Woodwork joints

THE principal aim of this Volume is to provide the A woodworker with full information as to the uses, and clear practical directions as to the making, of every joint he may at any time be likely to encounter. Those of us whose occupation or recreation is woodworking are familiar with numerous joints which we make and use in our own way. It is possible, however, that there are many which we do not make well, not because we lack skill or care, but because we are unfamiliar with some simple rule which governs either the setting out or the method of using the tool ; whilst probably there are many others which might suit our purpose better, but which we neglect because their existence has never occurred to us.

To be successful in woodwork construction the possession of two secrets is essential - to know the right joint to use, and to know how to make that joint in the right way. The woodwork structure or the piece of cabinet-work that endures is the one on which skilful hands have combined to carry out what the constructive mind planned. And it is just here that the present Volume will help, not alone the beginner who wishes preliminary instruction, but also the expert who desires guidance over ground hitherto unexplored by him.

The Table of Contents - and more particularly the exhaustive Index at the end of Volume - will show that practically every joint in cabinet-work and ordinary joinery is dealt with. In the case of the Bridle Joint, the Halved Joint, the Mortise and Tenon Joint, and the Dovetail Joint, the actual tool operations - setting out, gauging, marking, sawing, chiselling, paring, etc. - are fully explained ; and the fact that nearly sixty illustrations are devoted to the subject of Dovetailing is but one indication of the care which has been taken in making the directions clear and complete. As the methods of working are almost similar in the case of other joints, it has not of course been deemed necessary to repeat these detailed instructions in every chapter.

In the preparation of the Volume the Publishers have secured the services of Mr. William Fairham, by whom most of the chapters have been written and illustrated. Although intended for the practical man, and not professing to be a graded course of “educational woodwork,” the Volume is one which Manual Training Instructors will find of the greatest value in conducting woodwork classes. No book hitherto published contains such a variety of illustrations of joints, almost all of which will form suitable exercises of practical educational importance in a Manual Training course.

In conjunction with the other Volumes in The Woodworker Series “Details of Cabinet Construction,” “Staining and Polishing,” etc., this Volume, it is hoped, will 'leave the woodworker in possession of a store of information which, associated with his own practical knowledge and skilled experience, will enable him - if he so pleases - to reach to the highest and most advanced branches of his craft.

The glued joint in its various forms is in use in every country in the world, and is frequently met with in mummy cases and other examples of ancient wood- work. Alternative names under which it is known are the butt joint, the rubbed joint, the slipped joint, whilst in certain localities it is known as the slaped (pronounced slayped) joint.

The Glued Joint is made by planing two pieces of timber so that when placed together they are in contact with each other at every point ; they are then usually united with glue. Fig. i shows a sketch of a butt joint in its simplest form. In Fig. 6 is shown the method of holding the joint whilst being glued; the upright portion is held rigid in the bench vice, thus leaving the left hand to hold the piece which is to be jointed, whilst the right hand operates the glue brush. The pieces of wood which form a butt joint may be glued together with or without the aid of cramps or artificial pressure. If the joint is to be made without cramping, the two surfaces of the timber are warmed so as not to chill the glue. The surfaces are then glued and put together and rubbed backwards and forwards so as to get rid of the superfluous glue. This rubbing is continued three or four times until the joint begins to adhere. Care must be taken that the boards are in their correct relation to each other. They are then put aside to dry.

The better the glue penetrates into the pores of the wood, the stronger the joint will be ; for this reason timber of the loose-fibred variety, such as pine, etc., will hold up at the joint better than hardwoods like teak and rosewood. The glue used for jointing should be neither too thick nor too thin; the consistency of cream will be found suitable for most purposes. It should be nice and hot, and be rapidly spread over the surface of the wood.

If light-coloured woods, such as pine, satin-wood, sycamore, etc., have to be jointed, a little flake white should be procured and mixed into the liquid glue. This will have no detrimental effect on its adhesive qualities, and it will prevent the glue showing a thin black line on the joint. An alternate method which answers well on ordinary work is to rub the joint with a piece of chalk and wipe the surplus amount away previous to glueing.

Broad surfaces of close-grained hardwood, which generally present a shiny surface to the eye, are usually carefully roughened with a fine toothing plane blade previous to glueing.

Supporting the Joint. — The jointed boards should not be reared up against a " bench leg " or wall without having any support in the centre, as dotted line at Fig. 5, because in all probability they will fracture before the glue has time to set; and, when we go to take them up to renew working operations, we shall be annoyed to find that they have assumed a position similar to that shown at Fig. 5, and this will, of course, necessitate re- jointing.

A correct method to adopt is shown at Fig. 4. Here we have supported the joint by rearing up against the wall a couple of pieces of batten, one at each end of the board, thus supporting it throughout its entire width until the glue is thoroughly set. The two or more pieces of timber in a butt joint adhere by crystallisation of the glue and atmospheric pressure. A well-fitted joint made with good quality glue is so strong that, when boards of three feet and upwards are jointed together by this method, the timber in most cases will break with the grain sooner than part at the joint.

Butt joints may be cramped up, if desired, and it is customary to warm them as previously stated. In the absence of the usual iron cramp, the amateur may make an excellent wooden arrangement as shown in Fig. 21. This can be made out of any odd pieces of timber that happen to be handy. Two blocks of hardwood are screwed on the base board at a suitable distance for the work in hand ; the boards to be jointed are glued and placed in position between the blocks ; and the two hardwood wedges are inserted and hammered in opposite directions to each other, thus exerting the desired pressure.

When jointing, care should be taken to first plane up the boards true on one side — i.e., take them out of winding. The method of testing for this is shown at Fig. 23, and it may with advantage be used when jointing the edges of the boards. Two laths or strips of wood are planed up to exactly the same width, having their edges straight and parallel. One edge of each lath may, if desired, be bevelled a little. The method of using these " twist sticks " or " winding laths " is to put them on the board as shown at Fig. 23, and sight along their top edges. The winding laths, being much longer than the width of the board, show up the irregularity greatly pronounced.

The Tools generally used for making the butt joints are : — The jack plane, for roughing the edges, etc. The wooden trying plane (or iron jointing plane) for trueing up the work. The set square for testing purposes. The winding laths and straight edge.

The Method of Work is as follows : Each board is in turn put in the vice and planed straight lengthwise ; it is then tested with winding laths and a set square (the latter method is shown at Fig. 20). The boards are then put on the top of one another as at Fig. 2 and tested with a straight edge ; they should appear true as shown at Fig. 2 ; if they show faulty as at Fig. 3 the joints must be again fitted until the required degree of accuracy is obtained. Difficulties may be avoided by care in selecting timber suitable for jointing, and it must be remembered that timber shrinks circumferentially (the heart side becoming round) as Fig. 24. If the timber be jointed with all the heart side one way as at Fig. 24, the tendency will be for it to cast as shown by the single line. If the timber be alternated as at Fig. 25, the tendency will be to cast wavy, whereas if quartered timber can be obtained it will stand practically straight as the tendency to shrink is in thickness only. The grain of quartered timber is shown in Fig. 26.