Figure 46.—Cold-Chisel. There are more flat cold-chisels than all other shapes. They are easily made in the farm shop and it is good practice. They are usually made from octagon steel. Different sizes are needed according to the work in hand. A piece of 5⁄8″ steel 6″ long makes a handy cold-chisel for repair work.
Figure 47.—Cape Cold-Chisel. It may be tapered both ways or one way to a cutting edge, or one edge may be rounded.
Figure 48.—(1) Tinner’s Punch. Made of octagon steel in sizes to fit the rivets. The cutting end is flat and has sharp edges made by roll filing. It should be about 7″ long and from 3⁄8″ to 1⁄2″ in diameter, according to the size of rivet and thickness of sheet metal to be punched. (2) Prick Punch. Usually made rather short and stocky. It may be 1⁄2″ or 5⁄8″ diameter and 41⁄2″ to 5″ long. (3) Hot-iron Punch. Made in many sizes and lengths. The taper should be the same as the drawing.
Figure 49.—(1) Blacksmith Vise. The old-fashioned leg vise is the most satisfactory for the blacksmith shop. It should have 5″ jaws. (2) Power Post Drill. Belt power is practical for the post drill in a farm shop. The hand crank may be easily attached when needed.
The bench vise should be heavy. A vise is used for bending iron hot from the forge. Unless the jaws are large, the hot iron is likely to heat the vise sufficiently to draw the temper. Heavy jaws are solid enough to support the iron when it is being hammered. Often heavy hammers are used for this purpose. A heavy vise holds the work solid, because it may be screwed so much tighter than a light vise. A heavy vise will hold light work, but a light vise will not hold heavy work. Heavy vises cost more, but they are cheaper in the end and more satisfactory at all times. A leg vise with five-inch jaws weighs about sixty pounds; five and one-half-inch jaws, eighty pounds. A machinist’s vise is made to bolt on top of the bench. It will answer for blacksmith work on the farm, but is not as good as the old-fashioned leg vise. A machinist’s vise is very useful in the garage, but it would hardly be necessary to have two heavy vises. The pipe vise belongs on a separate bench, which may be a plank bracketed against the side of the room.
Drill-Press.—The most satisfactory drill-press for use on a farm is the upright drill that bolts to a post. There is usually a self feed which may be regulated according to the work. The heavy flywheel keeps the motion steady, and because there is no bench in the way, wagon tires may be suspended from the drill block, so they will hang free and true for drilling. Often long pieces of straight iron are drilled with holes spaced certain distances apart. It is easier to pass them along when they lie flat side down on the drill block. To use a drill properly and safely, the chuck must run true. It is easy to break a drill when it wabbles.
Most drills are made on the twist pattern, and it is something of a trick to grind a twist drill, but anyone can do it if he tackles the job with a determination to do it right. In grinding a twist drill, use a new drill for pattern. Grind the angles the same as the new drill, and be careful to have the point in the center. A little practice will make perfect.
Mechanics will say that no one except an expert should attempt to grind a twist drill, but farmers who are mechanically inclined are the best experts within reach. It is up to a farmer to grind his own drills or use them dull.
In drilling wrought iron either water or oil is required to cool the drill, but cast iron and brass are drilled dry. Light work such as hoop-iron may be drilled dry, but the cutting edge of the drill will last longer even in light work if the drill is fed with oil or water.
Figure 50.—(1) Electric Drill-Press. A small electric motor is attached to the drill spindle. (2) Tram Points. Two steel points are fitted with thumbscrew clamps to fasten them to a long wooden bar. They are used to scribe circles too large for the compasses. (3) Ratchet-Brace. Two braces, or bitstocks, are needed. A large brace with a 6″ radius for large bits and a small brace with a 3″ or 31⁄2″ radius for small bits.
In using drill-presses, some extra attachments come in very handy, such as a screw clamp to hold short pieces of metal. Before starting the drill, a center punch is used to mark the center of the hole to be bored and to start the drill in the right spot.
