The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking. Paul N. Hasluck
for quick-cutting stones. Petroleum, paraffin, etc., however, are not advised, the oil hardening the stone and destroying its cutting properties; where it is used for thinning oil no more than is necessary for the purpose should be added; however, if the stone becomes dirty or gummed up, a very small quantity of paraffin or turps may be used for cleansing purposes, but it should be wiped off as soon as possible. The oil may be kept for use in a small oil-can (Fig. 449). Soap has been recommended for the same purpose. The stone is wetted and rubbed with soap, and more water is applied until a lather forms. This dries, and when the stone is required for use it is merely necessary to wet it slightly.
Fig. 444.—Oilstone Case.
WIPING OILSTONE.
When a tool has been sharpened, the oilstone should be wiped and the cover put on or the lid closed to keep away the dust of the workshop, which is often charged with particles of grit from glasspaper; if grit or other sharp particles lodge on the stone they will leave gaps in the next tool that is sharpened. An essential point is to preserve the original sharpness of the stone. A clean rag or cotton waste is preferable for wiping it after sharpening a tool, as shavings generally leave it dirty.
OILSTONE BECOMING HARD.
When an oilstone has been in use for some time its surface is apt to become hard, especially if certain oils—paraffin in particular—are used on it. The reason is that the pores of the stone are closed by the viscid or gummy oil, which contains particles of steel rubbed off in sharpening; when the stone is in this condition it is not touched by the tool, which rides upon a substance as hard as itself; therefore the stone fails to cut the tool. A mixture of oil and turpentine is often applied to hard stones to clean them and make them cut; for this purpose, also, they are sometimes boiled in soda water. Hard oilstones may be made to cut and give edges to tools by sprinkling a very little flour emery on them after the oil has been applied, but in this case it is the emery and not the stone that cuts.
Fig. 445.—Oilstone Case, Moulded.
LEVELLING AND RUBBING DOWN OILSTONES.
When an oilstone becomes uneven with wear it is necessary to level it. This may be done by glueing or tacking a sheet of glasspaper on a level board and rubbing the stone on the glasspaper. If the stone is of a very hard nature, emery cloth may be used. If the cloth is tacked down it can be taken up frequently and well shaken or beaten on the back to get rid of the oilstone dust, and so doing lengthens the life of the emery cloth. Another method is to use fine sand and water sprinkled on a level iron plate or sheet of glass, emery powder being used instead of the sand for hard stones. The face of the stone is rubbed on the metal or glass, the grit and water being replenished as required. This leaves a smooth and even surface. Some workmen level the stone with an old file, or hold it on the side of a revolving grindstone. The “strickle” method, described below, has just the same effect as emery cloth has, with, however, more trouble. Some workers will use no other method, however. An emery strickle is used by carding engine minders in cotton and woollen mills, from whom they can be obtained. For the benefit of those who cannot get an old strickle, make a substitute as follows: To (say) one gill of hot glue add about a dessert spoonful of ordinary glycerine, stirring well, and keep the mixture hot. Get a pine board 1 in. thick, from 4 in. to 6 in. wide, and any length up to about 2 ft., and having planed one surface true, and bored a 1/2-in. or 5/8-in. hole to hang it up by, lay it face upward upon a large sheet of paper. Coat the board with the hot glue, rubbing it in well and evenly with the brush, and at once cover quickly with a thick layer of coarse emery; pat this down all over with the flat of the hand; raise the board, shake off the superfluous emery, and give the board a smart rap or two on the bench or table top. Then put aside in a warm, dry place for twelve hours, and repeat the glueing, and covering with emery on the top of the first coat. Rap off all the loose emery, and again put aside to dry. Finally, give the surface a thin coat of boiled oil (with or without the addition of a little black paint), taking care that the interstices between the emery grains are well filled. It will be dry in two or three days, and then will be found to be a most effective appliance for keeping oilstones level.
Fig. 446.—Section of Cased Oilstone.
Fig. 447.—Section of Oilstone Case showing Points.
Fig. 448.—Section of Oilstone Case showing Rubbers.
Fig. 449.—Bench Oilcan.
CUTTING AND MENDING OILSTONES.
Sometimes it is required to cut an oilstone into pieces, and this may be done by rubbing across it the edge of a sheet of soft iron or mild steel, using sand and water as required. Or instead, a piece of hoop iron (such as that used on casks) may be used with emery, either we or dry, as the cutting agent; cutting is quicker when the emery is dry. Another method is to insert a piece of an old hand-saw into a wooden block and to rub the stone on this, the teeth being, of course, set uppermost. An uncased oilstone, if brittle, is easily broken by a sharp jar or fall, and the two pieces will be of but little use until mounted. Get a piece of well-seasoned mahogany for a case, and mortise it out so that both portions of the oilstone can be fitted in fairly tight. Then, with one of the cements previously described, bed both portions of the stone in the case, taking care to keep close the broken joint of the stone. Let the stone stand for a time to allow the cement to become set, after which the surface should be rubbed down with silver sand and water on a flat stone. If the stone is used with care the fracture will scarcely be detrimental.
EMERY OILSTONES.
Emery oilstones have been made for the last twenty-five years, but until quite lately they were too poor in quality to come into general use. The Whelden emery oilstone is manufactured from Turkish emery, one face being of fine and the other of medium coarse material. The coarser side is very fast cutting, and on it a 2-in. plane iron about 1/32-in. thick at the edge has been sharpened to a fine cutting edge in three minutes, as against seventeen minutes on a good Washita stone and thirty-six minutes on an Arkansas stone. The coarse side leaves the tool in about the same condition as a good Washita stone, and the fine side in about the same condition as a fine Turkey or soft Arkansas, better than a Washita, but not so fine as a good hard Arkansas. The emery oilstone has the advantage over any natural stone that it is quite uniform in texture, there being no hard or soft spots, cracks or fissures. They are not brittle, and can be dropped a reasonable distance without breaking. The stock size is the No. 10, which is 8 in. long, 2 in. wide, and 1 in. thick, but the makers advise the use of Nos. 12 and 15, the former being 8 in. long, 1 3/8 in. wide, and 1 3/8 in. thick, and the latter 2 in. wide and otherwise the same as No. 12. The lubricant used with these stones is water or paraffin, and therefore iron cases are preferable to wooden ones. All the usual shapes of slips, etc., are made in this emery stone.
OILSTONE SUBSTITUTES.
A very good substitute for an oilstone is to be made very cheaply with zinc and emery. Get a piece of zinc about 8 in. by 2 1/2 in., and tack it at the corners to a flat piece of