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ENAMELING ON SILVER AND GOLD

Silver

A great deal depends on the thickness of the metal and its condition. Quite often a piece of silver has considerable temper in it. This is sometimes called "Fire." These pieces are usually annealed two or three times to "draw the fire," or the temper. Annealing is done by heating the piece to about 1200° F. and allowing to cool to room temperature. The process is repeated at least once and sometimes twice. Silver is a harder metal than copper and when made into shapes tends to move, or warp, in the enameling process more than does copper. Consequently one must be careful about the forming of the metal and the lines or design of the article to be made. For instance, sharp corners on boxes are troublesome.

Silver to be satisfactory for enameling should be white and shiny. This is especially important when transparent enamels are used. After annealing, one can use the acid cleaning as suggested in the text on page 14. He can also dip a stiff bristled brush, such as a tooth brush, in water and then in baking soda and brush vigorously until a satisfactory surface is obtained.

Enamels that are used on copper are also suitable for silver. The usual exceptions are most transparent reds and purples and fluxes or glazes. In these instances, the piece is enameled first with a special flux or glaze for silver. This gives a brilliant white background. Then the reds-purples – decorations, etc. are applied on the flux which acts as an underglaze. Flux or glaze is also used as an overglaze to protect painting, or decorations and also give the appearance of depth. This procedure is often used in making of vanity cases, jewel boxes, etc.

Silver electro plate and silver rolled plate or silver filled pieces are not usually annealed because the base metal is copper, iron, steel, or stainless steel. The less heating of plated pieces the better. Not all rolled plate or silver place pieces are suitable for enameling. Care should be taken to specify pieces suitable for hard or porcelain enameling.

Kiln firing of silver and silver plate is usually done at about 1300° F. The time in the kiln depends upon the size and thickness of the piece, type of planch used, etc. If several firings are to be made, it is advisable to under-fire the first coat. That is, the enamel is not fired to a smooth finish, but rather to a slightly wavy surface. This coat will smooth out in later firings.

Torch firing is the same for all metals. See page 28 in text.