Figure 51.—Twist-Drills. Round shank for the post drill and square taper shank for brace work. Brace drills are small, 1⁄4″ or less.
Figure 52.—Taper Reamer. Used to enlarge, or true, or taper a hole that has been drilled or punched.
Figure 54.—Countersink. This is the old style, blacksmith-made, flat countersink. It will do quick work but not so smooth as the fluted kind.
In doing particular work, the drill may be re-centered when it starts wrong. This is done with a small round-nosed cold chisel. If the work is not very particular, the drill may be turned a little to one side by slanting the piece to be drilled. This plan is only a makeshift, however, the proper way being to block the work level, so that the drill will meet it perpendicularly. However, by starting carefully, the hole may be bored exactly as required.
Iron Working Tools.—Forge tools for a farm shop need not be numerous. Several pairs of tongs, one blacksmith hammer, one sledge, one hardy, one wooden-handled cold chisel, one pair pincers, one paring knife, one shoeing rasp, and one shoeing hammer will do to begin with.
Figure 55.—Machinist’s Hammers. A medium weight should be selected for farm repair work. It should be hung so the end of the handle clears half an inch when the face rests flat on the bench.
Monkey-wrenches come first in the wrench department. The farmer needs three sizes, one may be quite small, say six inches in length, one ten inches, and the other large enough to span a two-inch nut. And there should be an ironclad rule, never use a monkey-wrench for a hammer. For work around plows, cultivators, harvesters, and other farm machines, a case of S wrenches will be greatly appreciated. Manufacturers include wrenches with almost all farm machines, but such wrenches are too cheap to be of much use.
Figure 56.—(1) Hardy. The anvil hardy is used more than any other anvil tool except the blacksmith’s hammer and tongs. (2) A Cold-Shut Link that may be welded, riveted or simply pounded shut.
Figure 57.—Calipers: (1) A pair of tight-joint inside calipers. (2) Its mate for taking outside dimensions. (3) A pair of spring-jointed, screw-adjustment inside calipers for machinists’ use.
Figure 58.—Blacksmith Tongs. Straight tongs made to hold 3⁄8″ iron is the handiest size. Two or three pairs for larger sizes of iron and one pair smaller come in handy.
Figure 59.—(1) Wire Splicer. The oval openings in the tool are of different sizes. They are made to hold two wires, close together, with ends projecting in opposite directions. Each end is wound around the other wire. The ends are then notched with a three-cornered file and broken off short and filed smooth. The splicing tool should be thin, about 1⁄8″ or 3⁄16″, to bring the two twists close together. This is especially necessary in making hoops for wooden pails. (2) Blacksmith Shoeing Pincers, used to pull horseshoes. They should close together to catch a nail by the head.
For heavier work pipe-wrenches are absolutely necessary. The reason for having so many wrenches is to save time when in the field. It often happens that men and horses stand idle waiting for what should be a quick repair job.
Figure 60.—(1) Cotter Pin Tool. Handy for inserting or removing all sorts of cotter keys. (2) Nest of S Wrenches of different sizes. Farmers have never appreciated the value of light, handy wrenches to fit all sorts of nuts and bolt heads closely.
For bench work a riveting hammer and a ball peen machinist’s hammer are needed. A nest of S wrenches, two rivet sets, cold chisels, round punches and several files also are required.
The same twist drills up to three-eighths-inch will do for iron as well as wood. However, if much drilling is done, then round shank twist drills to fit the drill chuck will work better. Farmers seldom drill holes in iron larger than one-half inch. For particular work, to get the exact size, reamers are used to finish the holes after drilling. Screw holes in iron are countersunk in the drill-press.
Figure 61.—Hack Saw. One handle and a dozen blades. The frame should be stiff enough either to push or pull the saw without binding. The teeth may point either way to suit the work in hand.
