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Metalwork for Craftsmen
A Step by Step Guide with 55 Projects
By Emil F. Kronquist
Dover Publications, Inc.Copyright © 1972 Dover Publications, Inc.
All rights reserved.
LABOR — REWARD
There is a perennial nobleness, and even sacredness, in work. Were he never so benighted, forgetful of his high calling, there is always hope in a man that actually and earnestly works; in idleness alone is there despair. — A man perfects himself by working, foul jungles are cleared away, fair seedfields rise instead, and stately cities. — Consider how, even in the meanest sorts of labor, the whole soul of a man is composed into a kind of real harmony, the instant he sets himself to work. — Blessed is he who has found his work; let him ask no other blessedness. He has a work, a life purpose; he has found it, and will follow it. — Labor is life: From the inmost heart of the worker rises his God given force, the sacred celestial life essence breathed into him by Almighty God; from his inmost heart awakens him to all nobleness — — to all knowledge, "self-knowledge" and much else, so soon as work fitly begins. — Doubt, of whatever kind, can be ended by action alone.
— THOMAS CARLYLE (1795-1881).
TOOLS AND METALWORKING PROCESSES
TOOLS AND EQUIPMENT
Some of the common tools used by the metal craftworker are shown on the opposite page; others may be added as the need arises. Hammers and stakes are the most important tools and demand more attention and care than all others. The hammers should be of steel; the faces should be free from nicks and blemishes. The planishing hammers should have a mirror finish.
Tools Shown in Illustrations
1. Ball-peen hammer.
2. Sinking or plate hammer.
3. Raising hammer.
4. Planishing hammer.
5. Chasing hammer, also used for planishing.
6. Rawhide mallet.
7. Ball or mushroom stake.
8. Raising stake.
9. Bick iron stake.
10. Loose head for bick iron.
11. Bottom stake.
12. Jeweler's saw.
13. Hack saw.
14. Shears or snips.
15. Try square.
16. Cutting pliers.
17. Flatnose pliers.
18. Hand drill.
19. Bunsen burner.
21. Bench vise.
CUTTING OF STOCK
The cutting of stock for the execution of a job sometimes requires a good deal of preparatory work, such as the making of patterns or templates, the selecting of materials and gauges of metal to be used, and figuring the length of wire. This preparation is made in order to have the least possible waste of material.
Sometimes the stock must be cut with a slight allowance for cleaning off. This waste margin, of course, should not be too wide. Just sufficient metal should be left so that the raw cutting edge can be filed smooth.
Cutting with Shears
For general work a pair of straight shears 12 inches long is most useful (Fig. 1). For cutting heavier gauge metal the shears can be fastened in the vise, as shown in Fig. 2. The metal is cut with greater ease when the shears are held at a slight angle, as shown in Fig. 3.
Cutting with Hack Saw
The hack saw is used for cutting wire rods or tubing (Fig. 4). The blade is made of hard steel and breaks easily when given a sudden jerk or twist. A saw blade with 32 teeth per inch is best suited for craftwork and should be replaced whenever it becomes dull. A pair of false jaws for the vise (Fig. 7) should be used to protect the material from unnecessary marring. Most hack saws are made so that the blade can be swiveled at right angles or upside down.
Cutting with Jeweler's Saw
This is one of the most useful tools of the craftworker. Although it is made in many depths, a 5-inch saw is recommended. The blades are purchased in bundles, by the gross, or by the dozen lot; for general work a No. 2 blade is best. The blade is placed in the frame with the teeth pointing toward the handle; it works on the down stroke (Fig. 5).
Other methods of cutting heavy gauge metal with a chisel, hammer, and saw are shown in Figs. 6, 8, and 9.
ANNEALING AND HEATING
Annealing is the name given to the process of softening metal by means of heating.
During the working and shaping, metal becomes hard, either by compression or by tension, and annealing has to be resorted to before any further shaping can be done. Annealing reduces the hardness and removes the strains that have been induced in the material by some previous treatment.
Without annealing, it would be impossible for the craftsman to fashion some pieces of work; therefore, heating becomes a matter of extreme importance.
Annealing with a Torch
Adjust the air and the gas until a blue flame appears. Move the flame slowly over the entire metal surface until it is uniformly red (Fig. 1).
Annealing Small Pieces over a Bunsen Burner
Hold the metal at a corner with a pair of pliers (Fig. 2). The point of the inner air cone of the flame is the hottest (Fig. 3).
Annealing with a Mouth Blowpipe and Alcohol Lamp
A little practice is required in order to produce an even blue flame (Fig. 4).
Annealing of Wire
Coil the wire in a tight bundle: move a soft flame to and fro over it until it becomes red.
Move the flame slowly over the surface; touch the metal with a stick of wood (match). If the metal scorches the wood, it is hot enough. Experiment with a scrap of aluminum.
Softening of Pewter
Move a soft flame (no air) over the metal surface; moisten a finger and touch the metal at different spots, listening for a sizzling of the moisture.
