Glue

“ A most excellent Glue.—Beat an ounce of isinglass to shreds: dissolve it gradually in a pint of brandy, by means of gentle heat, and then strain the solution through a piece of fine muslin. The glue thus obtained should be kept in glass closely stopped. When required for use, it should be dissolved with moderate heat, when it will appear thin, transparent, and almost limpid. When applied in the manner of common glue, its effect is so powerful as to join together the parts of wood stronger than the wood itself is united. ”

“ By heating, the glue dissolves rapidly and remains liquid, when cold, without loss of adhesive power. Any desirable consistence can be secured by varying the amount of saccharate of lime. Thick glue retains its muddy color, while a thin solution becomes clear on standing. ”

“ For actual sizing purposes good and fine varieties of glue are only used, or sometimes the manufacturers prepare their own size by boiling to glue dried calves’ heads, or rabbit skins deprived of their fur, scraps of parchment, etc. For cheap woollen hats, glue is used in place of shellac. The cloth manufacturer procures his glue mostly in the form of a jelly. ”

“ Much glue is converted into "size," which is a weak gel used as a filling rather than as an adhesive agent. A low-grade glue is often therefore preferred for such purposes, as having "body" rather than "strength." ”

“ As glue is required, cut out a portion and melt in the usual way. Expose no more of the made glue to the atmosphere for any length of time than is necessary, as the atmosphere is very destructive to made glue. Never heat made glue in a pot that is subject to the direct heat of a fire or a lamp. All such methods of heating glue cannot be condemned in terms too severe. Do not use thick glue for veneering or joints. In all cases work it well into the wood, in a similar manner to what painters do with paint. ”

“ ANOTHER METHOD. A very strong glue, that will resist water, may be also made by adding half a pound of common glue, or isinglass glue, to two quarts of skimmed milk, and then evaporating the mixture to the due consistence of the glue.
TO MAKE PARCHMENT GLUE. Take one pound of parchment, and boil it in six quarts of water, till the quantity be reduced to one quart; strain off the fluid from the dregs, and then boil it again till it be of the consistence of glue.
The same may be done with glovers’ cuttings of leather, which make a colorless glue, if not burnt in the evaporation of water. ”

“ Skin Glue.—In the preparation of skin glue the materials used are the parings and cuttings of hides from tan-yards, the ears of oxen and sheep, the skins of rabbits, hares, cats, dogs and other animals, the parings of tawed leather, parchment and old gloves, and many other miscellaneous scraps of animal matter. Much experience is needed in order to prepare a good glue from such heterogeneous materials; one blending may be a success and another a failure. ”

“ Glue thus prepared will keep for years, and is at all times fit for use, except in very cold weather, when it should be set in warm water before using. To obviate the difficulty of the stopper getting tight by the glue drying in the mouth of the vessel, use a tin vessel with the cover fitting tight on the outside to prevent the escape of the spirit by evaporization. A strong solution of isinglass made in the same manner is an excellent cement for leather.
A valuable glue is made by an admixture with common glue of one part of acid chromate of lime in solution to five parts of gelatine. ”

“ Glue is always used for cloth. As piles of pieces of cloth shift about in glueing, a touch of glue is given to two corners of the pile and left to dry a little. These corners hold the pieces of cloth in position whilst being glued and prevent the edges from being smeared. In glueing cloth it must be seen that the glue is well rubbed into the grain or artificial indentations. ”

“ The solutions of glue are kept warm over a water bath and thoroughly stirred every time before pouring them upon the plates. The formation of a film on the surface of the glue solution must be strictly avoided. ”

“ A glue which will dissolve in cold water is not good glue, or if it melts readily in hot water without being soaked an hour or two in cold water, it is not first-class. If it has a dead white look it is not good. Good glue should be glossy and semi-transparent, and should soften and swell in cold water, but not dissolve in it. ”