For small work, twist drills with square shanks for brace use should range in sizes from one thirty-second of an inch up to one-quarter inch, then every one-sixteenth inch up to one-half inch.
For boring screw holes in wood the quickest work is done with pod bits. Not many sizes are needed, but they are cheap, so that a half dozen, ranging from one-sixteenth to one-quarter inch or thereabouts, will be found very useful. Pod bits belong to the wood department, but on account of being used principally for screw sinking, they are just as useful in the iron working department as in the carpenter shop.
Sheet metal snips for cutting sheet metal properly belong with the iron working tools. Snips are from ten to fourteen inches in length. A medium size is best for miscellaneous work. If kept in good working order twelve-inch snips will cut 18-gauge galvanized or black iron. But a man would not care to do a great deal of such heavy cutting.
Figure 63.—Cutting Nippers. For cutting the points from horseshoe nails after they are driven through the hoof to hold the shoe in place. These nippers are hard tempered and should not be used for any other purpose.
Pipe-Fitting Tools.—Recent farm improvements require a few tools that rightfully belong to plumbers. Every farm has some kind of water supply for domestic use and for live-stock. A great many farm machines require pipe tools for repair work. Every year more plumbing reaches the farm.
Plumbing work is no more difficult than other mechanical work, if the tools are at hand to meet the different requirements. One job of plumbing that used to stand out as an impossibility was the soldering together of lead pipes, technically termed “wiping a joint.” This operation has been discontinued. Every possible connection required in farm plumbing is now provided for in standardized fittings. Every pipe-fitting or connection that conducts supply water or waste water nowadays screws together. Sizes are all made to certain standards and the couplings are almost perfect, so that work formerly shrouded in mystery or hidden under trade secrets is now open to every schoolboy who has learned to read.
Figure 65.—(1) Pipe Vise. Hinged to open for long pipes. (2) Machinist’s Vise. Made with a turntable to take any horizontal angle. The pipe jaws are removable.
The necessary outfit to handle all the piping and plumbing on the farm is not very expensive, probably $25.00 will include every tool and all other appliances necessary to put in all the piping needed to carry water to the watering troughs and to supply hot and cold water to the kitchen and the bathroom, together with the waste pipes, ventilators and the sewer to the septic tank. The same outfit of tools will answer for repair work for a lifetime.
Farm water pipes usually are small. There may be a two-inch suction pipe to the force pump, and the discharge may be one and a half inch. But these pipes are not likely to make trouble.
Figure 66.—Pipe Cutter. The most satisfactory pipe cutter has three knife-edge roller cutters which follow each other around the pipe. Some of these cutters have two flat face rollers and one cutter roller to prevent raising a burr on the end of the pipe. The flat face rollers iron out the burr and leave the freshly cut pipe the same size clear to the end.
Figure 67.—Pipe-Wrench. This type of wrench is valuable for working with the heavier farm implements. It is intended more for holding than for turning. It is rather rough on nuts. Damaged nuts show signs of careless work.
There should be a good pipe vise that will hold any size pipe up to three inches. At least two pipe wrenches are needed and they should be adjustable from one-quarter-inch up to two-inch pipe.
We must remember that water pipe sizes mean inside measurements. One-inch pipe is about one and one-quarter inches outside diameter. Three-quarter-inch pipe is about one inch outside. Two-inch pipe will carry four times as much water as one-inch pipe, under the rule “doubling the diameter increases the capacity four times.”
The three-wheel pipe cutter works quickly and is satisfactory for most jobs. Sometimes two of the knife wheels are removed and rollers substituted to prevent raising a burr on the end of the pipe.
Threading dies are made in standard sizes. A good farm set consists of stock and dies to thread all the different sizes of pipe from one-quarter inch to one inch, inclusive. Not many pipes larger than inch are threaded on the farm. They are cut to the proper lengths in the farm shop and the threads are cut in town.
