Part 8

_The piece in place for firing:_ It is usually best to light the oven before you begin to place the enamel on the work to be fired. The furnace heats up in the meantime. Place the piece on the top ledge of the furnace close to the chimney. This is a good place to dry the moisture out of the enamel. If this is not done the steam generated by the moisture and the heat causes explosions, which in turn disturb the enamel surface and dislodge small particles of the enamel. When the steam has stopped rising from the enamel--which you can tell by holding the piece between you and the light--the moisture has dried out and the work can be put into the muffle by use of a long pair of muffle tongs. Extreme care must be taken when placing the piece to be fired into the furnace. The enamel is now very dry. The particles are no longer held together by the moisture and the least jar will dislodge them. The doors of the furnace are usually in two pieces, so that the upper half can be lifted away from time to time. One can look in and watch the process of melting. When the enamel is first put into the furnace and the heat begins to melt it, it rapidly changes colour. As it begins to melt it settles down and takes on a glassy, soft, smooth surface. At this point it is ready to take out. It is placed again on the top of this furnace, where it cools off slowly, otherwise the difference in expansion between the metal and the glass would cause the surface to crack. After one or two trials one easily recognizes the critical time when the enamel is well baked. These directions are only for enamelling flat surfaces. If one should wish to enamel both the inside and outside of a box lid rounded on the top and curved on the under side, a few large drops of gum arabic should be mixed with the enamel used for the under side. This prevents it from dropping off when in position for firing.

When the work has cooled off so that it can be handled, it will show a surface every part of which is covered, if carefully done. If not the black spots will appear. These are copper spots oxidized by the heat, and must be thoroughly scrubbed and scraped. The enamel edges around these spots must be scraped away, covered with enamel, and refired. If there are no spots shown, the work is ready for finishing. You will find on the upper edge of the enamel line a black line caused by the impurities in the enamel which rise to the top edge. Scrape this off with a fine file until it entirely disappears.

The copper, too, usually takes on beautiful colours during the heating process. Many like to leave the colours just as they happen to come by the heat, others prefer to polish the surface to bring out the real copper colours rather than the oxide colours. To clean the oxide off one must put the piece into a pickling bath made up of one part of sulphuric acid to eight parts of water. This softens the scum on the surface of the metal so that a soft rag dipped into any cleaning material like pumice stone will easily clean it off.

TWO METHODS OF ENAMELLING

_Cloisonné:_ In this work the design is done usually in coloured enamels, which are separated one from another by means of ribs of metal bent so as to follow the outlines of the design. These ribs are placed on the plaque, and a drop of solder here and there keeps them in place. The coloured enamels are filled in between these ribs and fired as before explained.

_Champlevé:_ In this method the partitions between one colour and another are formed by ridges of the base and not by separated ribs of metal. These ridges are made by driving the metal with chasing tools from the under side up and raising it above the surface. The spaces between these walls are filled in with enamel, and it is all fired as explained before.

The lid on the rose jar as shown in the group is an example of this kind of enamelling.

IMITATION PATINA (GREEN TINT ON COPPER)

The best method of obtaining a coating resembling patina is to immerse the article in a solution of nitrate of copper, and then to place it while still wet in a chamber containing an abundance of carbolic acid. In this case the development of the green incrustation may be observed from day to day. If after a week the object has not yet obtained the proper colour, it must be again dipped in the above solution, and this operation is repeated till the desired shade has been acquired. As the formation of this green colour proceeds in the same way as in the open air, but more rapidly, a handsome and permanent coating of green can be produced by this means.

CHEMICAL METAL COLOURING

_How to put a thin coating of colouring on the surface of metals by chemicals:_ A great variety of shades may be obtained simply through heat. The colours ordinarily produced on copper articles by means of heat come through the polishing. Any metal whose surface is highly polished will take on a number of different colours, beginning at a straw colour and changing to a dark straw, purple, dark blue, light blue, and steel or gray, by heating the piece to be coloured to a temperature of 630° F.

