This section is from the book "A Practical Treatise On The Joints Made And Used By Builders", by Wyvill J. Christy. Also available from Amazon: Practical treatise on the joints made and used by builders.
Glued or Glued Up Joint is one in which glue is used between the edges of boards, etc, to unite their surfaces or to impart additional strength to the junction. It is effected by shooting the edges perfectly true, cleaning and warming them. They are then thinly coated with hot glue, and rubbed together until almost all of it is forced out and what is left is nearly set. The motion of one piece on the other need be but slight - an inch or two each way only - and as soon as they feel inclined to stick they must not be moved again. As a general rule, all glued joints should be feather tongued, but glueing is used as little as possible in good joinery excepting in the joints down panels, the untrammelled groove and tongue affording better opportunities for shrinkage and the display of tasteful mouldings. Almost all small mortises and tenons, after being fitted and trimmed and left as long as possible, are put together with glue and wedged, and if the glue used be of the best quality it is but little affected by atmospheric changes. The carpenter, of course, never uses glue, and as to joinery, whatever assistance it may lend to good work, no doubt glue is a fast friend to bad work. In external work white lead replaces glue.
This is the ordinary glued joint strengthened by a block or blocking of prismatic form, and is common in stairs, built-up mouldings, cornices, columns, etc. Fig. 108 shows the joint between a tread and its rebated riser stiffened with blocks of triangular section, which discharge the useful function of checking disagreeable creaking.
Grooved and Feathered Joint is formed when uniting two boards with a slip feather of hard or obliquely-cut wood or iron tongue inserted, as in Fig. 109, in corresponding grooves, which are run by means of a plough, as explained under Ploughed and Feathered Joint. The same term is, however, frequently used for the common grooved and tongued, or ploughed and tongued joint, where the tongue is not detached but worked on one of the boards, as noticed under Grooved and Tongued Joint.
Grooved and Rebated Joint is made, as shown in Fig. 110, by combining a rebate with a groove and tongue. It offers a superior hold for edge-nailing when adopted for flooring.
Grooved and Tongued Joint - This is much in vogue in joinery for stopping rays of light and the passage of air and dust, and is invaluable for allowing shrinkage to occur without sacrificing effect, provided a moulding of some kind is struck or planted on either side of the seam. The joint is shown in Fig. 111, and is made by sinking with the plough on the edge or side of a board a rectangular cavity, or recess, or groove, and working on the edge of another with, a rebate plane or the side fillister - by taking a rebate out of each side of the edge - a projecting fillet 01 tongne that will exactly fit the groove. In the case of floor and other boarding the groove and tongue are so situated as to retain the surfaces in a true plane. This joint is also called ploughed and tongued, grooved and feathered, and ploughed and feathered, but it is more correct to apply the last two terms only where iron or slip feathers are used.
Grooved Tongued and Beaded Joint occurs as shown in Figs. 95 and 98 when a quirked bead is stuck on the tongued edge of a board, so that when shrinkage causes the tongue to draw a little out of the groove the opening and its shadow may look like a second quirk or part of the moulding.
Grooved Tongued and Mitred Joint is best explained by reference to Fig. 112. It possesses the qualities of strength and effectiveness.
Half Mortise and Tenon Joint is a kind of mortise and tenon whereof the mortise is cut through or has only one side. It is common in the heads of door and window frames.