This cleaning fluid may not be of much use in the shop, but if some machinist should get the machine shop grime on his "Sunday-go-to-meeting" trousers, he will find it useful for cleaning out the spots; it works like magic: Sulphuric ether, three drams; alcohol, six drams; chloroform, three drams; gasoline, one quart. The mixture can be used safely for cleaning the most delicate fabrics, but being highly inflammable, it must be used with caution around fires and open lights. M. E. Canek.
Tripoli, emery cake and crocus are all made in practically the same manner, the change being made in the composition when it is desired to have the composition more greasy. Melt tallow and paraffine wax or beeswax together. Beeswax is by far the best, but the cost of the same has led to the use of paraffine, which in many cases will work equally as well. After the tallow and wax are thoroughly melted, add tripoli or emery, whichever is to be made, a little at a time and stir in well until it is as thick as is possible to make it; then pour out into a large tin, or better still, into the molds made for the purpose, and allow to cool. J. L. Lucas.
Mixing lampblack and shellac is not so simple a matter as it appears, as many an amateur and novice has found out. The tendency is to form lumps, when the two are mixed by throwing or even sifting the former into the latter. The lumps of course can be reduced and an intimate mixture obtained by considerable patience with a paddle or pestle. The whole difficulty is easily avoided if the lampblack is first wet with alcohol and throughly worked down into a soft paste with a paddle or spatula. The black paste is then added to the shellac and mixed uniformly by stirring. The result is a smooth flowing and working shellac. Other pigments can be treated in the same way. O. M. B.
The ingredients for this cast iron brazing may be had at any first-class drug store and should cost no more than about 50 cents. They consist of 1 pound of boric acid, 4 ounces pulverized chlorate potash, and 3 ounces carbonate of iron. These ingredients should be thoroughly mixed, and kept perfectly dry (a glass jar or bottle answering the purpose), and when wanted for use, a small amount should be taken and mixed with grain spelter. In trying this brazing for the first time, take a piece of cast iron of say one square inch cross-section, hold the broken parts together by clamps, and fit the break closely in order to form a strong joint. Use a gas forge if possible, but an ordinary blacksmith's forge will do if no gas forge is available. When a blacksmith's forge is used, use charcoal, and be sure to get a high heat. When the pieces of the casting are in place, heat the joint to a good bright red before applying the flux. Then apply it liberally with an iron rod, flattened on the end, and work along the fracture, gradually raising the heat to almost a white heat. Then shut off the heat and allow the casting to cool slowly. If this work is done carefully, the joint will be as strong or stronger than the original casting.
Another formula is: 1 pound of boric acid, 3 ounces of caustic soda, and 3 ounces of carbonate of iron. This is mixed with spelter in the same way as in the first formula, and must also be kept dry. The main points to keep in mind when brazing cast iron are to have the metal clean and free from grease; not to apply the flux until a bright red is reached and then to be sure to raise the heat high enough to make the mixture flow nicely. Ethan Viall.