_Barium sulphide and water (a very good composition for colouring metal):_ Immerse object until it assumes desired tint from light brown to violet to black. Heat gently over bunsen flame until a rich deep violet appears. After it is cool rub with soft cloth.

_Patina imitation (a very good composition for the greening of copper):_

1 part sal. ammoniac, 3 parts cream tartar, 6 parts salt, 12 parts hot water, 2 parts nitrate of copper.

Saturate soft cloth and rub or sprinkle the solution on the copper. Let stand in the open air ten or twelve hours. Wash the colour off with clear cold water. Tone down to suit.

Another way of colouring metal.

Silver.

_To oxidize silver:_ The following is a solution commonly used for oxidizing silver:

Potassium sulphide, 5 grains, Water, 10 fluid ounces.

The variety known as liver or sulphur is generally used, and imparts a reddish brown colour to the silver, the colour being darker the darker the solution. It should be worked at 60 or 70 per cent. The stronger the solution the blacker the colour. If ammonium carbonate (20 grains) is added to the above formula and is worked hot, a black colour appears upon rubbing with a very fine wire brush. It takes on the colour of black lead.

_Colouring of brass:_

Copper sulphate, 2 ounces; Water, just sufficient to dissolve the copper sulphate; Ammonia, to neutralize and make slightly alkaline.

This will turn brass a very beautiful blue-black colour. Copper assumes a very beautiful tint from this solution.

_Cement for engravers:_ Melt best pitch in an iron pot and when completely liquid stir in a mixture composed of two thirds of raw pitch and one third plaster of paris. Make a lot of ten pounds. Add one half pound mutton tallow, boil and mix thoroughly. Should this be too soft, add plaster of paris until you get the desired hardness:

5 lbs. black raw pitch, 5 lbs. plaster of paris, 1-1/2 lbs. mutton tallow.

_To polish enamel:_ After rubbing it down with the corundum file, take a small rod of tin or pewter and after anointing it with fine Tripoli or rotten-stone, grind the surface of the enamel evenly with the tin or pewter rod. Next take a stick of lime wood and use that with the rotten-stone in the same way and finish with putty powder and stick covered with chamois skin.

_To unsolder a piece of work:_ Paint those joints which are not to be unsoldered with a mixture of clay water, to which add a little common salt. When dry, scrape the part to be unsoldered and paint it with borax. Now heat till solder melts, pick off with pliers or knock it off with a gentle tap. The borax adds flux, thus helping the solder to run at a melting temperature.

MACHINERY IN METAL WORK: DIE MAKING

Most of the jewellery that we see nowadays and also much of the metal work is made under presses or drop hammers. As was shown in the making of the mould for the round copper tray, the skill lies in the making of the design and the making of a mould to fit the design.

The description of the making of a match safe by means of die sinking will explain how all die work is done: The design for the match safe is made by the artist, who turns it over to the die sinker. He, in turn, chisels out of a steel block, about 7 ins. square, a depression in which the design fits. If the match safe has an embossed design, this is all chiselled out carefully with small chisels and filed up smoothly so that when a piece of soft lead is driven into the depression it will take the shape of the match safe as designed by the artist. The lead is so soft that it takes the print readily. This lead reproduction shows to the die sinker any imperfection in the die. The imperfections, if there are any, are smoothed down. The driving in of the lead into the depression is repeated from time to time, until the mould is the exact reproduction of the artist's design.

The die is now hardened by heating it red hot and cooling in water. When taken out of the water it is placed in the hammer or press. On the ram of the hammer is keyed, directly above this die, a square block of lead. When the hammer falls, the impact of the lead upon the impression produces a reproduction of the impression. This lead piece makes the top die. A piece of thin silver is placed in the steel die over the impression. If the ram is now dropped upon the silver plate it will force the plate into the impression and will stamp the design on the silver. One half of the match box is made in this way. When two of these are made, put together, and soldered, they make a whole match box. Thousands of match boxes would be made from this one die. That is the reason why this class of work can be sold so cheaply.

