This cement adheres immediately, and possesses a high degree of elasticity. It may be used to advantage for joining together the glass panes of hot-houses.
III. Dissolve, without application of heat, rubber 2 parts and gum mastic 6, in 100 of chloroform. This cement is perfectly transparent. It should be applied as quickly as possible, as it sets in a very short time.
Soft rubber cement. Melt 10 parts of tallow in a brass pan and gradually add 150 parts of rubber in small pieces, and stir constantly until all the rubber is dissolved. Keep in readiness a well-fitting lid to be able to extinguish the flame immediately in case the rubber catches fire. When all is melted stir in 10 parts of slaked lime.
This cement is especially adapted for sealing bottles containing caustic substances, such as nitric acid, etc. It remains always tenacious, being therefore suitable for cementing bodies exposed to repeated shocks.
Hard rubber cement. Rubber, 150 parts; tallow, 10; red lead, 10.
This cement is prepared in the same manner as the above. The addition of red lead gives it a red color, and solidifies it in a short time to a mass as hard as stone.
Elastic cement. Carbon disulphide, 8 ozs.; fine rubber, 1 oz.; isinglass, 4 drachms; gutta-percha, 1 oz. Dissolve the solids in the fluid.
This cement is used for cementing leather and rubber. For use the leather is roughened and a thin coat of the cement applied and allowed to dry completely; then the two surfaces to be joined are warmed and placed together and allowed to dry.
Marine glue. This cement, which is only a glue in name, is water-proof, and can be used to cement metal, wood, glass, stone, pasteboard, etc., and is especially adapted for caulking vessels.
Suspend 10 parts of rubber inclosed in a bag in a vessel containing 120 parts of refined petroleum, so that only half of the bag is immersed, and allow it to remain ten to fourteen days in a warm place. Then melt 20 parts of asphalt in an iron boiler and add the rubber solution in a thin jet, and heat the mixture, while constantly stirring, until it is perfectly homogeneous. Pour it into greased metallic moulds, where it forms into dark-brown or black plates difficult to break. In using it, it should be melted in a kettle placed in boiling water to prevent its burning, which it is very apt to do, as it is a bad conductor of heat. After it has been liquefied remove the kettle from the water and place it over a fire, where it can be heated, if necessary, to make it more fluid, to 302° F., carefully stirring it to prevent burning.