“ The best glue is transparent, hard in the cake, free from spots, of an amber color, and has little or no smell. A good practical test for glue is to soak it in water till it swells and becomes jelly-like. The more it swells without dissolving the better the quality. Poor glue dissolves. Glue is sometimes bleached, becoming brownish white in color, but it is somewhat weakened thereby. ”

“ The workman has to know from experience just how thick the glue has to be for the work he has on hand. A hardwood piece of work requires a thinner glue than soft wood. The average consistency of glue should be about like that of thin syrup, and should be applied hot to the work. Sometimes in cold weather [Pg 116] the glue “sets” quickly; then the pieces to be glued should be heated so that the glue may be kept soft. When the pieces are put together clamp them up quickly or rub them together, forcing out the surplus glue from the joint. ”

“ Adhesives for Various Uses.—Waterproof glue. Use a good quality of glue, and dissolve it in warm water, then add one pound of linseed oil to eight pounds of the glue. Add three ounces of nitric acid.
Leather or Card-board Glue. After dissolving good glue in water, to which a little turpentine has been added, mix it with a thick paste of starch, the proportion of starch to glue being about two to every part of glue used. The mixture is used cold.
A fine Belt Glue. Dissolve 50 ounces of gelatine in water, and heat after pouring off the excess water. ”

“ Glue is an important by-product of the great packing houses. Those in touch with the industry know how extensively glue enters into the manufacture of articles of everyday use. The general public hardly realizes that glue is used not only in making wood-joints and veneers, but in the production of paper, of silks, hats, carpets, rugs, and hundreds of other necessities. ”

“ In some cases glue may be abated, or altogether dispensed with, by employing plaster of paris sufficiently diluted and worked into the colors, by which they will acquire the consistency and appearance of oil painting, without employing their limpidness or allowing the colors to separate, while they will acquire a good surface, and keep their place in the dry with the strength of fresco, and without being liable to mildew, to which animal glue is disposed, and to which milk, and other vehicles recommended in this mode, are also subject. ”

“ There is a good deal of glue made in France from bones, freed from the phosphate of lime by muriatic acid. This is a poor article, possessing little cohesive force. It dissolves almost entirely in cold water, which is the best criterion of its imperfection. Glue should merely soften in cold water, and the more considerably it swells, the better generally speaking, it is.
Some manufacturers prefer a brass to a copper pan for boiling glue, and insist much on skimming it as it boils; but the apparatus I have represented renders skimming of little consequence. ”

“ White lead, sulphate of lead, zinc white, or chalk in quantities varying from 4 to 8 per cent. are frequently mixed with the melted glue to improve the appearance of the finished product. Thus, according to analyses by A. Faisst, Russian glues contained in 100 parts foreign admixtures as follows:
The so-called patent glue which is opaque and of a white color is produced by adding considerable quantities of white lead to ordinary glue. ”

“ Cold or liquid glue has supplanted hot glue in furniture repairing, gluing up intricate work, and in places where it is impracticable to use hot glue either on account of its setting too rapidly, or where heat is not available. Liquid glue does not hold as well nor as permanently as hot glue when properly used, but for many kinds of work it is perfectly satisfactory. ”

“ It should be applied quickly in a warm room and the parts to which it is applied clamped up quickly before the glue chills. It is the glue which penetrates the wood that holds the parts together and not a layer of glue between the joined edges or surfaces. It is therefore evident not only that joints and surfaces should be well smeared with glue, hot and thin enough to be quickly absorbed, but also that the parts should be clamped up quickly while the glue is still hot so as to prevent any surplus from remaining in the joint. ”

“ The characteristic qualities of animal glue, making it peculiarly suitable for that use, are a low absorptiveness of water and a consequent high degree of fluidity, facilitating its application by mechanical means, high elasticity, and great tensile strength. ”

“ From the best pale glue, 1 lb.; water, q. s.; dissolve in a double glue-pot or water bath, and of pale-brown sugar, 1⁄2 lb., continue the heat until the mixture is complete, and pour it into moulds; or pour it on a marble slab, and when cold cut it into small pieces and dry them in the air. This glue is very useful to draughtsmen, architects, &c., as it dissolves almost immediately in warm water, fastens paper, &c., without the process of damping, and may be softened for many purposes with the tongue. When great strength not required, 4 oz. more of sugar may be used. ”

