OUR readers already know that veneering is the art of glueing a very thin sheet of valuable wood upon a thick piece of a cheaper description.

Veneer is laid either with a caul or the veneering hammer. The former is always required for curved work, of which it must be an exact counterpart; it may also, when flat, be employed for plain surfaces; the veneering hammer, however, can be used only for flat work.

The surface of the work, and both sides of the veneer, must be roughened all over by the tootli-ing-plane, which is fitted with a perpendicular iron, the edge of which is serrated like an exceedingly fine saw. The small grooves made by this tool are technically called keys or teeth, and afford the glue a much firmer hold than it could otherwise possess.

If the veneer is to be laid by a caul, this latter must now be prepared, and should be fully as large as the work, and several pair of screw-clamps must also be selected. Each pair of clamps consists of two strong bars of wood, connected at the ends by screw-bolts and nuts. The inner edges of the bars should be slightly convex, or rounding in the direction of their length, so that they may touch the middle of the caul and under side of the work earlier than the outer edges or margin. The bars must be adjusted to the proper distance apart, so that the caul and work may just slip between them, for if too much be left to screw up after laying the veneer, the glue will lose its fluidity before the pressure is applied, and the work may be unsound in consequence.

We will now proceed to lay a piece of veneer with a flat caul. The caul must be placed near the fire so that it may be made thoroughly hot, care, however, being taken not to scorch it; and the sides should be frequently changed to equalize the influence of the heat, which may otherwise distort the surface. The upper surface of the work, and both sides of the veneer having been toothed, they are next made very warm, and the surface of the work is brushed over quickly with very thin glue or size; the veneer is then glued and laid on the work, being hastily rubbed down by the outstretched hands of two or three workmen; the hot caul is then placed on the veneer, and the clamps are slipped on and screwed down at intervals of two or three inches. The heat of the caul quickly penetrates the thin veneer, making the glue exceedingly fluid, and the pressure supplied by the clamps soon expels the greater portion of it, and causes the veneer to bed very closely to the work. The clamps must be screwed down as evenly as possible, so that the surplus glue may escape freely from the centre of the work. This may generally be ensured by screwing down both ends of the clamps equally, so that the bars, which are slightly rounding or convex, may touch the centre of the work first, gradually yielding as the pressure increases, until they bear throughout.

The same method is pursued when laying veneer upon curved works, but the face of the caul, as before observed, must be an exact counterpart of the surface to be veneered. The clamps must not be removed until the work is quite cold; or for about twelve hours. The glue is not considered to be thoroughly hard under two or three days, and if it be disturbed before it is quite dry, the soundness of the work is endangered. Sometimes the work is laid on the floor, the veneer downwards, and is then covered with shavings, which exclude the air, and cause the drying to proceed more gradually.

The amateur will seldom, if ever, have occasion to veneer curved works, and will not, therefore, require apparatus such as clamps and cauls. The veneering hammer is the only tool required for laying veneer on flat surfaces. This hammer, which has a very wide and thin pane, may be purchased for about two shillings or half a crown. Sometimes the workman prefers to make the hammer himself. As this is not difficult of accomplishment, some of our readers may desire to do the same. The hammer head in this case is made of a block of hard wood, about three or four inches square, and a round handle is inserted in the centre. One of the sides is next sawn down about an inch, and a piece of sheet iron or steel, say an eighth of an inch thick, is tightly fitted into the kerf, and should project about one quarter of an inch. The edge of the sheet metal or pane must be rounded with a file and made quite smooth, so that it may not injure the surface of the veneer. The opposite side to that in which the pane is fitted should be rounded so that it may not hurt the workman's hand, as he will be obliged to press heavily on the head to make the hammer act efficiently.

Everything being in readiness, the surface of the work, which has been made as hot as prudence will permit, is hastily covered with very fluid glue, which should also be as hot as the water bath can make it. The veneer must next be brushed over with glue on the side which is to be laid on the work, and just before laying, it should be held before a fire of shavings to render the glue perfectly fluid, as it soon loses its heat, however expeditiously the operation may be performed. After turning the veneer down upon the work, it must be rubbed over with the outstretched hands of two or three people, the pressure being first applied at the centre and gradually extended towards the margin. The upper side of the veneer is now washed over with hot size, which serves the double purpose of imparting fresh heat to the rapidly-cooling glue, and lessening the friction of the veneering hammer, which we are now about to use.

One man would scarcely be able to lay a piece of veneer satisfactorily; and as the soundness of the work in a great measure depends upon the despatch with which it is conducted., as many hands as can be spared, or as can conveniently assist, generally lend their aid.

The pane of the hammer is applied at the. middle of the work; the operator bears heavily on the head, and slowly wriggles the tool by its handle towards the margin. He again returns to the centre, and works down a line a little to one side of the former course, and so on repeatedly, until the entire surface has been traversed.

During the operation the surface of the veneer must be frequently washed over with hot size, to lessen the friction of the hammer, and to supply fresh heat to the glue. Inattention to this precaution would probably result in the destruction of the veneer. The pressure applied to the narrow edge of the pane is apt to cause it to tear the veneer if the latter become nearly dry. The heat and moisture supplied by the size tend to make the veneer pliable, and greatly facilitate the escape of the glue, which accumulates in advance of the pane in its progress from the centre of the work to the margin, where it is discharged. The solidity of the work may generally be tested by tapping the surface all over with the back of the hammer; and if some of the blows produce a dull hollow sound, the veneer is not in actual contact at those parts with the foundation or work. The pane must again be applied to the faulty spots, and if the glue be too far set to yield, the inner vessel of the glue-pot may be placed thereon, to furnish the necessary warmth. The difficulty of the process materially increases with the magnitude of the work, and soundness is more uncertain than when cauls and clamps are employed. The hammer is very useful for laying narrow strips or for small works that can be quickly completed, and in such cases is generally used, although the before-named apparatus may be at hand.

If veneered works when in use be placed too close to the fire, the veneer is apt to become blistered, and it is impossible to rectify the mischief except by re-laying. To remove the veneer, the surface must be washed with boiling water, and then wiped with a coarse cloth, to remove any dirt or grease that may adhere to it. The article must next be placed with the veneer towards the fire, or a hot caul may be placed upon it. When thoroughly hot, the surface must be rubbed over with linseed oil, and again exposed to the fire, or supplied with a fresh caul. The oil will soon sink through the veneer, and soften the glue, when the edges of the veneer may be gently raised by a chisel, being very careful not to split it. The heat and application of oil must be continued until the veneer is entirely separated from the foundation.

Before attempting to re-lay the veneer, all the old glue must be scraped, off, after which either of the processes we have described may be adopted.