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DECORATIVE WROUGHT IRONWORK
Projects for Beginners
By THOMAS F. GOOGERTY
Dover Publications, Inc.Copyright © 2005 Dover Publications, Inc.
All rights reserved.
Part I. Tools.
The tools described on the following pages are intended to supplement and not to take the place of the usual outfit of tools that constitutes a blacksmith's equipment. They are additional tools needed in making the objects described later in the book.
Rivet Set. One should have several rivet sets of different sizes, Fig. 1. They should be made from 3/8", ½", and 5/8" octagonal tool steel. They should be made in pairs—one long and one short-the long to fasten in a vise to hold the head of the rivet, and the short one to use in making the head on the other end of the rivet.
There should be larger rivet sets made with holes or eyes punched through them for a wooden handle. This kind of rivet set is used on large hot rivets. When one has use for a rivet set, it should be made and there should be a place in which to keep it with others.
To make the depression at the end of a rivet set, the end is heated and caught vertical in a vise. A punch is ground and filed smooth on the end to the shape of a rivet head. With this punch, a depression is hammered into the hot end of the steel to be used for the set. When the depression is completed, the sides of the set are ground within of the depression. The set is hardened and tempered in the same manner as a chisel. See page 19.
Steel Stamp. Fig. 2 shows a drawing for a steel stamp that may be used to stamp hot iron with the worker's initials. The stamp is made from ½" octagonal tool steel, 85-point carbon. To make the stamp is a very simple job. Cut the piece 4½" long and round up each end. Grind one end flat; then file it smooth. It is reheated and allowed to anneal. With a sharp red pencil, the initial is sketched on the end in reverse.
The letter is cut into the steel with a very narrow chasing chisel. When the letter is cut lightly and correct in shape, it is gone over with a blunter chisel until the line is quite heavy. It should be tested as one proceeds. Do this by hammering it into lead. When it is finished, the edges are made a little round. Then it is hardened and tempered.
When using, the stamp is held with a pair of tongs and struck with a hammer while the metal is hot. File a straight line across the stock to enable one to know when the letter is right-side up.
Vise Heading Tool for Rivets. Fig. 3 shows a rivet-heading tool to be used in the vise. The stock is ¾" square soft steel. The center of the bar is drawn flat; the stock should be made as wide as possible and about 3/10" thick. The center is to be formed into a ring as shown on the drawing. Before the prongs are closed together, the inside should be filed straight and smooth. It is then closed and the top filed. A piece of paper or tin is put in between the prongs and the whole is clamped tight. Holes are drilled along the crack from 3/32", for very small stock, to ¼" in size. The paper is taken out and the holes are casehardened.
To use the tool in heading rivets, short pieces of copper and iron are made round the size wanted. A piece of the stock is then put into the hole it fits. The tool is fastened in the vise. The end of the rivet bar is filed flat on the top, the right amount of stock being allowed for the head to project upward. With the hammer and rivet set, the head is made. It is well to make the ends of the prongs open a little to give the tool spring. The rivets when headed will come out more freely. The spring in the tool comes from the loop or eye.
Line Gauge. In chasing lines on the surface of metal with small chisels and other tools, it is important to make a drawing with pencil or scratch awl; then go over the lines with the chasing tools.
Fig. 4 shows a gauge for the purpose of marking lines on the edges of straight or curved forms. The guard is held against the edges, and moved along, scratching the line. The line can be made quite deep and be easy to follow with the chasing tool when cutting. The gauge can be made from a clock spring or any thin metal. There should be several sizes of the gauge.
Surface Plate. Fig. 5 shows a surface plate mounted on a wooden trestle. The plate is 18" x 28", made from cast iron, and is 3" deep. The underside is ribbed to lighten and strengthen it. The top is machined smooth. A surface plate is used to level work upon, and for a drafting board. Work can be layed out to the correct size with chalk marks on this plate and the iron fitted to the chalk marks. In a shop there should be small surface plates 12" x 12" for benchwork. They are very convenient. A surface plate 3" thick, cast without ribs, is very useful in hammering heavy pieces to straighten them.
Elm Block. When sheet metal is beaten up from one side to shape an ornament, it is called repoussé. We shall call it bumping up ornament on sheet metal.
Fig. 6 shows an elm wood block on which to bump metal. Elm is the best wood for this purpose. The block should be about 38" high and any diameter. Leaf forms or any kind of raised ornament are roughly raised on the elm block.
To do this, the metal is heated and, with a ball hammer of the proper size, the metal is forced into the block by hammering. If a large part of the metal is to be raised in dome shape, the sheet should be set over a hole in the block and hammered carefully to raise the metal.
Details on the metal are sharpened by hammering them up on lead with steel tools. Steel round rings of various sizes are also used on which to bump metal.