“ Jeffrey’s marine glue is formed by dissolving india-rubber in four parts of benzene and adding two parts of shellac; it is extensively used, being easily applied and drying rapidly and hard. Another water-proof glue which contains no gelatin is obtained by heating linseed oil with five parts of quicklime; when cold it forms a hard mass, which melts on heating like ordinary glue. ”

“ Such glue passes into solution at 122° F., and dissolves entirely on heating to 144.5° F. Heating to a higher temperature should be avoided.
Glue as a binding agent. Glue solution is used for bind-together pulverulent substances, such as mineral colors in the manufacture of colored paper and paper-hangings, in painting in distemper, in the size of the gilder; or it is mixed with plaster of Paris or chalk for the manufacture of plastic masses which become hard on drying, such as stucco-work, papier-maché, etc. ”

“ Elastic Glue.—Although elastic glue is less durable than rubber, and will not stand much heat, yet it is cheaper than rubber, and is not, like rubber affected by oil colors. Hence it is largely used for printing rollers and stamps. For stamps, good glue is soaked for 24 hours in soft water. The water is poured off, and the swollen glue is melted and mixed with glycerine and a little salicylic acid and cast into molds. The durability is increased by painting the mass with a solution of tannin, or, better, of bichromate of potassium. Printing rollers require greater firmness and elasticity. ”

“ This is the reason why good sound glue made from scraps of skin is preferred by those artisans who may be considered the principal consumers, such as cabinet-makers, carpenters, turners, instrument-makers, wood-carvers, carriage-builders, brush-manufacturers, bookbinders, paper-manufacturers, etc., all of them requiring glue of the greatest possible adhesive power. ”

“ Common black or dark glue, while possessing all the adhesive and other essential qualities of fine colored glue, has heretofore, owing to its color, been confined in its use to such purposes in the arts where color was not essential. ”

“ Glue should be of a bright brown or amber colour, free from specks or blotches, nearly transparent, and with but little taste or smell. It should be hard and moderately brittle, not readily affected by moisture in the atmosphere, and should break sharply, but if it shivers as easily as a piece of glass it is much too brittle, though at the same time it must not be tough and leathery. ”

“ In the foregoing statement only some of the principal uses of glue have been enumerated, and there can be no doubt that with an increase in the knowledge of its nature and properties, a wide field is still open for progress in this industry. ”

“ In gluing them up, there is nothing particular to be observed, except that the glue must be very hot, laid on well with a stiff brush, and the stuff clamped between two thick boards, which have been planed perfectly true on the faces ”

“ Between two or more glues of any one type, actual experiment is the only safe guide. Most glue men will give you good advice; but above all, keep accurate records of results of the different grades used. When you have found the right glue, keep to it. ”

“ The strongest glue is that obtained from skins, more especially from the hides of oxen and cows. That809 obtained from the bones, cartilages, and tendons, is weaker.
Glue, Liq′uid. Prep. (Dumoulins.) Soft water, 1 quart; best pale glue, 2 lbs.; dissolve in a covered vessel by the heat of a water bath, cool, and add, gradually, of nitric acid (sp. gr. 1·335) , 7 oz.; when cold put it into bottles. Very strong, and does not gelatinise. For the ‘LIQUID GLUE’ sold in the shops, see Chinese cement.
Glue, Marine. Prep. 1. India rubber (cut small) , 1 part; coal tar or mineral naphtha, 12 parts ”

“ General directions for gluing.9 Before applying glue to the parts to be fastened together, it is a good plan to assemble them temporarily without glue, to see that all the parts fit. When it is desirable that a certain part, as the panel, in panel construction, should not be glued in place, it is a wise precaution to apply wax, soap, or oil to its edges before insertion. Since hot glue sets quickly, it is necessary after the glue is applied to get the parts together as soon as possible. One must learn to work fast but to keep cool. ”