1556. French Waterproof Felting

1556.      French Waterproof Felting. This composition, heretofore regarded as a secret in France, has been adopted for use in the French navy. The information regarding this material was furnished by Mr. Parent to the "Journal of Applied Chemistry." The inoxidizable compound for waterproof is made thus: 1061/2 parts, by weight, India rubber, 175 parts finely sifted sawdust, 10 parts powdered sulphur, 25 parts slacked lime, 125 parts sulphate of alumina, 125 parts sulphate of iron, 10 parts hemp tow. To mix the above, use heated cylinders, so as to obtain a very homogeneous paste, which is made into thin cakes, and afterward divide into small pieces to be dissolved. To dissolve this substance, take 41/2 pounds spirits of turpentine, benzine, (common is preferable), petroleum, or sul-phuret of carbon, to 21/2 pounds of the mixture. It must be stirred 5 or 6 times during 24 hours, at the end of which time the mass will be thoroughly dissolved. The solution is then spread on the fabrics or articles to be preserved, by means of rollers, knives, or spatulas, adapted to the purpose. Apply as many coats as may be necessary, and then let it dry. As soon as the fabric is dry, it is passed under pasteboard laminating rollers, in order to give a lustre to the surface. The fabric is then rolled up on a hollow iron pipe, which is covered with cloth to prevent it sticking to the iron, and the whole placed in a copper 'pipe, with a perforated lid or cover; steam is then introduced at a pressure of 4 atmospheres, which pressure is maintained for 1 hour, at the end of which time the operation is ended. If it be desired to give these impermeable covers a black color, a solution of sulphate of iron, nut-gall and logwood is applied with a brush.

1557. To Make Waterproof Joint Closers

1557.    To Make Waterproof Joint Closers. Caps or joint closers can be made of about the same materials as the above by observing the following proportions: Dissolve 211/4 parts, by weight, of India rubber, in sufficient benzine; then mix with it 15 parts sawdust, 2 parts sulphur, 3 parts red lead, and 5 parts each of alum, slacked lime, and hemp tow, adding benzine to make the whole into a paste. For closing the joints on steam engines, hydraulic pumps, etc..

1558. To Render Articles Waterproof

1558.     To Render Articles Waterproof. A patent has recently been taken out in Paris for a method of rendering paper, cloth, cork, sponge, and other porous substances waterproof, as well as articles manufactured from these materials, including banknotes, envelopes, gloves, clothing, paper collars, umbrellas, labels, etc.. The process consists in dissolving paraffine, cut up in small slices, in pure naphtha or benzine, entirely free from fat or oil. The solution is to be made in a vessel with a glass stopper, and is to be shaken repeatedly until the result is accomplished. An excess of paraffine should be used, so as to make sure of having a perfectly saturated solution. The articles to be treated are immersed in this for a time, according to the thickness or porosity of the tissue, and arranged to secure either a complete saturation or the penetration of the liquid to any required depth. After removal, the articles are to be dried by the application of heat, or in the air. The solvent evaporates, leaving the paper or other substance saturated with paraffine impermeable to water, and capable of resisting the action of acids. Articles of dress, such as paper collars and wristbands, should be subjected to the action of a flat-iron or heated cylinder, in order to give them a high degree of polish. The applications of this process are manifold, and new ones are constantly suggesting themselves.