Dissolve glue by the aid of a water bath, evaporate till a thick fluid is obtained, add an equal weight of glycerine, continue the evaporation with stirring until the remaining water is driven off; run it out on a marble slab to cool. This composition might be advantageously applied to the manufacture of printers' rollers, and similar articles.
(c) 3 parts glue broken into small pieces should be covered with 8* parts of water, and left to stand for some hours; 1/2 part of hydrochloric acid and 3/4 part of sulphate of zinc must then be added, and the whole exposed to a temperature of about 185° F. during 10 or 12 hours. Allow the compound to settle.
(d) A liquid glue possessing great resisting power, recommended for wood and iron, is prepared, according to Herz, as follows: - Clear gelatine, 100 parts; cabinet-makers' glue, 100 parts; alcohol, 25 parts; alum, 2 parts; the whole mixed with 200 parts of 20 per cent. acetic acid, and heated on a water-bath for 6 hours.
(e) An ordinary liquid glue, also well adapted for wood and iron, is made by boiling together for several hours 100 parts glue, 260 parts water, and 16 parts of nitric acid.
(b) Caoutchouc, 20 gr.; chloroform, 2 fl. oz.; dissolve and add 4 dr. of powdered mastic; let it macerate for a week; must be kept cool and well corked.
Fine pale glue, 1 lb.; dissolve over a water bath in sufficient water, aid brown sugar, 1/4 lb.; continue the heat till amalgamation is effected; pour on a slab of slate or marble, and when cold cut into squares. Used by moistening with the tongue. (See also ii. 78, 300.)
Malt, crushed small, 1 lb.; warm water, 2 gal. Mix; heat the whole to 145° F.; add of potato starch 5 lb.; raise the heat to 160° F., and mash for about 25 minutes, or until the liquid becomes thin and clear; it must then be instantly run off, and raised to the boiling point to prevent the formation of sugar; after boiling for 3 or 4 minutes, the whole must be filtered and evaporated to dryness by a steam heat. (See also ii. 73, 85, 450.)
(a) 100 parts finely chopped rubber, 15 rosin, 10 shellac, dissolved in a sufficient quantity of bisulphide of carbon. Used for uniting pieces of rubber.
(6) Rubber, 15 gr.; chloroform, 2 oz.*, mastic, 1/2 oz. The two first-named to be mixed, and after the rubber is dissolved add the mastic in powder; allow to macerate for a week.
Take 2 parts of sulphur, and 1 part, by weight, of fine black-lead; put the sulphur in an old iron pan, holding it over the fire until it begins to melt, then add the graphite; stir well until all is mixed and melted; then pour out on an iron plate, or smooth stone. When cool, break into small pieces. A sufficient quantity of this compound being placed upon the crack of the iron pot to be mended, can be soldered by a hot iron in the same way a tinsmith solders his sheets. If there is a small hole in the pot, drive a copper rivet in it and then solder over it with this cement. (See also ii. 89.)
-For the cement-ing of iron railing tops, iron'gratings to stoves, etc, the following mixture is recommended; in fact, with such effect has it been used as to resist the blows of a sledge-hammer. This mixture is composed of equal parts of sulphur and white-lead, with about one-sixth proportion of borax, the three being thoroughly incorporated together, so as to form one homogeneous mass. When the application is to be made of this composition, it is wet with strong sulphuric acid, and a thin layer of it is placed between the two pieces of iron, these being at once pressed together. In five days it will be perfectly dry, all traces, of the cement having vanished, and the work having every appearance of welding.
(a) 1 lb. clean iron borings, pounded fine in a mortar, 2 oz. sal ammoniac in powder, 1 oz. flowers of sulphur. The whole mixed by pounding, and to be kept dry, tor use, mix 1 part of the above with 20 of iron, borings pounded, adding water to the consistence of mortar.
(6) 2 lb. clean iron borings, 1 oz. (lowers of sulphur, 1 oz. sal ammoniac.
(c) 98 parts of fine iron borings through a sieve, 1 flowers of sulphur, 1 sal ammoniac. Mix and dissolve in boiling water when required for use.
(d) Mix 1 lb. fine borings, 1/2 oz. sal ammoniac, pounded small, 1/2 oz. spirits of salts, and a little water. Prepare the joint by bringing the inner joint rings of the flanges together - screwing up the bolts firmly; in this condition there should be an annular space between the flanges of from 1/4 in. to 3/8 in. in width; a strand of rope-yarn or any soft fibre should now be stuffed to the bottom of the joint, so as to prevent the jointing material from being driven through in the process of caulking. A good hammer, a caulking iron rather thinner than the joint, and a flat piece of wood or sheet iron should be in readiness. Take a suitable quantity of fine cast-iron borings, free from dust, and which may be passed through a sieve to remove large pieces; next dissolve a very small piece of sal ammoniac in water, say a drachm to a quart. In the absence of sal ammoniac to mix up the borings with, the urine of any animal does quite as well. Now mix the borings with, sufficient of the fluid to cause them to adhere together in lumps when compressed in the hand. It is now ready for use.