I

Fine silver, 2 parts; bronze, 1 part.

II

Silver, 68 parts; copper, 24 parts; zinc, 17 parts.

Solder for Silver Chains

I

Fine silver, 74 parts; copper, 24 parts; orpiment, 2 parts.

II

Fine silver, 40 parts; orpiment, 20 parts; copper, 40 parts.

Soft Silver Solders

See also Brass Solders, Copper Solders, Gold Solders.

I

Fifty parts bismuth, 25 parts tin, and 25 parts lead. This mixture melts at 392° F.

II

Fifty parts bismuth, 30 parts lead, and 20 parts tin. This will melt at 374° F.

III

The solder that is used in soldering Britannia metal and block tin pipes is composed of 2 parts tin and 1 part lead. This melts in the blow-pipe flame at many degrees lower temperature than either tin or Britannia metal, and it is nearly of the same color. Care must be taken in mixing these solders to keep them well stirred when pouring into molds. Care should also be taken that the metal which melts at a higher temperature be melted first and then allowed to cool to the melting temperature of the next metal to be added, and so on. Articles to be soldered with these solders should be joined with a blow pipe to get the best results, but if a copper is used it must be drawn out to a long, thin point. For a flux use powdered rosin or sweet oil.

Tin solders for soldering lead, zinc, tin, tin-plate, also copper and brass when special strength is not required, are prepared as follows:

I

Tin, 10 parts; lead, 4 parts; melting point, 356° F.

II

Tin, 10 parts; lead, 5 parts; melting point, 365° F.

III

Tin, 10 parts; lead, 6 parts; melting point, 374° F.

IV

Tin, 10 parts; lead, 10 parts; melting point, 392° F.

V

Tin, 10 parts; lead, 15 parts; melting point, 432° F.

VI

Tin, 10 parts; lead, 20 parts; melting point, 464° F.

The last of the above mixtures is the cheapest, on account of the large quantity of lead.

Bismuth solder or pewterer's solder fusible at a low temperature is prepared by melting together:

I

Tin, 2 parts; lead, 1 part; bismuth, 1 part; melting point, 266° F.

II

Tin, 3 parts; lead, 4 parts; bismuth, 2 parts; melting point, 297° F.

III

Tin, 2 parts; lead, 2 parts; bismuth, 1 part; melting point, 320° F.