The principle explained here is used for the making of tea sets, dinner sets, etc. The same thing is true of the round wood mould you made to make the copper tray in. It can be used to make dozens of trays, all the same size and shape.

GLOSSARY

_Alloy:_ Base metal added to silver or gold for hardness or colour. Also any combination of different metals by fusion.

_Annealing:_ Softening metal by making it red-hot and cooling slowly; for steel, brass, copper, silver, cooling quickly in water.

_Backing:_ The coating of enamel on the back surface of box lids, to neutralize expanse and contraction, thus preventing top enamel from cracking.

_Basse-taille:_ Low cutting of metal beneath the line of the surface, used in enamelling. The drawing or modelling of the subject is given by the different depths of cutting.

_Beck iron:_ T-shaped anvil or stake used in hammer work. The arms of the T are long; one is round and slender, and tapering; the other has a flat upper surface.

_Bossing up:_ Beating out sheet metal in the back into rough forms required.

_Champlevé:_ A process of enamelling on metal in which the ground of the pattern is cut away with a chisel into a series of shallow troughs into which the enamel is melted, the surface being afterward ground smooth and polished.

_Chasing:_ Surface modelling of metal with hammer and punch or chasing tools.

_Cloisonné:_ An enclosing ribbon wire, which being soldered edgewise on a metal ground makes a trough into which enamel is melted, the ribbon making the division. Thus the design is separated.

_Collar:_ A ring made of stout leather filled with sand or some other soft material used to support the pitch block.

_Draw Plate:_ A flat plate of steel or iron with rows of graduated holes, used for drawing or reducing wire.

_Face Plate:_ A square thick iron plate with the surface perfectly smooth and level to test work on.

_Flux:_ Any material used to protect the surface of metal from oxidation when exposed to heat. Borax and water mixed, etc.

_Graver:_ A kind of small chisel used for cutting metal, or lines on surfaces.

_Mandrel:_ A rod of wood or iron of any section used either for coiling wire for chains or the making of rings. _Matt tool:_ A punch, flat and graduated on one end, used for making groined surfaces on metal.

_Pickle:_ Solutions of various acids in water used for removing the film of oxide and sulphide surface of metal. The acids used are nitric acid, hydrochloric acid, and sulphuric acid, about 8 to 1. This is strong enough for ordinary work.

_Pin:_ The hard wood peg fixed in the bench to hold work against to file and fit.

_Pitch block:_ Some iron blocks and wood blocks covered with pitch used as a support for metal in repoussé work or chasing.

_Planishing:_ Beating a plane or level surface to a sheet of metal by the use of a broad smooth-faced hammer on a stake or anvil. Also used to give smoothed face to a bowl or cup or other object in sheet metal.

_Repoussé:_ The method of beating out sheet metal from the back with hammer and punches.

_Sand bag:_ A flat circular or square bag of leather filled with sand used for bossing up metal upon.

_Scraper:_ A tool made from an old file by sharpening the point on a stone to a three-sided pyramid; used for scraping clear edges and surfaces to be soldered and for cleaning up work generally.

_Snarling iron:_ Long Z-shaped bar of iron fixed in a vise and used for bossing out the surface of vessels from the inside. They act by rebounding from the blow of the hammer near the end fixed in the vise.

_Tracer:_ A chisel-shaped punch used for cutting for any design or work that requires deep lines.

THE BLACKSMITH'S SHOP

XX

BLACKSMITHING AND TOOLS

Let's go to the blacksmith's shop and tell the blacksmith what we have done. You see I've shown you all he taught me about copper, brass, and silver. I promised to take you there when we got through. Come on. Here we are! This is his shop. Mr. Blacksmith, this is my friend. I've shown him how to do work in metal and he can do all that you taught me. We both want to learn how to make things out of steel and iron. Are you ready to take us on?

