Note 42 — Chapter XVI

You may be told that perfect joints do not require much clamping, but a perfect joint is impossible, and as a practical matter, only the skilled workman or the most accurate machinery can make even a good joint of much length, so great is the difficulty of avoiding little inaccuracies. Besides this, there is always the liability to more or less springing or change of shape on the part of the pieces. The joint which was good when you stopped planing may not be as good by the time the glue has set, particularly if the gluing does not immediately follow the jointing. In addition to this, the pressure from clamping at only one or two points, or at points too far apart, may force the joint to open elsewhere. Do not infer from this that even the beginner should be content with a poor joint, with the idea that it can be squeezed and jammed to a sufficiently good fit by applying muscle to the clamps. Of course this jamming or mashing of the fibres to fit occurs, to a microscopic degree, in even the best joint, and it can sometimes be done to a perceptible extent with soft wood, but to do this intentionally is very unworkmanlike, and the greatest care should be taken to make as good a joint as possible before gluing and applying the clamps. Do not, however, flatter yourself that you can make so accurate a joint that you can afford to neglect proper clamping, unless, in such cases as that shown in Fig. 488, you adopt the old-fashioned way of rubbing the two edges together and then leaving the rest to the glue, but this is not so good a process for the beginner, except with small pieces, such as corner-blocks (see Corner-blocks). See Jointing.