CEMENTS.
Before cementing vulcanized rubber the surface should be roughened or
still better it may be seared with a red hot iron. For bicycle tyres
this is especially to be recommended.
_Cement for Cuts in Bicycle Tyres, Rubber Belts, etc._--Carbon
bisulphide, 5 ounces; gutta-percha, 5 ounces; caoutchouc, 10 ounces;
fish glue, 2½ ounces. After it is applied and has dried the excess can
be removed with a wet knife. Bad cuts should first be stitched up.
_Bicycle Tyre Cement to fasten Tyres to Rims._--Equal parts of pitch
and gutta-percha are melted together. Sometimes two parts of pitch are
prescribed. This cement has extended application.
_Cement for Paper Boats and for Mending Rubber Goods._--Fuse together
equal parts of pitch and gutta-percha, and to this add about 2 parts of
linseed oil containing 5 parts of litharge. Continue the heat until the
ingredients are uniformly commingled. Apply warm.
_Waterproof Cement._--Shellac, 4 oz; borax, 1 oz; boil in a little
water until dissolved, and concentrate by heat to a paste.
_Another._--10 parts of carbon disulphide and one part of oil of
turpentine are mixed, and as much gutta-percha is added as will readily
dissolve.
_Cement for Mending Hard Rubber._--Fuse together equal parts of
gutta-percha and genuine asphaltum; apply hot to the joint, closing the
latter immediately with pressure.
_Glue to Fasten Leather, etc., to Metals._--1 part crushed nut galls
digested 6 hours with 8 parts distilled water and strained. Glue is
macerated in its own weight of water for 24 hours, and then dissolved.
The warm infusion of nutgalls is spread on the leather; the glue
solution upon the roughened surface of the warm metal; the moist
leather is then pressed upon it and dried.
_Marine Glue, Various Formulæ._--I. Dissolve 1 part of india rubber
in 12 parts of benzole, and to the solution add 20 parts of powdered
shellac, heating the mixture cautiously over a fire. There is great
danger of conflagration. Apply with a brush.
II. Caoutchouc, 1 oz; genuine asphaltum, 2 oz; benzole or naptha, q. s.
The caoutchouc is first dissolved (as described in chapter XII.), and
the asphaltum is gradually added. The solution should have about the
consistency of molasses.
_Cement for Vulcanized India Rubber._--Stockholm pitch, 3 parts;
American resin, 3 parts; unmixed india rubber, 6 parts; oil of
turpentine, 12 parts. Heat and mix very thoroughly. More oil of
turpentine may be added as required.
_Gutta-Percha Cement for Leather._--Soak gutta-percha in boiling water.
Soften in benzole after cutting up for a day. Heat on a water bath
until the greater part of the benzole is expelled. When cool it will
solidify. Use by heating.
_Cement for Rubber Shoes._--
(1) Chloroform 280 parts.
India rubber (masticated) 10 ”
(2) India rubber 10 ”
Resin 4 ”
Venice turpentine 2 ”
Oil of turpentine 40 ”
For first solution dissolve by mastication. For second, melt the finely
divided gum with the resin, add the Venice turpentine and finally the
oil of turpentine. Use heat if necessary. Mix both solutions finally.
To apply, saturate a piece of linen with the cement and apply to the
spot previously coated with the cement. As it dries apply a little more
as required. A finishing varnish is given in the last chapter. Parkes’
cold curing process may be applied as described in chapter XI.
_Chatterton’s Compound_ for uniting sheets of gutta-percha in cable
cores and for general work with gutta-percha coated wires.--Stockholm
tar, 1 part; resin, 1 part; gutta-percha, 2 parts.
_Waterproofing for Wooden Battery Cells._--Resin, 4 parts;
gutta-percha, 1 part; boiled oil, a little.
_Another Formula._--Burgundy pitch, 150 parts; old gutta-percha in fine
shreds, 25 parts; ground pumice stone, 75 parts. Melt the gutta-percha
and mix with the pumice stone and then add the pitch, melting all
together. Apply melted and smooth off with a hot iron.
_Cement for Celluloid._--Shellac, 1 part is dissolved in spirits of
camphor 1 part, with 3 to 4 parts strong alcohol. It is applied warm
and the parts united must not be disturbed until the cement is hard.