Yes, boys, you are just in time to help me out. And while you are lending a hand I can show you how to make many things that every boy can learn to do with iron and steel. Come into the shop. First I'll tell you about the blacksmith shop equipment. This is my forge and bellows, with the coal heap at the side; here is the anvil and here are my tools. You see it doesn't take a blacksmith long to name the things he needs to equip his shop. But you must know how each thing is used and what it is used for. Let me draw you a picture of the forge on this board and explain to you how it is built.

_A_ is the chimney. You see it has an opening in the bottom to let the smoke go up. _B_ is a leather bellows. It is placed back of the chimney out of the way of sparks from the forge fire. The nozzle of the bellows goes through a hole ending on the hearth of the forge. _C_ is the hearth where the coal is placed. _D_ is a nest in the centre of the hearth, called a tuyere. Through this opening the blast from the bellows enters the coal heap.

The whole forge is built of brick and mortar. Modern forges are made of iron and steel and have a sheet iron hood in place of a brick chimney. But the principle of the tuyere, where the blast enters the forge, is the same as we blacksmiths have always used. Now I'll build the fire in the forge. Here in this box are some shavings. I save all my shavings and put them here to start my fire with. Place the shavings over the tuyere and light them. Let them burn for a little while, then cover the whole with this soft bituminous coal. This kind of coal is free from sulphur and phosphorus, and it cokes very nicely when the gas and tar are burnt out. Now it's time to use the bellows. You can take hold of this handle and pull down. The weights on the bottom pull the handle up again. Sometimes weights are placed on the top board. This helps to increase the air pressure. Notice that the bellows hang in a frame and the centre axis is fastened to the upright, allowing the upper and lower half to rise and fall. When the lower half falls it sucks the air in through a little trap door on the bottom, and when raised the trap door closes and the air is forced through the nozzle into the tuyere on the forge. This alternates, first taking the air in and then forcing the air out. Pump gently at first, then the coal will not smother the fire. That volume of smoke coming up is mostly from the burning shavings and it goes right up the flue. This blue flame that you see now shows that the gases are burning in the coal. When they are burnt out the coals give a red glow. Now the bright fire is shown through the coal. Put your poker into the coal heap and raise it gently. The opening made on the top is a vent for the heat to escape and prevents the fire blowing into the shop. An opening like this should always be left at the top, on account of the oxygen which is being pumped in constantly. Sprinkle a little water on the coal around the outside of the fire. This helps to pack the coal down tight and keep the fire in a confined space, for it is apt to spread and use up much more coal than is needed.

You see, boys, this is an old-fashioned blacksmith shop. Most of the work done here is horseshoeing, though we have many complex things brought in for us to repair, none of which can be turned away. All these shoes hanging on the rafters are for horses and mules. The mule's shoe, you see, is a different shape from the horse's shoe. I make these in my spare moments and we call them stock shoes. Notice that the stock shoes have no heels or toes on them. These are put on when the shoe is made to fit the horse's foot.

Shoes are now made by machinery and I buy them when I haven't time to make them. But they, too, must be fitted to the foot, for they come only in stock form.

Now I'm going to show you how to make a horseshoe. I'll make it out of this piece of steel tire from a wagon wheel. We use all this kind of scrap to make the stock shoes. That's why our made shoes can be sold cheaper than the manufactured shoes, if we have the time to make them. Steel is being used in place of iron in all branches of industry. A steel shoe weighing half a pound will wear as long as an iron shoe weighing one pound.

This piece of steel tire which I am using is 1 in. wide and 1/2 in. thick. I want to keep the thickness 1/2 in., but reduce the width to 3/4 in. To do this the end of the piece of metal is put into the forge fire. As soon as it is hot enough, I take it out and place it, edge up, on the anvil, and with the hand hammer draw it out any length I wish. You see that driving down on the edge of the hot bar thickens it. Now turn it over and drive on the flat side. You must keep driving first on the edge and then on the side until it is the right size. This is called stretching the metal out. Now the bar is long enough to bend in the shape of a letter U. Heat about 6 ins. of this bar and then place it on the largest part of the anvil horn. Strike on the projecting end with a hand hammer. It bends easily into the shape.

