IX.—Amalgamate by heat:
| India rubber | 100 ounces |
| Rosin | 15 ounces |
| Shellac | 10 ounces |
Then dissolve in bisulphide of carbon.
X.—Make the following solutions separately and mix:
| (a) | India rubber | 5 ounces |
|---|---|---|
| Chloroform | 140 ounces | |
| (b) | India rubber | 5 ounces |
| Rosin | 2 ounces | |
| Venice turpentine | 1 ounce | |
| Oil of turpentine | 20 ounces |
{23}
Cement for Patching Rubber Boots and Shoes.—
| I.— | India rubber, finely chopped | 100 parts |
|---|---|---|
| Rosin | 15 parts | |
| Shellac | 10 parts | |
| Carbon disulphide, q. s. to dissolve. | ||
This will not only unite leather to leather, india rubber, etc., but will unite rubber to almost any substance.
| II.— | Caoutchouc, finely cut | 4 parts |
|---|---|---|
| India rubber, finely cut | 1 part | |
| Carbon disulphide | 32 parts |
Dissolve the caoutchouc in the carbon disulphide, add the rubber, let macerate a few days, then mash with a palette knife to a smooth paste. The vessel in which the solution is made in both instances above must be kept tightly closed, and should have frequent agitations.
III.—Take 100 parts of crude rubber or caoutchouc, cut it up in small bits, and dissolve it in sufficient carbon bisulphide, add to it 15 parts of rosin and 10 parts of gum lac. The user must not overlook the great inflammability and exceedingly volatile nature of the carbon bisulphide.
Tire Cements.—
| I.— | India rubber | 15 grams |
|---|---|---|
| Chloroform | 2 ounces | |
| Mastic | 1/2 ounce |
Mix the india rubber and chloroform together, and when dissolved, the mastic is added in powder. It is then allowed to stand a week or two before using.
II.—The following is recommended as very good for cementing pneumatic tires to bicycle wheels:
| Shellac | 1 ounce |
| Gutta percha | 1 ounce |
| Sulphur | 45 grains |
| Red lead | 45 grains |
Melt together the shellac and gutta percha, then add, with constant stirring, the sulphur and red lead. Use while hot.
| III.— | Raw gutta percha | 16 ounces |
|---|---|---|
| Carbon bisulphide | 72 ounces | |
| Eau de Cologne | 2 2/3 ounces |
This cement is the subject of an English patent and is recommended for patching cycle and motor tires, insulating electric wires, etc.
IV.—A good thick shellac varnish with which a small amount of castor oil has been mixed will be found a very excellent bicycle rim cement. The formula recommended by Edel is as follows:
| Shellac | 1 pound |
| Alcohol | 1 pint |
| Mix and dissolve, then add: | |
| Castor oil | 1/2 ounce |
The castor oil prevents the cement from becoming hard and brittle.
A cement used to fasten bicycle tires may be made by melting together at a gentle heat equal parts of gutta percha and asphalt. Apply hot. Sometimes a small quantity each of sulphur and red lead is added (about 1 part of each to 20 parts of cement).
Cements For Leather.—
| I.— | Gutta percha | 20 parts |
|---|---|---|
| Syrian asphalt, powdered | 20 parts | |
| Carbon disulphide | 50 parts | |
| Oil of turpentine | 10 parts |
The gutta percha, shredded fine, is dissolved in the carbon disulphide and turpentine oil. To the solution add the asphalt and set away for several days, or until the asphalt is dissolved. The cement should have the consistency of honey. If the preparation is thinner than this let it stand, open, for a few days. Articles to be patched should first be washed with benzine.
| II.— | Glue | 1 ounce |
|---|---|---|
| Starch paste | 2 ounces | |
| Turpentine | 1 drachm | |
| Water, a sufficient quantity. | ||
Dissolve the glue in sufficient water with heat; mix the starch paste with water; add the turpentine, and finally mix with the glue while hot.
III.—Soak for one day 1 pound of common glue in enough water to cover, and 1 pound of isinglass in ale droppings. Then mix together and heat gently until boiling. At this point add a little pure tannin and keep boiling for an hour. If the glue and isinglass when mixed are too thick, add water. This cement should be used warm and the jointed leather pressed tightly together for 12 hours.
IV.—A waterproof cement for leather caoutchouc, or balata, is prepared by dissolving gutta percha, caoutchouc, benzoin, gum lac, mastic, etc., in some convenient solvent like carbon disulphide, chloroform, ether, or alcohol. The best solvent, however, in the case of gutta percha, is carbon disulphide and ether for mastic. The most favorable proportions are as follows: Gutta percha, 200 to 300 parts to 100 parts of the solvent, and 75 to 85 parts of mastic to 100 parts of ether. From 5 to 8 parts of the former solution are mixed with 1 {24} part of the latter, and the mixture is then boiled on the water bath, or in a vessel fitted with a water jacket.
V.—Make a solution of 200 to 300 parts of caoutchouc, gutta percha, india rubber, benzoin, or similar gum, in 1,000 parts of carbon disulphide, chloroform, ether, or alcohol, and of this add 5 to 8 parts to a solution of mastic (75 to 125 parts) in ether 100 parts, of equal volume and boil together. Use hot water as the boiling agent, or boil very cautiously on the water bath.
VI.—Forty parts of aluminum acetate, 10° B., 10 parts of glue, 10 parts of rye flour. These materials are either to be simultaneously mixed and boiled, or else the glue is to be dissolved in the aluminum acetate, and the flour stirred into the solution. This is an excellent cement for leather, and is used in so-called art work with leather, and with leather articles which are made of several pieces. It is to be applied warm.
Rubber Cement For Cloth.
—The following formulas have been recommended:
I.—Caoutchouc, 5 parts; chloroform, 3 parts. Dissolve and add gum mastic (powder) 1 part.
II.—Gutta percha, 16 parts; india rubber, 4 parts; pitch, 2 parts; shellac, 1 part; linseed oil, 2 parts. Reduce the solids to small pieces, melt together with the oil and mix well.
III.—The following cement for mending rubber shoes and tires will answer similar purposes:
| Caoutchouc in shavings | 10 parts by weight |
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