Each farmer must be the judge in regard to the kind of mechanical repair work that should be done at home and the kind and amount of repair work that should go to the shop in town. A great deal depends on the mechanical ability of the farmer or his helpers. However, the poorest farm mechanic can do “first aid” service to farm implements and machinery in the nick of time, if he is so disposed. A great many farmers are helpless in this respect because they want to be helpless. It is so much easier to let it go than to go right at it with a determination to fix it, and fix it right.
Figure 69.—Logging Chain. One of the cleverest farm inventions of any age is the logging chain. It is universally used in all lumber camps and on every farm. It usually is from 16 to 20 feet in length, with a round hook on one end for the slip hitch and a grab hook on the other end that makes fast between any two links.
Figure 70.—Neckyoke and Whiffletree Irons. Farmers can make better neckyokes and whiffletrees than they can buy ready-made. The irons may be bought separately and the wood selected piece by piece.
Figure 71.—Measuring a Worn Skein for a New Boxing. The pasteboard calipers are cut to fit the old skein sideways because it is probably flattened on the bottom from wear.
On general principles, however, farm repair work should not occupy a farmer’s time to the detriment of growing crops or the proper care of live-stock. Farming is the business; mechanical work is a side issue. At the same time, a farmer so inclined can find time during the year to look over every farm machine, every implement and every hand tool on the farm. The stupidest farm helper can clean the rust off of a spade and rub the surface with an oily cloth, in which some fine emery has been dusted. The emery will remove the rust and the oil will prevent it from further rusting. Every laborer knows better than to use a spade or shovel after a rivet head has given way so the handle is not properly supported by the plate extensions. There really is no excuse for using tools or machinery that are out of repair, but the extent to which a farmer can profitably do his own repairing depends on many contingencies. In every case he must decide according to circumstances, always, however, with a desire and determination to run his farm on business principles.
Figure 72.—Wooden Wagon Axles. Axle timber may be bought in the rough or partly fitted to the skeins.
Figure 74.—Wire Splice. With a little practice wire may be wound close enough to prevent slipping.
Home-made Bolts.—The easiest way to make a bolt is to cut a rod of round iron the proper length and run a thread on each end. On one end the thread may be just long enough to rivet the head, while the thread on the other end is made longer to accommodate the nut and to take up slack. A farmer needs round iron in sizes from one-fourth inch to five-eighths inch. He will use more three-eighths and one-half inch than any other sizes. Blank nuts are made in standard sizes to fit any size of round iron. Have an assortment, in different sizes, of both the square and the hexagon nuts.
Figure 75.—Emergency Bolts. A bolt may be made quickly without a forge fire by cutting a short thread on one end for the head and a longer thread on the other end for the nut.
Figure 76.—Rivets. A stock of soft iron rivets of different sizes and lengths should be always kept on hand ready for immediate use.
To make a bolt in the ordinary way requires welding, but for repair work in a hurry it is better to select the proper iron and cut it to the required length either with a cold chisel in the vise, or with a hardy and a handled cold chisel over an anvil. The quickest way of cutting that mashes the rod the least is to be preferred. The size of the rod will determine the manner of cutting in most instances.
Figure 78.—Rivet Set. This style of set is used for small rivets. The size should be selected to fit the rivets closely. Larger rivets are made to hug the work by means of a flat piece of steel with a hole through it.
Figure 80.—(1) Coulter Clamp. Plow-beam clamps should be made in the farm shop to fit each plow. (2) Garden Weeder. The quickest hand killer of young weeds in the garden is a flat steel blade that works horizontally half an inch below the surface of the ground.
Figure 81.—Stock and Dies. Taps and dies and stocks are best kept in compartments in a case made for the purpose.
Figure 82.—Stock for Round Dies. The opening is turned true and sized accurately to fit. The screw applies pressure to hold the die by friction.
