When a scraper becomes dull (1) each edge is draw-filed, Fig. 121, so as to make it square and straight, with the corners slightly rounded. Sometimes the edges are rounded slightly from end to end to prevent digging. Frequently the scraper has its edges and surfaces ground square on an oilstone after the draw-filing that the arrises may be formed into smoother burs. (2) After filing, the scraper is laid flat on the bench and the arrises forced over as in Fig. 122. The tool used is called a burnisher; any smooth piece of steel would do. (3) Next, turn these arrises back over the side of the scraper. Fig. 123. Great pressure is not necessary to form the burs properly.

64. Sandpapering.—To know when to use and when not to use sandpaper is as much the sign of a good work­man as to know how to use the tools.

Sandpaper should never be used until all tool work has been done as well and carried as far as is possible. Sandpaper is, as its name implies, sand paper. In sand­ing a surface, this fine sand becomes imbedded in the wood and should an edged tool be used thereon it will be dulled. Slovenly work should never be done in expecta­tion of using sandpaper to fix it up. This practice is dis­honest. Sandpaper should not be expected to do the work of edged tools or disappointment will follow. The sandpaper sheet, for use, is usually divided into four parts, one of these parts being of good size for large work.

For flat surfaces these pieces are placed on a sand­paper block. This block is merely a piece of wood squared up to a length equal to that of the piece of paper and to such a width that the edges of the paper will extend far enough up the edges of the block to allow the fingers to grasp them firmly. Fig. 124. Do not waste the paper, by wrapping it around in such a way as to throw part of it on top of the block. The block should be held flat up­on the surface when sanding near an arris, otherwise the arris will be round­ed. The arrises should be kept sharp unless on a table leg, arm of a chair or something similar, in which the sharp Fig. 124. arrises would be likely to injure the hand or become splintered through usage. In such cases the sandpaper may be run along the arrises once or twice, just enough to remove the sharpness. Sometimes the plane is set shallow and drawn over the arris after the surfaces have been squared, to remove the sharpness.

On curved surfaces, the sandpaper is held free in the hand, no block being used. Fig. 115 illustrates the man­ner of sanding the convex curve of the coat hanger. The sandpaper should be rubbed along the grain and the rub­bing should proceed only long enough to smooth the piece and to bring out the grain clearly.

On the back of a piece of sandpaper will be found a number. This number indicates the relative coarseness of the sand sprinkled upon the glue covered paper. 00, 0,1, 13^ and 2 are the numbers commonly used; 00 being, finest and 2 relatively coarse., On table tops and sur­faces which are not very smooth to begin with, the coarse sandpaper is first used, this is followed by the next in coarseness and so on until the finest is used.

Never attempt to sandpaper surfaces or parts which are to be put together later on to form joints; the edge tools alone must be depended upon to secure proper smoothing.

65.Hammers.—Fig. 125 shows the two kinds of ham­ mers most commonly used by workers in wood.  The plain faced hammer has a flat face and is somewhat easier to learn to use than the bell faced hammer, which has a slightly rounded face.

The advan­tage of the bell-faced hammer lies in one's ability to better set a nail slightly below the surface without the assistance of the nailset. This is a very great advantage on outside or on rough carpenter work. This setting of the nail with the hammer leaves a slight depression, however, in the wood, and is there­fore not suited for inside finishing.

The handle of the hammer is purposely made quite long and should be grasped quite near the end.

66.Nails.—Nails originally were forged by hand and were therefore very expensive.  Later strips were cut from sheets of metal and heads were hammered upon these by means of the blacksmith's hammer, the vise be­ing used to hold the strips meanwhile. 

These were called cut nails.  Early in the nineteenth century a machine was invented which cut the nails from the sheet metal and headed them.

Steel wire nails have about supplanted the cut nails for most purposes. They are made by a machine which cuts the wire from a large reel, points and heads the pieces thus cut off.

Wire nails, like cut nails, are roughly classed by wood­workers as common, finishing and casing nails. Thin nails with small heads are called brads. Wire nails are bought and sold by weight, the size of wire according to the standard wire gage and the length in inches being taken into consideration in specifying the size and fixing the price per pound.

In former practice, the size of nails was specified ac­cording to the number of pounds that one thousand of any variety would weigh. Thus the term six­penny and eight-penny referred to varieties which would weigh six and eight pounds per thou­sand, respectively, penny being B c a corruption of pound. In pres­ent practice, certain sizes are still roughly specified as three, four, six, eight, ten, twenty and thirty-penny.

Common wire nails are thick and have large flat heads. They are used in rough work where strength is desired. Fig. 126A. Finishing nails, Fig. 126B, are used for fine work such as inside woodwork, cabinet work, etc. Casing nails, Fig. 126C, are somewhat thicker and stronger than finishing nails; they have small heads.

