This section is from the book "A Treatise On Architecture And Building Construction Vol2: Masonry. Carpentry. Joinery", by The Colliery Engineer Co. Also available from Amazon: A Treatise On Architecture And Building Construction.
194. Pointing consists in scraping out the old mortar in the outer joints, to the depth of at least half an inch, and filling them with fresh mortar, which is well worked in with a trowel. The object of pointing is to prevent access of moisture to the interior of the joint.
195. Both old and new work require, in many cases, to be pointed up again after laying; in new work, if attention has been paid to laying the brick properly with good ruled joints for face brick, and neatly struck joints in common brick, "pointing up" may not be necessary; in fact, if the brick have been laid according to the usual specifications, it would be entirely unnecessary. But when new work has been poorly laid, or where old work requires renovating, pointing is often resorted to. If it is intended to point up new work, the raking out should be done with a piece of hard wood while the work is in progress; old work will have to be raked with an iron raker. After raking, the joints should be well swept with a hard broom. In hot, dry weather the wall should be kept wet while the pointing is being done.
196. For mortar, Portland cement, mixed with about an equal quantity of clean, fine, sharp sand, is preferable, but if cement cannot be obtained, the best quality of ground lime may be used. This should be run through a very fine sieve, and mixed with fine sand before wetting, in the same way as cement. The whole quantity required for the job should be made up at one time, and kept moist, by placing in a damp place shaded from the sun and wind; and before it is used, it should be beaten into a proper state of consistency with a wooden or iron beater.
197. Tuck pointing is made by first filling the joint flush with brick-colored mortar, and then cutting a narrow groove along the middle of the joint; in this is laid a putty paste, of the desired color, in such manner as to form a narrow ridge, the edges of which are trimmed so as to be parallel. This method gives the appearance of close joints, and disguises any irregularities in the work. In bastard tuck pointing, the ridge is wider, and is formed by a "jointer," having a Vor [ section, drawn along a straightedge.
198. Bead and key pointing differ from each other in that the first is made by a jointer having a semicircular section, producing a ridge of like shape; the second is formed by drawing along the joint a key having a circular form, pressing it in firmly, so as to compact the mortar.