Overheating may cause the metal to melt.
Spotty heating should be avoided.
Alloyed metals should not be picked up while they are red hot.
Small size wire cannot be annealed safely in single strands.
Aluminum stays white; no pickling is necessary.
PICKLING OF METALS
Pickling is the term used by metalworkers when an object is plunged, dipped, suspended, or boiled in some kind of acid solution for the purpose of removing or dissolving the oxide or scale formed on the metal in the process of annealing.
The pickling of metals is an essential part of the work of the craftsman. It would be difficult to see any of the blows of the hammer or to do any kind of marking on the surface of the metal if the oxide were not removed. Scrubbing with an abrasive, such as kitchen cleanser or pumice powder, would take too long and would not accomplish what acid does in a couple of minutes.
Iron tools, such as pliers, tongs, and tweezers, must be kept out of the acid.
Pickling Solution for Copper, Brass, and Silver
To 1 gallon of cold water, add about 6 ounces of commercial sulphuric acid (Fig. 1) and stir with a stick of wood. (Water should never be added to sulphuric acid, nor should sulphuric acid be added to boiling water, because steam is generated which causes a small explosion and may result in serious acid burns.)
Procedure to Be Followed When Pickling
1. Pick up the annealed metal with the pickup tongs (Fig. 3) or a pair of pliers.
2. Step back an arm's length and drop the metal, while hot, into the pickling bath.
3. Wait a minute or two for the oxide to dissolve, then pick it up with a stick of wood (Fig. 2). Rinse the metal thoroughly in running water.
4. Dry the metal with a clean rag or dry it in hardwood sawdust (Fig. 5).
Alloyed metals, such as brass, bronze, and nickel silver should be allowed to cool slightly before being thrown into the acid solution.
A hot pickling solution will dissolve the oxide and clean the metal quicker than a cold solution; it will also dissolve a borax flux (Fig. 4).
Sterling silver becomes pure white after boiling. The pickling solution dissolves the extracted deposit of oxide formed in the process of heating and leaves a coating of fine silver on the surface.
Several methods may be employed in hammering up a shallow piece of work. It is best to be guided by the shape of the design in choosing the method of execution and also by the available equipment. The most elementary way of making a small bowl is shown in successive steps on the opposite page. A ball-peen or hollowing hammer is used; also, a block of wood having a hollow depression on the end grain side. The metal disk is hammered along the outer edge first and continuing inward toward the center, the metal being stretched down into the hollow depression in the wood. The consequent thinning of the metal naturally limits the depth.
Procedure to Be Followed in Making
1. Cut the circular metal disk.
2. Draw a few concentric circles for guide lines.
3. Begin hammering along the outer edge, continuing in circular fashion until the center is reached. Avoid striking the edge of the metal (Fig. 1).
4. Anneal the metal. Pickle, if necessary.
5. Repeat the hammering until the desired depth has been reached. Anneal between each beating (Figs. 2, 3, 4, and 5).
6. Place the bowl on a mushroom stake and smooth the surface with a mallet (Fig. 6).
7. Anneal and clean the metal; then planish the entire surface, starting in the center (Fig. 7). (See Planishing.)
8. Trim the edge with a pair of shears (Fig. 8).
9. Flatten the bottom (Fig. 9).
10. True the bottom, making a slight cove (Fig. 10).
11. Finish the edge to any desired design (Fig. 11).
In estimating, the diameter of the metal disk needed for hollowing is approximately the largest diameter of the design, plus the height. This, however, varies with the material used and how the individual works.
Folds in the metal will lead to subsequent cracking.
A wavy top edge should be corrected as the work proceeds.
SHALLOW RAISING WITH WEDGE MALLET
This method of raising a shallow vessel differs from the hollowing process in that the metal disk is worked from the outside. It is a contracting process, rather than a stretching process. The metal disk may be crimped as shown in Fig. 1 before the actual raising is started, but it is not necessary.
The raising is done by placing the disk on a T stake as shown, or a mushroom stake may be used, then contracting the metal with a wedge-shaped mallet, working in circles from the center to the edge. This method of shaping a piece of work does not thin the metal as hollowing does. It is the professional way of executing a first-class job.
Procedure to Be Followed in Making
1. Cut the circular disk.
2. Draw a few concentric circles with a pencil compass for guide lines.
3. Place the metal disk on a stake, as shown in Fig. 2, and begin raising it with a wedge-shaped mallet. When the edge has been reached, the work will look as in Fig. 3.
4. Anneal the metal; pickle, if necessary.
5. Draw the guide lines and repeat the raising until the desired depth has been reached (Figs. 4, 5, and 6). The metal must be annealed after each raising.