67. Nailing.—Especial care is necessary in starting cut nails. Fig. 127 shows two views of a cut nail. From these it will be seen that the sides of the nail form a wedge in one of the views while in the other they are parallel. The nail should be so started that the wedging action shall take place along, not across the grain.

In nailing through one piece into the edge of another, assume a position so that you can look along the piece into the edge of which you are nailing. If the nail is to be driven plumb, it must be sighted from two directions several times in the beginning of the nailing. Having driven the points of one or two of the nails slightly below the surface of the first piece, adjust the two pieces properly, force the points into the second piece, and, holding the parts firmly with the left hand, drive these nails into place. In starting a nail, place the board on a scrap of wood that the point shall not mark the bench top. Never try to change the direction of a nail after it has entered the wood by pounding it sidewise. This only bends the nail, does not change its direction but makes the point come out more quickly, if anything. Pull out the nail and start it in a new place.

 In nailing box bottoms on before starting a nail look at the nails pre­viously driven in the side pieces to see that your bottom nail will not strike one of these.

68.  Nailset.—Except  in  rough work, the nail should not be driven entirely in with the hammer or the wood will be marred. A nailset held as in Fig.  129 should be used to set the head of  the  nail slightly below the  surface  of the wood—about one thirty-second of an inch. A finger placed against the side of the nailset and allowed -to rest on the piece, of wood aids greatly in guiding the set,  which otherwise might jump off" the nail
head when the" blow is struck1-and indent the wood.                                       :

69. Withdrawing Nails.—Should it be necessary to withdraw a nail, place a block of wood under the head of the hammer, Fig. 130, to prevent marr­ing the\surface of the wood. If the nail is a long one, the size of the block used should be increased as the nail comes out, that the nail may not be bent.

70. The Screwdriver—Patent ratchet and spiral screw­drivers have come into quite common use among workers in wood. The old style, Fig. 131, however, is much better suited to elementary work than any of these special forms.

71. Screws.—Screws, like nails, are made entirely by machinery. They are packed in pasteboard boxes and sold by the gross.  The size of a screw is designated by the length in inches and the size of the wire from which it is'made;:thus, 1 inch No. 10 flathead bright screw.

The gage, of wire for nails and the gage of wire for screws should not be confused. Fig. 132 is a full-sized illustration of the gage used for determining the size of wire for nails. The numbers apply to the openings at the edge, not to the circular parts. The notch at No. 1 will just slip over No. 1 wire. Fig. 135 is a full-sized illustration of a wire gage for screws. The gage is slipped over the screw just below the head.

Flathead screws are used for ordinary work. Round­head screws are used because they are more ornamental. Fig. 133. Either kind may be made of steel or brass. Steel screws are often blued by treat­ing them with heat or an acid.

72. Fastening with Screws.

—Where  two  pieces of hard wood are to be fastened with screws, a hole just large enough to take in the shank of the screw must be bored in the up­ per part.  In the lower part, a
hole should be bored just large enough to take in the core of
the screw snugly. Fig. 134. For flathead screws, the hole should
be  countersunk  so  that  the head  may  be  flush  or sunk slightly below the surface of the wood. In soft woods, the boring of a hole in the lower piece may be  omitted.

73. Glue.—Nails  are  but seldom used in cabinet work to fasten parts together, glue be­ing used instead. Glue is manufactured from the refuse parts of animals.  Strippings of hide, bone, horn, hoofs, etc., are boiled to a jelly; chemicals are added to give it the light color. It is usually placed on the market in the form of dry chips.

Glue pots are made double, the glue being placed in one part and this placed in a larger one which contains water.

The glue is heated by the hot water and steam of the outer kettle.  To prepare glue, dissolve the dry chips in water. It is well to soak them over night unless quite thin. If the glue chips are thin they may be barely covered with water and the pot set in the outer kettle of boiling water. Some kinds of glue require less water. The glue should be stirred occasionally. It should be used while hot and should be made thin enough to flow easily when applied with a brush. If the wood is cold it will chill the glue. Best results are obtained by warming the wood in an oven.

Prepared liquid glues, to be ap­plied without heating, are com­mon. As these glues thicken with age, due to evaporation, they must be thinned occasionally. In cold weather they chill and must £ be warmed in hot water to bring them to a proper consistency.  

74. Clamps.—Clamps are used in the making of a glue joint to expel the glue from the surfaces of contact, forcing it up into the pores of the wood or, if too much has been applied, out on the sides of the joint. For holding small parts, the wood­en handscrew is used, Fig. 137.  To adjust this clamp, hold the handle of the shoulder spindle firmly in the left hand and the handle of the end   | ""l spindle in the right hand; revolve them about an axis midway be­tween and parallel to the spindles until the approximate opening of the jaw is obtained, Fig. 138. 

Place the clamp on the parts and screw the shoulder  spindle up tight, adjusting the  end  spindle when necessary :so that.,.. when  it  is tighten e,d the jaws of the clamp shall  be  parallel, Fig. 139.  In taking off .this clamp, the end spindle is the one which must be released.