Special Tools. Special tools are required to do decorative work in iron. When one needs an extra tool to do some particular work, it should be made. Chasing tools of all shapes are required. The drawings of some of these tools are shown on Plate 1, also drawings of some line decorations that may be produced with them. One should make many tools with different shapes. Some of the tools should have a gauge or projection to guide them.
When chasing a line near the edge of a piece of metal it should be parallel to the edge of the metal. If the edge of the metal is straight, the line should be a straight line. Cutting a light line by hand requires some practice. The method used is to follow a carefully made drawing on the metal. A red lead pencil should be used to lay out curved lines, and a sharp steel scratch awl for straight lines. In chasing, a small short cold chisel is used. One of its corners is hammered into a line, Fig. 7, and then, leading the chisel toward the worker's eye, it is hammered lightly with a small broad-faced hammer. When leading the chisel, one must be sure that the forward corner of the chisel is directly over the line on the drawing. In this way, the tool can turn on curved lines. Also, one must watch the tool's forward point and not the hammer. After a line has been made, it is easy to keep the tool cutting into the line, and the line may be made as deep as is necessary.
The hot chasing tools shown on the drawing, Plate 1, are made out of ¾" and 7/8" square stock with a hole punched through the center for a wood handle. All of the tools are made of 85-point carbon steel. In use, the stock is heated and, with a helper holding it on the anvil, the hot chasing tool is set on the iron with the projection of the tool (if chasing a line parallel to an edge) against the edge as a gauge. The tool is struck with the hammer and at the same time it is kept moving.
The small tools, along with other rectangular and round punches, should be kept in a tin container with their working ends up.
Plate 2 shows the drawings for tools that are useful. The modeling hammers are used to hammer leaf form and ornament on sheet metal.
The veining tools are used to hammer ribs, pipes, and other parts of the leaf. The veining tool is fastened in the vise, the leaf set on it and, with the peen of the hammer, the metal is forced into the depression. The leaf may be turned to make curved forms while hammering. The tool, A, is used to set the rib on while hammering on each side to make the raised part higher and sharper. Many other tools may be made to work out leaf forms. They may be made to fit into the square hole of the anvil as well as in the vise.
The chasing hammer shown on Plate 2 is used to strike the tools. There should be hammers of various weights. The riveting hammers are used when riveting, also for other work. They should be made from square steel, ½", 5/8", and ¾" being used. They are simple to make; a hole is punched for the eye, the peen drawn out flat, and the hammer part turned round on a machine lathe.
The long hot chisel is used to trim off particles of hot metal; it is also used to split hot metal. This chisel may be made from an old file.
The drawing shows chisels, a diamond point and a round nose. There should be various sizes of these, also flat chisels. These tools should be kept in a tin container with the cutting part up. These tools are used for carving and cutting lines. Most of them should be made from 3/8" octagonal chisel steel. A small bench grinder with a fine wheel is used to sharpen them. An example of the use of these tools is shown at Fig. 38, a door knocker. If the diamond-point and the round-nose chisels are sharpened right, all kinds of lines can be cut. In sharpening tools of this kind the flat surfaces must be flat or the tool will not work well. When the tool is sharp, stick the point into the thumbnail; if the tool sticks it is sharp, if it slips it must be reground.CHAPTER 2
Part II. Notes and Cautions
The following simple notes on forge work will be of value to the beginner. To those who have had experience, they are not new. They are the outgrowth of notes made while working in metal and while teaching.
Hammering. The proper way to hold the hand hammer in forging is to catch the handle with the four fingers around it and the thumb projecting along the side and near the top part of the handle.
Hammering Iron. In drawing out iron or steel on the anvil, the piece should be placed across the anvil when receiving the blows, or at a right angle to the long way of the anvil. If the piece is hammered when it is diagonal with the long way of the anvil it will twist out of shape.
Using Tongs. When forging pieces that must be handled with tongs, always see that the tongs fit the piece nicely and, when convenient, a ring should be put on the end of reins to hold them. Do not put tongs in water while red hot, as this destroys the metal.
Flatting. Flatters and tools that are to be struck with a sledge hammer should not be used to draw iron except when absolutely necessary. The stock should be drawn out with hammer and sledge; use flatters and other tools to smooth with only.
Welding. In welding iron or steel, the fire should be thoroughly cleaned and plenty of well- burned coke used. Fresh coal should never come in contact with the parts to be united. The fire should never be allowed to spread and break out around the edges. It should be confined to the center. Coal, before it is put on fire, must be thoroughly wet. Never put wet coal on top of fire, but place it around the edges and gradually bring it to the center.
Flux. Iron and soft steel may be welded by using clean, white sand as a flux. Marble, heated red and cooled, may be pulverized and used as a flux. It should be put on just as the metal begins to take the welding heat. Borax and welding compound, also, are used for welding steel. Borax is used in brazing copper and iron.
