Woodwork Joints Part 4

[Ill.u.s.tration: Fig. 86.--How the Saw is held for the first Cut.]

Cut down the other line in a similar manner, and then with a chisel of suitable width carefully chop away the waste material. The wood may be placed edge way upon the bench, or in the vice, and the chisel should be held vertically. The hole which has been bored with the twist bit will allow the chips which are cut away to offer little or no resistance to the chisel blade. The chiselling should not all be done from one side, or a chipped under-edge will be the result; it is better to chisel the work until half-way through and then turn the other edge of the wood uppermost and again begin to chisel from the top. This method will finish the cutting in the centre of the work and prevent burred and ragged or chipped edges at the shoulder.

[Ill.u.s.tration: Fig. 87.--Third, or Horizontal Cut.]

[Ill.u.s.tration: Fig. 88.--Chiselling Operation.]

CUTTING THE SHOULDERS.--With regard to working the piece B, Fig. 81, place the wood against the bench stop or in the vice, and taking up a 3/4-in. chisel carefully cut away a small channel, as shown at Fig. 88; treat the other shoulder lines in a similar manner. If the marking knife or penknife blade has been used with a fair amount of pressure so as to score the fibres of the wood, this small channel, which is to form a guide for the saw, will quickly and easily be cut. Next place the wood in the vice or on the cutting board as shown at Fig. 89, and begin by sawing lightly at the back edge as shown. When the saw has entered the wood 1/4 in. gradually bring the handle down from position A to position B (dotted lines) whilst the saw is in motion. Continue sawing until just on the gauge line; then treat the other shoulder lines in a similar manner.

[Ill.u.s.tration: Fig. 89.--Sawing the Shoulders.]

CHISELLING AWAY WASTE.--Fix your wood firmly in any suitable manner, vice or otherwise, and, holding your chisel tilted as at Fig. 90, pare away the blacked portion 1; then pare away the blacked portion 2; after which hold the chisel flat and by gradual operations pare away the dotted lines 3, until you come down to the gauge line; then repeat the method of cutting on the opposite side of the wood. If any difficulty be experienced by chipped or ragged edges whilst chiselling, it can easily be overcome by chiselling alternately from the outside of the wood, so that the finish of the chisel cut takes place in the centre of the work.

Some prefer to chisel away the waste by placing the wood on its edge and using the chisel vertically instead of horizontally. The same methods (1, 2 and 3) hold good in this case.

[Ill.u.s.tration: Fig. 90.--Chiselling away Waste.]

JOINTS OTHER THAN AT 90.--The two pieces forming a bridle joint are not always at right angles, as at Fig. 81; in many instances it is necessary that the joint be at other than 90 degrees. The work, however, is treated in a similar manner, with the exception that an adjustable joiner's bevel is used instead of a try square to mark out the shoulder lines, and that a change of direction in the grain of the wood will occur when chiselling out the work. Fig. 91 indicates the change in the grain of the wood, and the adjustable joiner's bevel is also shown.

[Ill.u.s.tration: Fig. 91.--Bridle Joint at Angle other than Right Angle.]

[Ill.u.s.tration: Fig. 92.--Sawing off Waste from Bridle Joint. (See reference on page 39.)]

THE TONGUED AND GROOVED JOINT

The tongued and grooved joint is used in one form or another throughout the whole of the woodworking trades, covering, as it does, a great variety of work from the laying of flooring boards to the construction of dressers, bookcases and other cabinet work.

FLOORING and match boarding generally have the tongues worked on the solid board, and examples of a few of the various types are shown as follows:--

[Ill.u.s.tration: Fig. 93.--Tongued and Grooved Flooring Board.]

[Ill.u.s.tration: Fig. 94., Fig. 95. Method of Nailing Hardwood Floors.]

Fig. 93 shows the end view of the ordinary 7/8-in. "Tongued and Grooved Flooring board," as used in the construction of floors for mills, workshops and cottage property. This type of flooring is nailed to the joists in the ordinary manner, no attempt being made to conceal the nails used.

Fig. 94 is a section of flooring which is generally made of hardwood, such as maple, oak, or jarrah. It is used in positions such as ballroom and skating rink floors, etc., the tongue and groove being worked in such a manner that the joint covers the nails as shown. Each nail is driven into its position at one edge of the board, the groove holding the next board and hiding the nail (Fig. 95).

[Ill.u.s.tration: Fig. 96.--Tongued and Grooved Matchboarding, with Bead on One Side.]

[Ill.u.s.tration: Fig. 97.--Tongued and Grooved Matchboarding, with Bead at Each Side.]

[Ill.u.s.tration: Fig. 98.--Matchboarding, Tongued, Grooved and Vee'd.]

Fig. 96 shows an example of matchboarding known as "Tongued, Grooved and Beaded" on one side only, and Fig. 97 shows a similar type tongued, grooved and beaded on both sides. This variety of matchboarding is known in the trade as "T. G. and B." It is used for nailing on framing to form part.i.tions for rooms, offices, etc., for panelling corridors, etc., and for making framed and ledged doors, building tool houses, cycle sheds and other outhouses.

Fig. 98 is an example of matchboarding that is tongued, grooved and vee'd on one side, and Fig. 99 shows tongued, grooved and vee'd both sides.

These are used for similar purposes to Figs. 96 and 97, and many prefer the V matchboarding variety because it is more easily painted than the beaded variety.