Figure 83.—Taps and Dies. Standard threads are tapped into blank nuts and corresponding threads are cut onto bolts with accuracy and rapidity by using this style taps and dies. They may be had in all sizes. The range for farm work should cut from 1⁄4″ to 5⁄8″, inclusive.
Figure 85.—Machine Bolt and Carriage Bolt. The first is used against iron and the second against wood, but this rule is not arbitrary. The rounded side of the nuts are turned in against wood; the flat side against washers or heavier iron. Use square head bolts if you expect to take them out after the nuts have rusted on.
Figure 86.—Plow bolts and sickle bar bolts should be kept in stock. Standard sizes and shapes are made for several different makes of plows and machines.
Taps and dies are made to fit each size of rod. If the thread on the bolt is cut with a solid, or round, plate die, the corresponding tap is run clear through the nut. In that case the nut will screw on the bolt easily, possibly a little loose for some purposes. It is so intended by the manufacturers to give the workman a little leeway. If it is desirable to have the nut screw on the bolt very tight, then the tap is stopped before the last thread enters the nut. A little practice soon qualifies a workman to fit a nut according to the place the bolt is to occupy.
Figure 87.—Lag Screw. To set a lag screw in hardwood, bore a hole the size of the screw shank as calipered between the threads.
Figure 88.—(1) Wagon-Box Irons, showing how to attach the box and the rave to the cross-piece and to brace the side of the box to hold it upright. There may be several of these braces on each side of the wagon box. (2) U Bolt in Cement. A solid staple to be embedded in concrete for a horse ring, door hinge, cow stanchion, etc.
Generally it is desirable to have nuts fit very snug on parts of machines that shake a good deal, and this applies to almost all farm machinery and implements.
Figure 89.—Wagon-Box Brace. It is offset to hold the rave and to brace the sideboard at the rear and the front ends and sometimes in the middle of light wagon beds.
Ordinarily a horse rake is supposed to travel steadily along like a cart, but the ground is rough and in practical use the nuts loosen almost as soon as haying commences.
Some farmers make a practice of riveting bolt ends to prevent nuts from working loose. When the bolts have square heads, this practice is not objectionable, because with two wrenches a nut can be twisted off over the riveting, but a great many bolts have round heads and very short, square shanks. Theoretically, the shanks are driven into the wood firm enough to prevent the bolts from turning. Practically this theory is a delusion and a snare, as every farm boy can testify.
Bolts are not manufactured in quantities in the farm blacksmith shop. They can be made by machinery cheaper, but so many times a bolt is needed on short notice that the farm shop should have the necessary tools and materials to supply the need quickly.
Forging Iron and Steel.—Iron and steel are composed of the same properties, but differ chemically. Steel also is finer grained than iron and it requires different treatment. Iron should be forged at a light-red or white heat. If forged at a dark-red heat the iron generally will granulate or crack open and weaken the metal. For a smooth finish the last forging may be done at a dark-red heat, but the hammer must be used lightly. The weight of the hammer as well as the blows also must differ with the different size of iron under heat. Small sizes should be treated with hammer blows that are rather light, while for large sizes the blows should be correspondingly heavy. If light blows be given with a light hammer in forging heavy iron the outside alone will be affected, thus causing uneven tension and contrarywise strain in the iron.
Steel should never be heated above a yellow heat. If heated to a white heat the steel will be burned. Steel should never be forged at a dark-red heat. If this is done it will cause considerable strain between the inner and outer portions, which may cause it to crack while forging. The weight of the hammer and the hammer blows in forging of steel is vastly of more importance than in forging iron. If the blow or the hammer is not heavy enough to exert its force throughout the thickness of the steel it will probably crack in the process of hardening or tempering. If steel be properly forged it will harden easily and naturally, but if improperly forged the tempering will be very difficult—probably a failure. The quality of a finished tool depends greatly upon the correct heat and proper method used in forging and hardening it.
