SPECIAL ADHESIVES Marine Glne.—Dissolve 1 ounce of finely divided India rubber in RI pounds of crude naphtha. Let stand or 3 weeks and shake frequently. Add 5 pounds of shellac, melt with gentle heat, and stir until evenly dis solved. Pour on a marble or stone slab to cool and break in pieces like glue for use. When required, melt with gentle heat, apply a thin coating to the edges to be joined, and press firmly together. This ce ment is used in foundries, for calk ing ships, joining blocks of marble and granite, joining wood to iron, etc. It is suitable for all heavy rough work exposed to the air.
Or dissolve in separate vessels by means of gentle heat 3 ounces of India rubber in rectified sulphuric ether free from alcohol. Mix the two solutions. When cool, bottle and cork tightly for use. This is suitable for fine work. Both of the above re sist the action of hot and cold water, and of most acids and alkalies. Wood, leather, and other materials cemented by them will part almost anywhere except at the place mended. Thin this glue with ether and apply with a brush along the seams where leather is sewed, as the soles of shoes. This renders the seam air-tight and practically unbreakable. The last two cements are probably the strongest known.
To prepare the above in large quantities dissolve 1 pound of India rubber in 5 gallons of cold naphtha, and add to this solution an equal weight of shellac. Melt with gentle heat and stir while melting until thoroughly dissolved. This is ex tremely tenacious and is insoluble.
Lead and Oil Adhesives.—Linseed oil boiled to a varnish with litharge, and white lead ground in linseed oil, with or without various preparations of glue or other ingredients, make a class of adhesives which have valu able fireproof and waterproof quali ties.
Mix 4 ounces of linseed oil with 4 ounces of slaked lime, and boil until stringy. Pour into tin molds and let dry indoors or in the shade. This will dissolve when wanted like glue. It will withstand fire and water.
Or boil 4 ounces of linseed oil with 4 ounces of litharge until the mix ture is stringy, and add S ounces of melted glue of the consistency of mo lasses. Use this cement for leaders, the joints of wooden cisterns or casks, and similar places. It requires 3 or 4 days to harden, but renders wooden vessels air-tight and water tight.
Or mix equal quantities by weight of linseed oil and litharge. Stir in porcelain clay or well-dried pipe clay to the consistency of stiff mortar. Thin, if desired, with oil or turpen tine. Apply this substance to the outside of buildings.
Litharge Cements.—Mix 2 ounces of litharge, 1 ounce of unslaked lime, and 1 ounce of flint glass. Pulverize into fine powder, mix, and when re quired make into a stiff paste with boiled linseed oil.
Or pulverize brick or well-burnt clay to Et fine powder. Mix 1 pound of litharge with 13 pounds of pul verized brick or clay, and add boiled linseed oil to make a stiff mortar. Dampen the surface to which this is to be applied and use as mor tar.
The above are suitable for cement ing stone, wood, or iron, filling leaks, mending cracks, and other similar purposes.
Or mix powdered litharge with glycerin to the consistency of Fiutty. Used for fastening metal tops to glassware, mending holes in tinware, ironware, and the like.
Or mix 3 ounces of red lead, 3 ounces of white lead, 3 ounces of man ganese, 3 ounces of silicate of soda, and 1 ounce of litharge. Use this cement for holes or cracks in steam or water pipes.
Or mix white lead ground in oil with powdered red lead to the con sistency of putty.
Or mix equal weights of red lead and white lead with boiled linseed oil to the consistency of putty. Ap ply the cement to a washer of cloth or canvas and tighten up the joint. It dries like stone. This and the last are employed by engineers to make metallic joints.
Or use white lead mixed with oil to mend broken china and glassware, and to fill cracks in roofs, cisterns, and the like.