Rubber Cement. — The ordinary rubber mending tissue is a conven ient article for repairing cloth, and also for flexible rubber surfaces, as hot-water bottles and the like. Use this mending tissue for umbrellas, raincoats, and similar articles requir ing a tight waterproof joint. Lay the mending tissue over the break or tear. Place on the other side a piece of the same fabric and press lightly with a hot iron.
To mend a hot-water bottle, heat an artificial rubber band or a piece of pure rubber with hot iron, as a poker, until it becomes sticky, and lay it quickly over the hole or crack. Let dry before using. Rubber over shoes can be mended in the same way. But hot-water bottles will keep longer and not require mending if emptied, dried, blown up, and corked tightly before they are put away.
Or apply a patch of oiled silk by means of mending tissue and a hot iron, but do not use the iron hot enough to melt or injure the rubber.
Or dissolve 1 ounce of gutta percha in ?fr pound of chloroform. Wash the parts to be cemented with a dilute solution of caustic potash or soda. Cover each freely with this gutta percha solution and let dry for half an hour. Then warm each surface in the flame of a candle and let dry under pressure.
Or shave India rubber with a wet knife or shears to thin strings or shreds like yarn. Fill a glass fruit jar about one fourth full of these shreds and fill it up with high-grade benzine. Let stand, shaking occa sionally, for four or five days or until completely dissolved. Thin with ben zine, or add more rubber if sary to make the mixture of the con sistency of molasses.
Or dissolve India rubber in highly rectified spirits of turpentine.
Or dissolve 7 grains of India rub ber in 1 ounce of chloroform, and add 2 drams of shellac varnish.
The above are suitable for patch ing boots and shoes, for cementing rubber and leather, and either of them to wood. Clean the parts to be
cemented by washing with a dilute solution of caustic potash or soda, and apply two or three coats to each surface. Let dry under pressure.
Or melt together equal parts of gutta percha and pitch. Apply hot.
Or melt together pound of gutta percha, 2 ounces of India rubber, 1 ounce of pitch, ounce of shellac, and 2 ounces of boiled linseed oil.
Or heat 5 pounds of Venice tur pentine, stir in 8 ounces of shellac and 2 ounces of India rubber cut to shreds, and stir over gentle heat un til dissolved. When 'dissolved, add 10 ounces of liquid storax. Do not allow the mixture to boil or burn. Apply hot.
The above are suitable for cement ing metals, leather, rubber, or cloth, especially flexible surfaces.
Or cut up 2 ounces of pure India rubber in 1 pound of bisulphate of benzoin until the mixture is of the consistency of thick cream. Apply to both surfaces, warm the parts, and let dry under pressure.
This cement is used by shoemakers to put invisible patches on shoes, and is also suitable for mending har nesses, splicing leather straps, and the like.
To apply, shave the edges of the leather on a long bevel, lay over them a wet cloth, and press with a hot iron to take up any grease that may be present, but take care not to use an iron hot enough to burn or take the life out of the leather. Pour the cement on both surfaces quite thick ly, and spread with a brush so as to fill the pores of the leather. Warm the parts over a flame for a few sec onds until the cement becomes sticky, or " tacky," apply quickly, and ham mer until firmly set. Keep the ce ment tightly corked in a cool place.
To fasten leather to iron or steel, spread over the metal a thin, hot solution of good glue, and soak the leather in a warm solution of gall nuts before placing it on the metal. If fastened in this way the leather will tear before separating.