The object of working a bead or beads on matchboarding is to break the jointing of the various pieces and to aim at ornamental effect; also to prevent unsightliness should the timber shrink slightly. When a moderate amount of shrinkage takes place, as is nearly always the case, the joint at the side of the bead appears to the casual observer to be the fillet or channel worked at the side of the bead. If the tongues are not painted before the work is put together, the shrinkage will cause the raw wood to show and thus make the joint too much in evidence.

[Ill.u.s.tration: Fig. 99.--Matchboarding Vee'd Both Sides.]

[Ill.u.s.tration: Fig. 100.--Double-tongued Matchboarding.]

[Ill.u.s.tration: Fig. 101.--Double-dovetailed, Tongued and Grooved.]

Fig. 100 shows a "Double tongued and grooved" joint used in the wholesale cabinet factories. It is preferred for the jointing of cabinet stock, and the amateur can make a similar joint by working two grooves and inserting loose tongues.

Fig. 101 is the end view of a "Double-dovetailed, tongued and grooved"

joint, and Fig. 102 is a sketch of a similar joint having only one dovetailed tongue.

From a constructional point of view Fig. 101 is far and away the best joint that has yet been produced. Unfortunately, however, there is not at the present time any hand tool that will economically produce it, owing probably to the fact that the joint is the subject of a patent. The dovetail tongue tapers slightly throughout its entire length, gripping the joint on the principle of the wedge and squeezing the glue into the pores of the wood.

[Ill.u.s.tration: Fig. 102.--Joint with Single Dovetail Tongue and Groove.]

[Ill.u.s.tration: Fig. 103.--(A) Cross Tongue. (B) Feather Tongue.]

[Ill.u.s.tration: Fig. 104.--Method of Secret-nailing Hardwood Flooring Boards.]

CABINET-WORK JOINTS.--With regard to tongued and grooved joints which apply more particularly to the jointing of cabinet work, Fig. 93 is produced by planes which are specially made for the purpose. One plane makes the tongue and another the groove. The handiest sizes to buy are those which joint 3/8 in., 5/8 in., and 3/4 in. timber, it being usual to dowel or loose-tongue thicker boards. The 3/8 in. part.i.tions (or, as they are sometimes called, dustboards) between the drawers of a sideboard or dressing chest are in good work jointed in this manner. The 5/8 in. and 3/4 in. ends and tops of pine or American whitewood dressing tables, wardrobes, etc., call for the larger sized plane.

LOOSE TONGUES.--There are two methods of jointing with loose tongues, viz., the use of the cross tongue, Fig. 103 A, and the use of the feather tongue, Fig. 103 B. Cross tongues are the stronger when glued in their position and can be used very much thinner than feather tongues. Feather tongues are cut diagonally across the grain as ill.u.s.trated.

[Ill.u.s.tration: Fig. 105.--Cradle for Planing.]

Fig. 105 is a cradle for planing up loose tongues to the required width (generally 7/8 in.). Two grooves are made in a piece of 1-1/4 in.

hardwood; one groove is used for planing the width way of the tongue and the other for planing the edge way. These tongues can be cut to accurate size on a circular saw bench if power and machinery are at hand.

APPLICATIONS OF THE JOINT.--Fig. 106 is a sketch of a portion of a sideboard top, showing the plough groove ready worked out to receive the tongue; the other half of the top is treated in a similar manner. It will be noticed that the groove is not worked through the full length of the board, but stopped about 1-1/4 in. from each end; this leaves a square joint at each end of the top on which the moulding is worked. If the groove be run through the board it looks very unsightly when the mould is finished.

Fig. 107 is a shaped spandrel, such as is fixed in the recess of a sideboard or cupboard or shop window fitment. It is of such a width that, were it cut from a wide board, the shaped portion would be apt to break off owing to the short grain at C. The shaping is therefore built up out of three separate pieces, the grain running as indicated. The loose tongue is represented by the dotted line and a section is shown of the joint at the line A B. At the opposite corner the tongue is left blind, _i.e._, not run through the edge. This is the method that should be used when the shaping is above the level of the eye.

[Ill.u.s.tration: Fig. 106.--Part of Sideboard Top; grooved with ends left blind. (The boards are shown upright.)]

[Ill.u.s.tration: Fig. 107.--Shaped Spandrel for Recess.]

Fig. 108 shows part of a carcase of a dressing table. The drawer runner A is shown grooved across the end to receive a cross tongue; this cross tongue engages a similar groove in the front bearer. This method of fastening the runner to the bearer is in everyday use.

[Ill.u.s.tration: Fig. 108.--Part Carcase of Dressing Table.]

[Ill.u.s.tration: Fig. 109.--Framed Writing Table Top.]

Fig. 109 is a writing table top. The centre boards are first jointed and glued up, after which the ends and sides are grooved ready to receive the cross tongues. The hardwood margins are shown at one end and at the front, and the grooves are arranged so that, on completion, the marginal frame stands above the top just the amount of the thickness of the leather which will cover the table. In some cases the margin at the end runs the same way of the grain as the top, thus allowing for slight shrinkage. Cross tongues would of course be used in this case.

Fig. 110 is a sketch showing one-quarter of a barred or tracery cabinet door. An enlarged section of the astragal mould which is grooved to fit on the bar which forms the rebate is also shown.