6. Trim the edge with a pair of shears, as shown in Fig. 7.
7. Planish the work on a suitable shaped mushroom stake to remove all blemishes. Repeat, if necessary.
8. Flatten the bottom with a mallet (Fig. 8).
9. True up the bottom by making a shallow cove (Fig. 9).
10. Finish the edge to any desired shape.
The approximate diameter of the disk required is the largest diameter of the design, plus the over-all height.
The blows of the mallet should be delivered evenly.
Raising is the process of shaping a hollow vessel from a flat disk of sheet metal by using hammers and mallets and stakes (Figs. 1 and 2). The craftsmen of old were masters of the art of raising and it may still be regarded as a basic process.
Great height can be attained by careful and systematic hammering and annealing. The process differs from hollow and shallow raising in that the metal is worked almost entirely on the outside — a contracting operation, so to speak.
Procedure to Be Followed in Raising(Typical Example)
1. Cut a metal disk, the diameter of which should be approximately "the largest diameter plus the greatest height" of the design, 7 inches (Fig. 3).
2. Anneal the metal.
3. The raising may be started in either one of two ways: a. Doming up a shallow bowl (Fig. 4). b. Crimping the disk, as shown in Fig. 5. This may be done on a block of wood.
4. Anneal and pickle the metal.
5. Draw a circle on the outside of the bowl equal in diameter to that of the bottom of the design.
6. Place the work on the raising stake, as shown in Figs. 6 and 7. and begin hammering, going round and round, crowding a little metal upward toward the edge by each blow of the hammer. It is important to hold the metal against the nose of the stake in such a way that the hammer blow lands just above the point of contact. On the last round, along the edge, use a wood mallet.
7. Anneal and pickle the metal.
From this point on, it is a repetition of the processes described in Steps 6 and 7. The blows of the raising hammer must fall squarely on the metal and the work must be moved back on the stake as the edge is approached (Fig. 8).
Pencil guide lines must be described on the work at the beginning of each course of hammering.
Planishing is the process of making a metallic surface smooth by hammering lightly and producing, one might say, a texture. Only tools with a mirror-polished working surface should be used. Often the process is repeated several times before all blemishes and bruises from previous hammering have disappeared. To distribute the blows of the hammer evenly requires much patient practice. The arm should be kept close to the body and a wrist motion used in delivering the light blows of the hammer.
A mirror finish on a planishing hammer may be produced in the following manner:
1. Tack a sheet of emery cloth, No. 180 grit, on a board with four small nails, squirt plenty of oil on the emery, and rub back and forth until all rough marks have disappeared.
2. Tack a sheet of emery cloth, No. 280 grit, on another board, oil it, and rub the hammer back and forth until all the scratches produced by the coarser grit have disappeared.
3. Tack on third board a sheet of emery cloth, No. 360 grit, oil and rub as before. The steel is now ready for the final polish.
4. Tack a sheet of crocus cloth (rouge cloth) on a board, squirt plenty of oil on it, and rub the hammer until it shines like a mirror.
This polishing equipment should be wrapped up and stored for future use.
Procedure to Be Followed in Planishing
1. Clean the metal so that it is free from grease and oxides.
2. Select a stake or iron that has a curvature as near to that of the work as possible (Fig. 1).
3. Select a hammer of suitable weight and shape (Fig. 2).
4. Place the work on the stake.
5. Begin planishing. The fall of the hammer should be square on the work at the point of contact (Fig. 3).
The hammer blows should fall evenly, the work being rotated or moved so that no two blows fall in the same place.
Planishing should not alter the shape of the work; it should true it, close the granular texture, and remove irregularities from the surface. Planishing stretches the work slightly. Concentric pencil circles should be described on circular work to act as guide lines. Planishing may be repeated several times.
BENDING AND SHAPING METAL
Bending and shaping sheet metal and wire often must be done over specially prepared blocks of wood or iron. Devices called "jigs" sometimes are made when duplicate pieces have to be formed. Hand pressure should be employed whenever possible and, as a rule, is sufficient, at least when handling the lighter gauges of metal. A mallet or hammer is necessary when dealing with heavy-gauge metal or bar stock.
Metal should be annealed before any bending is attempted, and sometimes the metal must be reannealed before the final shape is reached.
Methods of Bending and Shaping Metal
1. Squeeze the metal between two pieces of wood or metal (Figs. 1 and 2).
2. Bend over specially prepared forms or around pieces of steel. Due allowance should be made for spring back when wire is bent (Fig. 3).
3. Shape with bending jigs such as are shown in Figs. 5 and 6. Scrolls should be started as shown in Fig. 4 and may be finished entirely with a hammer and various stakes.
4. Score with blunt chisel or chasing tool to secure a sharp bend. The tool must be blunt and the angle of the bevel should be approximately ninety degrees (Figs. 7 and 8). This scoring process requires considerable practice before it can be executed accurately.
5. Shape with a sheet-metalworker's brake.
Excerpted from Metalwork for Craftsmen by Emil F. Kronquist. Copyright © 1972 Dover Publications, Inc.. Excerpted by permission of Dover Publications, Inc..
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