Читать книгу The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking - Paul N. Hasluck - Страница 174

It is surprising, considering the importance of the subject, how little is known generally of the art of nail-driving. Very many really creditable pieces of carpentry or joinery are ruined completely by the unskilful driving of the nails used in their construction. This result must follow if the correct method be not adopted. Many things must be considered before the nail is driven home, as will be seen from the following. In starting to insert a nail, it should be held between the thumb and the next two fingers of the left hand, and struck lightly with the hammer (see Fig. 460). In Fig. 461 A represents the side of a box and B one of the ends, to which the side is in the process of being nailed. It must be remembered that the nail is retained in position by cohesion and friction, and therefore it must be considered how to give full effect to these. The nails are being driven in an oblique direction; this is on account of their entering the end grain of the piece B, C D showing that they cut across the grain or fibres, thus rendering them less liable to draw out. Fig. 462 illustrates the manner in which the unskilled worker would probably drive them. A comparison of the nails at c d with the corresponding ones in Fig. 461 will at once show the former to be the better method. Fig. 463 illustrates the angle of a box turned round to show that the nail should be very carefully retained in an upright position with relation to the end, or as a result it will surely find its way out at one side or the other, as in Fig. 464. When driving nails near the end of the stuff as just described, a bradawl of suitable size should invariably be used, as this lessens not only the danger of the nail passing out at the side, but also that of splitting the material. Fig. 465 illustrates the manner in which the bradawl should be used. It is grasped as seen, and firmly pressed into the wood with a motion of twisting—that is to say, turned first to the right and back again to the left in a succession of short half-turns until deep enough for the purpose. It is often driven with a hammer; but this is more with the object of saving time, and often results in the awl leaving the handle, and is not advocated. If the bradawl be driven into the board as at E (Fig. 465) it must of necessity split the wood; if the awl is driven as at D, it will cut its way without injury into the stuff. The nail is at times liable to twist or turn in the grain after starting; this must at once be rectified, or the board will be split. The hammer must be held as near the end of the handle as convenient, especially in driving large nails; as greater power then is gained. The nail must be struck fairly upon the centre of its head, care being taken that the hammer does not glance off, as such an accident would probably both bend the nail and damage the work. All nails are more or less of a wedge form; as a consequence, nails of the clasp shape should be driven as B, C (Fig. 465), the width or side of nail being parallel to the grain of wood; but those that are chisel-pointed must be driven as at A (Fig. 465), that is, across the grain. If A be driven in the manner shown at H, the wedge shape of the nail will split the board. Fig. 466 shows two pieces of wood nailed together, the nails being clinched at the back, as in making a ledged door. Of course, wrought nails must be used, A being a rose-head and B a clasp nail. As these nails are usually punched below the surface on both sides of the work, the clasp should be used where convenient, as a smaller hole is made at the back. For punching the nail head below the surface of the work, the steel set is used; a square set or “punch” is shown by Fig. 467, and a round one by Fig. 468. The method of holding the set is made clear by Fig. 469.

Fig. 461.—Nailing together a Box.

Fig. 462.—Incorrect Nailing.

Fig. 463.—Side View of Correct Nailing.

Fig. 464.—Careless Nailing.

Fig. 465.—Bradawls and Nails in Wood.

Fig. 466.—Clinched Nails.

Fig. 467.—Square Nail Set or Punch.

Fig. 468.—Round Nail Set or Punch.

Fig. 469.—Using Nail Set or Punch.