Take the chisel-shaped tool. The edge of this tool makes the groove to fit the nail heads. Every horseshoe has eight rectangular holes for nails, four on each side. These are punched through with this punch, and are made just large enough to fit the horseshoe nail heads. Now you see a stock shoe, and it is just like the dozens I have hanging on the rafters. But before the shoe is placed on the horse's foot it must have the front piece, called the toe calk, welded on and the ends of the shoe turned up for heels. To make the toe calk I take a piece of iron or steel about 2 × 3/4 × 1/2 in. The end of this piece is prepared like this:

The little projection is made very sharp so that it can stick into the hot iron. In this way it is kept in place during the process of welding. When the calk is made I heat the shoe and place the calk in the proper position. The calk is cold and the little projecting point is easily driven into the hot iron. Now that it is held in place it must be welded on. Iron and steel are welded together only by the use of a flux. There are many kinds of fluxes used. For this I shall use _borax_. I buy it by the pound and it comes in boxes like this. Sprinkle a little on the calk, heat it in the fire, watch the fire. When the metal is hot enough to weld you will notice a brown smoke coming from the fire. That tells you the borax is burning. There, see the smoke! Now I must take the shoe out quickly and place it on the anvil. A few quick, light blows upon the calk and the welding is done! The hammering must be done quickly after the shoe has been taken out of the fire, or the cold air will lower the temperature and prevent the metal from uniting. There, it's welded! Now I shape it and fit it to the horse's foot. The heels can't be bent up until I know just how long the horse's foot is. I measure by placing it on the hoof. Then the two ends of the shoe are bent and driven down so that the height of the heels equals the height of the calk. Now, boys, this is a hand made shoe. When you know how to use the fire and the tools it is an easy problem to make a horseshoe.

So it is with all blacksmiths' work. There is not anything about it you can't do. Any boy can build his own blacksmith shop if he has a shed or shelter large enough to keep the rain from a forge, anvil, and some tools. You needn't have the big, old-fashioned brick forge like mine. Here is a picture of a portable forge that I can recommend. It can be bought at almost any store that deals in hardware supplies. It is small and handy and can be easily taken from place to place. You can buy any size anvil you wish. They come in all sizes, weighing from five pounds to five hundred pounds. Here is a list of tools which will do all the work, both ornamental and plain, which you may wish to do. Get this equipment, then build your shop.

BLACKSMITHS' TOOLS

Some of these tools you have used in your copper, brass, and silver work. You will need your vise, files, your various punches, dividers, hand cold chisel, and square. In addition, you should have the following:

_Hand hammer:_ A hand hammer is used more than any other tool in the shop. The flat face is used for shaping material and the round plain for riveting, etc. The top and bottom fullers are used for making depressions in iron and steel. This process is called fullering. The top and bottom swages are used for rounding square iron or steel or reducing large sizes to smaller ones. Hot and cold chisels are both used for cutting iron. As the name shows, one is used for hot iron and one for cold iron. Gouges are for cutting ornamental shapes on sheet iron or steel, hot or cold. Calipers are used for measuring diameters. The broad flat surface of the flatter smoothes rough places. The set hammer is used to make square shoulders. It is a small hammer and does the work in narrow places which larger tools cannot reach. This sledge weighs about eight pounds. It is used where heavy hammering or driving is needed, and in conjunction with such tools as swages, fullers, set hammers, etc. The hardie is a sharp cutting tool used to cut small pieces of iron and soft steel while hot or cold. Tongs are of all sizes. Those most called into use have the following shapes: The shovel for the fire must be small and strong so the clinker formed on the bottom can be shoveled out without carrying too much coal with it. A poker, rake, and dipper also are needed for use about the fire.