Hardening Steel in Water. When water is used as a quenching bath for hardening steel, it should be heated just a little before the steel is cooled. Cooling steel in cold water will often cause it to check. Enough salt should be put into the water to make a strong brine bath for hardening.
Casehardening. The surface of wrought iron or soft steel can be carbonized and then made hard by heating and cooling in water. A simple way to caseharden is to heat the piece to be hardened, then roll or sprinkle it with cyanide of potassium, reheat and cool in water to harden. Cyanide and its fumes are poisonous.
Brazing Iron and Steel, also Copper. Iron and steel can be fastened together by brazing. In doing this, the ends are tapered or dovetailed together and bound with wire or a rivet to hold them in position. They are then placed in the fire and brought to a red heat. Some borax and spelter are put on and the heat is raised until the brass flows. The work is then taken out of the fire and let cool, then it is finished with a file or by grinding. Spelter is an alloy of copper and zinc, and may be purchased from dealers. Brass wire may also be used in brazing, and sometimes copper.
Copper may be brazed with spelter or silver solder in the same manner as iron. One should have a clean fire, well burned out-no smoke or green coal. Copper will stand considerable heat before it will melt, but not so much as iron. When the spelter flows, the work must be removed from the fire.
Welding Rings. In welding rings from flat, round, or square stock, the method used in determining the length to cut the piece is to find the inside diameter, then add the thickness of the stock used, and multiply by 3.1416, or 3[1/7]. To this amount is added the amount of stock used to make the weld. For example, a ring is required 1" in thickness and its inside measure is ten inches: Solution—10 x 1 x 3[1/7] = 11 x 3[1/7] = 34[44/7]. Add to this length enough stock to make the lap and weld. The amount needed depends on how well one can weld. Perhaps ½" longer is enough.
Tempering Springs. When the spring is made, it is held with a light pair of tongs. If it is very small, it is best to twist some wire around it; then catch the wire with the tongs. It is heated to a dark red and dipped into sperm oil, or equal parts of lard and tallow. When cool, it is held over the flame of the fire until the surplus oil blazes and burns off. This is repeated two or three times and allowed to cool off on a dry place on the forge.
Scratch Awl or Scriber. A scratch awl is a long piece of light, round, or square tool steel, with a tapering end. On the other end, a ring is made so it can be handled, also to hang it by. The tapered end should be hardened and tempered. A scratch awl is used to mark through a hole in metal onto another piece of metal where a hole is to be drilled, also to mark on the surface of metal.
Annealing Steel. The method of annealing steel is first to heat the piece to a red heat. It is then covered with warm, slacked lime so that the air will not come in contact with it until cool. A simple way to anneal, when in a hurry, is to heat the steel red and set it in a dry place on the forge until black. It is then plunged into water quickly and brought out. This operation is repeated until the piece is cool. Steel is also annealed by heating the piece red and setting it on the forge until cool. The slower steel is cooled, the softer it becomes. Wrought iron and mild steel forgings should always be annealed when used in work where there is danger of breaking. This relieves the strains due to forging.
Center Punch. A center punch is used to mark metal where it is to have a hole drilled, or at the point where it is to be bent. It is made from chisel steel. Small center punches are made from 5/16, 3/8", ½", and 5/8" octagonal stock of 80-point carbon steel. One end of the steel is drawn out tapering and round. It is ground to a very short bevel and given a sharp point. It is then hardened and tempered.
Hardening and Tempering. To harden and temper chasing tools, cold chisels, and other tools of this kind, after the tool is forged and before it is hardened, anneal it. Every forged tool should be annealed before hardening to relieve the strain due to forging.
To harden, heat to a dark red, cool the end in water, leaving the heat above the watermark. Brighten the steel with an emery stick or sandpaper. The heat in the tool will move toward the point or cutting edge. In doing so, temper color will appear on the bright part of the tool. These colors range from a pale straw to a very dark blue. The straw color indicates very hard; dark blue, quite soft. When the blue comes to the point of the tool, cool in water. The tool is now ready for use. The steel should be chisel steel, 80- or 85- point carbon. Never harden the top of a tool; that is to be struck with the hammer. The reason for not hardening this end is that, due to its hardness, particles of steel might fly and injure the worker.
Iron Lacquer. To make a liquid coating for covering iron and steel to prevent rust, a high- grade varnish is used. Cheap varnish will turn yellow and spoil the appearance of the work. The coating should dry flat.
The lacquer should be thin; if it is not, put in some more turpentine. If it does not dry flat, pour in some more wax.
It is applied to the bright iron with a soft cotton cloth or brush. This lacquer may be used on brass and copper also, if they are combined with iron.
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