Page:Cassells' Carpentry and Joinery.djvu/39

Rh of strong paper coated with powdered glass secured to the paper with glue. The different

Fig. 114.—Glasspaper Rubber.

grades of glasspaper are numbered from 3 to 0, and even finer. For properly using glasspaper a rubber (Fig. 114) is required, this being a shaped wooden block faced with cork. In use the glasspaper is folded round it. Glasspaper has entirely replaced the old-fashioned sandpaper, which was a similar material, except that fine, sharp sand was used instead of powdered glass.

Rasps and Files.—Woodworkers' rasps are generally half-round, though sometimes flat. The wood rasp (Fig. 115) is coarser than the cabinet rasp. The ordinary half-round wood file (bastard cut) is shown at Fig. 116. Both range from 4 in. to 14 in. in length. The usual files used for keeping saws in order chiefly are known as triangular taper (Fig. 85), and have already been alluded to.

Fig. 115.—Half-round Wood Rasp.

Fig. 116.—Half-round Wood File.

Grindstones.—The grindstone (Fig. 117), many varieties of which are obtainable, is an appliance for removing a superfluous thickness of metal, not for producing a good edge. It should be of a light grey colour, even throughout.

Oilstones.—On an oilstone the joiner sharpens his tools, which have been previously ground to shape on the grindstone. The oilstones in most general use are four in number—the Charnley Forest, Turkey, Washita, and Arkansas. The Charnley Forest is of a greenish-slate colour, and sometimes has small red or brown spots—the lighter the colour the better; it may take a little more rubbing than other stones to get an edge on the tool, but that edge will be keen and fine. Some Turkey oilstones are of a dark slate colour when oiled, with white veining and sometimes white spots; they give a keen edge, but wear unevenly, and also are very brittle; they are notoriously slow-cutting, and are expensive. The cheapest oilstone at first cost is the Nova

Fig. 117.—Treadle Grindstone on Iron Stand.