinc would be more suitable. With these solders mix equal parts of the borax paste and grains of solder, and along the seams place sufficient of the mixture to solder them when melted.
Some dry borax should also be kept ready at hand, so that a little may be taken and thrown on the solder at any point where the material does not appear to be flowing freely.