Making Steel Tools.—Steel for tools should first be annealed to even the density and prevent warping. This is done by heating it to a dull cherry red in a slow fire. A charcoal fire for this purpose is best because it contains no sulphur or other injurious impurities. After heating the piece of new steel all over as evenly as possible it should be buried several inches deep in powdered charcoal and left to cool. This completes the annealing process. While working steel into proper shape for tools, great care is required to prevent burning. It should be worked quickly and the process repeated as often as necessary. Practice is the only recipe for speed.
When the tool is shaped as well as possible on the anvil it is then finished with a file by clamping the new tool in the vise, using single cut files. Bastard files are too rough for tool steel. After the tool is shaped by cross-filing and draw-filing to make it smooth it is sometimes polished by wrapping fine emery cloth around the file. Oil is used with emery cloth to give the steel a luster finish. Tempering is the last process in the making of such tools as cold chisels, drills, dies, punches, scratchawls, etc.
Figure 91.—Blacksmith Hammers. Some smiths use a heavy machinist’s hammer. But the flat peen is more useful when working around the anvil and the leg vise.
Tempering Steel Tools.—Good judgment is required to get the right temper. Good eyesight is needed to catch the color at the exact instant, and quick action to plunge it into the water before it cools too much. Dies are made very hard. The color of the steel at dipping time should be a bright straw color. Cold chisels will break when being used if tempered too hard. If cold chisels are to be used for cutting iron, the color should be violet; if the chisels are for cutting stone, purple is the color. Drills for boring iron are tempered a dark straw color at the cutting edge merging back into blue. The water in the dipping tub should be warm, as steel is likely to check or crack when it is tempered in cold water.
Tool steel should be held in a perpendicular position when it enters the water to cool all sides alike. Otherwise the new tool might warp. It is better to dip slowly, sometimes holding the point, or cutting edge, in the water while permitting the shank to cool slowly enough to remain soft. Some sizes of steel may be tempered too hard at first and the temper immediately drawn by permitting the heat of the shank to follow down almost to the edge, then dip. This is done quickly while watching the colors as they move towards the point or edge.
Draw-filing.—Making six-sided and eight-sided punches and scratchawls out of hexagon and octagon tool steel is interesting work. The steel is cut to length by filing a crease all around with a three-cornered file. When it is sufficiently notched, the steel will break straight across. To shape the tool and to draw out the point the steel is heated in the forge to a dull cherry red and hammered carefully to preserve the shape along the taper. Special attention must be given to the numerous corners. A scratchawl or small punch, must be heated many times and hammered quickly before cooling. An old English shop adage reads: “Only one blacksmith ever went to the devil and that was for pounding cold iron.”
After the punch or scratchawl is roughed out on the anvil, it is fastened in the vise and finished by cross-filing and draw-filing. Copper caps on the vise jaws will prevent indentations.
Figure 92.—Vise Jaw Guards. Soft auxiliary vise jaws are made of sheet copper or galvanized iron.
Figure 93.—Roll Filing. To file a piece of steel round it is rolled by one hand while the file is used by the other hand.
Draw-filing means grasping each end of the file and moving it back and forth sidewise along the work. For this purpose single-cut files are used. The smoothing is done with a very fine single-cut file, or if very particular, a float file is used. Then the polish is rubbed on with fine emery cloth and oil. The emery cloth is wrapped around the file and the same motion is continued. With some little practice a very creditable piece of work may be turned out. Such work is valuable because of the instruction. A good test of skill at blacksmithing is making an octagon punch that tapers true to the eye when finished.
