Improved Soldering' Acid

A very satisfactory soldering acid may be made by the use of the ordinary soldering acid for the base and introducing a certain proportion of chloride of tin and sal-ammoniac. This gives an acid which is far superior to the old form. To make one gallon of this soldering fluid, take three quarts of common muriatic acid and dissolve as much zinc as possible in it. This, as is well known, is the common form of acid used in soldering. Next dissolve 6 ounces of sal-ammoniac in a pint of warm water. In another pint dissolve 4 ounces of chloride of tin. The three solutions should then be mixed together. After mixing, the solution may appear cloudy, and can be cleared up by a few drops of muriatic acid, care being taken not to add too much. The acid is used in the same manner as any ordinary soldering fluid. It will be found that it will not spatter when the hot iron is applied, and also that a cheaper grade of solder may be used with it, if necessary.

Urbana, Ill. T. E. O'Donnell.

How To Solder Aluminum

The great disadvantage of aluminum to the sheet metal worker is the difficulty encountered in soldering. This is caused by the formation of an oxide on the surface of the heated metal, the oxide preventing the solder from alloying with the aluminum. This difficulty can be surmounted by employing the following method:

Make a solder of 80 per cent tin and 20 per cent zinc, and use stearic acid as a flux. Tin the surface with the above, moving the copper bit backward and forward over the metal and flowing the solder. The film of oxide can then be cleaned off, and the coated surface can be easily soldered with the above-named solder or ordinary tinsmiths' solder. A. Eyles.

Manchester, Eng.

Gold Solders

Gold solder suitable for 18-karat work: Gold, line, 1 ounce; silver, fine, 144 grains; copper wire, 06 grams. (Troy weight. )

Suitable for 16-karat work: Fine gold. 1 ounce; fine silver, 144 grains; copper wire, 168 grains.

Suitable for 15-karat work: Fine gold. 1 ounce; fine silver, 240 grains; copper wire, 240 grains.

Suitable for 14-karat work: Fine gold, 1 ounce. fine silver, 300 grains; copper wire, 300 grains.

Hardest silver solder: Fine silver, 1 ounce; shot copper, 120 grains.

Best hard silver solder: Fine silver, 1 ounce; shot copper, 105 grains; spelter, 15 grains.

Medium silver solder: Fine silver, 360 grains; shot copper, 96 grains; spelter, 24 grains.

Easy silver solder: Fine silver, 336 grains; shot copper, 108 grains; spelter, 36 grains. H. D. Schattle.

Syracuse, N. Y.

Soldering Paste

By the requirements of the electrical trade, in certain cases no acid soldering flux can be used. A flux that can be used on any kind of work is known as a soldering paste. For soldering copper wires and other electrical conductors the paste is un-equaled, and is particularly adapted for work in which spattering and corrosion are objectionable. The mixture for soldering paste consists of certain proportions of grease and chloride of zinc. The grease commonly used is petrolatum or vaseline, which will give the paste the proper consistency. The proportions used are petrolatum or vaseline, 1 pound, and 1 fluid ounce saturated solution chloride of zinc.

Urbana, Ill. T. E. O'Donnell.