Set-Screws.—It is customary to fasten a good many gear wheels, cranks and pulleys to machinery shafts by set-screws. There are two kinds of set-screws; one has a cone point, the other a cup end. Both screws are hardened to sink into the shaft. A cup is supposed to cut a ring and the point is supposed to sink into the shaft to make a small hole sufficient to keep the wheel from slipping. However, unless the cone-pointed screw is countersunk into the shaft, it will not hold much of a strain. The point is so small it will slip and cut a groove around the shaft. To prevent this, the set-screw may be countersunk by first marking the shaft with an indentation of the point of the screw. Then the wheel or crank or collar may be removed and a hole drilled into the shaft with a twist-drill the same size, or a sixty-fourth smaller, than the set-screw. Then by forcing the end of the set-screw into the drill hole, the wheel is held solid.
Figure 94.—Machine-Bolt and Set-Screw. The bolt to the left is used to clamp cylinder heads in place. The set-screw to the right is the cup variety. The end is countersunk to form a cup with a sharp rim.
The principal objection to set-screws is that they are dangerous. The heads always project and are ready to catch a coat sleeve when the shaft is revolving. In all cases, set-screws should be as large as the hub will allow, and it is better to have them protected so it is impossible to catch anything to wind around the shaft. Cup set-screws are not satisfactory except for very light work. If necessary to use them, the ends may be firmly fixed by cutting a ring with a sharp, diamond-point cold chisel.
Setting the Handsaw.—Nine teeth to the inch is the most satisfactory handsaw for all kinds of lumber. Setting the teeth of this kind of saw is best done with a hand lever set. The plunger pin should be carefully adjusted to bend the teeth just far enough to give the necessary set. For general work a saw needs more set than is needed for kiln-dried stuff. The teeth should cut a kerf just wide enough to clear the blade. Anything more is a waste of time and muscle. It is better to work from both sides of the saw by first setting one side the whole length of the blade. Then reverse the saw in the clamp and set the alternate teeth in the same manner. There should be a good solid stop between the handles of the set to insure equal pressure against each sawtooth. The pin should be carefully placed against each tooth at exactly the same spot every time and the pressure should be the same for each tooth.
The best saw-sets for fine tooth saws are automatic so far as it is possible to make them so, but the skill of the operator determines the quality of the work. The reason for setting a saw before jointing is to leave the flattened ends of the teeth square with the blade after the jointing and filing is completed.
Jointing a Handsaw.—After the saw has been set it must be jointed to square the teeth and to even them to equal length, and to keep the saw straight on the cutting edge. Some woodworkers give their saws a slight camber, or belly, to correspond with the sway-back. The camber facilitates cutting to the bottom in mitre-box work without sawing into the bed piece of the box. It also throws the greatest weight of the thrust upon the middle teeth. A saw with even teeth cuts smoother, runs truer and works faster than a saw filed by guess. It is easy to file a saw when all of the teeth are the same length and all have the same set. Anyone can do a good job of filing if the saw is made right to begin with, but no one can put a saw in good working order with a three-cornered file as his only tool.
Figure 95.—Saw Jointer. The wooden block is about two inches square by 12″ or 14″ in length. The block is made true and scribed carefully to have the ripsaw slot square, straight and true. The file is set into a mortise square with the block.
Filing the Handsaw.—First comes the three-cornered file. It should be just large enough to do the work. There is no economy in buying larger files thinking that each of the three corners will answer the same purpose as a whole file of smaller size. In the first place the small file is better controlled and will do better work. In the second place the three corners are needed to gum the bottoms of the divisions between the teeth. There is much more wear on the corners than on the sides of a saw-file. Also the corners of a small file are more acute, which means a good deal in the shape of the finished teeth.
After the saw is carefully set and jointed, clamp it in the saw vise and file one side of the saw from heel to point. Then reverse the saw in the saw clamp and file the other side, being careful to keep the bevel of each tooth the same. It is better to stop filing just before the tooth comes to a point. A triangular or diamond shaped point will cut faster and leave a smoother saw kerf and last longer than a needle point.
As the tooth of a crosscut saw is filed away from both edges, it is necessary to make allowances when filing the first side, otherwise some of the teeth will come to a sharp point before the gumming is deep enough.
Using a Handsaw.—Anyone can saw a board square both up and down and crossways by following a few simple rules. Have the board supported on the level by two well made saw-benches 24″ high. Stand up straight as possible and look down on both sides of the saw blade. Use long even strokes and let the saw play lightly and evenly through the saw cut.
Do not cut the mark out; cut to it on the waste end, or further end, if there are more pieces to be cut from the board. The saw kerf is about 3⁄32″ wide for a nine-tooth saw set for unkilned lumber or dimension stuff. If both saw kerfs are taken from one piece and none from the next then one length will be 3⁄16″ shorter than the other.
For practice it is a good plan to make two marks 3⁄32″ apart and cut between them. Use a sharp-pointed scratchawl to make the marks. A penknife blade is next best, but it must be held flat against the blade of the square, otherwise it will crowd in or run off at a tangent.
Setting a Circular Saw.—A good saw-set for a circular saw may be made out of an old worn-out flat file. Heat the file in the forge fire to draw the temper and anneal it by covering it with ashes. Smooth it on the grindstone. Put it in the vise and file a notch in one edge. The notch should be just wide enough to fit loosely over the point of a sawtooth. The notch should be just deep enough to reach down one-quarter of the length of the tooth.
Make a saw-set gauge out of a piece of flat iron or steel one inch wide and about four inches long. File a notch into and parallel to one edge at one corner, about one-sixteenth of an inch deep from the edge and about half an inch long measuring from the end. With the home-made saw-set bend the saw teeth outward until the points just miss the iron gauge in the corner notch. The edges of the gauge should be straight and parallel and the notch should be parallel with the edge. In use the edge of the gauge is laid against the side of the saw so the projecting tooth reaches into the notch. One-sixteenth of an inch may be too much set for a small saw but it won’t be too much for a 24-inch wood saw working in green cord wood.
Jointing a Circular Saw.—Run the saw at full speed. Lay a 14-inch file flat on the top of the saw table at right angles to the saw. Move the file slowly and carefully towards the saw until it ticks against the teeth. Hold the file firmly by both ends until each sawtooth ticks lightly against the file. A saw in good working order needs very little jointing, but it should have attention every time the saw is set and it should be done after setting and before filing.
Filing a Circular Saw.—The teeth of a crosscut circular saw point a little ahead. Sometimes they point so nearly straight out from the center that you have to look twice to determine which way the saw should run. There are plenty of rules for the pitch of sawteeth, but they are subject to many qualifications. What interests a farmer is a saw that will cut green poles and crooked limbs into stove lengths with the least possible delay. A saw 20 inches in diameter will cut a stick eight inches through without turning it to finish the cut. The front or cutting edges of the teeth of a 24-inch crosscut circular saw for wood sawing should line to a point a little back from the center. This may not sound definite enough for best results, so the more particular farmers may use a straight edge. Select a straight stick about half an inch square. Rest it on top of or against the back of the saw mandrel and shape the forward edges of the teeth on a line with the upper side or rear side of the straight edge. The teeth will stand at the proper pitch when the saw is new, if it was designed for sawing green wood. If it works right before being filed, then the width of the straight edge may be made to conform to the original pitch and kept for future use.
The gumming is done with the edge of the file while filing the front edges of the teeth. It is finished with the flat side of the file while filing the rear edges of the teeth. The depth, or length, of the teeth should be kept the same as the manufacturer designed them. A wood saw works best when the front edges of the teeth have but little bevel. The back edges should have more slant. The teeth should have three-cornered or diamond-shaped points. Needle points break off when they come against knots or cross-grained hardwood. Short teeth do no cutting. Single cut flat files are used for circular saws. The file should fit the saw. It should be about 1⁄8″ wider than the length of the front side of the teeth. The back edges require that the file shall have some play to show part of the tooth while the file is in motion. Large files are clumsy. The file should be carefully selected.