Weld

“ An experienced welder will always know just what kind of a flame action he is obtaining on his weld, not because he takes the flame away every time he wishes to look at it, but he can tell by the action of his metal exactly the nature of his flame. ”

“ While it is possible to weld cast iron on the vertical, by the use of carbon blocks and so forth, the same kind of work can be accomplished on steel with much ease, without the use of any blocks, or materials other than the filler-rod and the welding torch. ”

“ There are those who will weld leaf springs, such as are found on automobiles, and will apply rapid blows with the hammer, while their weld is still in a heated condition and then plunge the spring in water or oil to harden it and the weld. A close observer will readily see why this procedure is not correct. Springs of this nature are made up of metal which takes a uniform hardening, and were it not so they could not be considered springs. ”

“ The unhammered weld, as ordinarily made by the electric process, has substantially the same strength as the annealed metal of the bar, the break under tensile strain, when the burr at the weld is left on, usually occurring a little to one side of the joint proper, where the metal has been annealed by heating. Hammering or forging the joint while the metal cools, in the case of malleable metals such as iron or copper, will usually greatly toughen the metal, and it should be resorted to where a maximum of strength is desired. ”

“ These welding rods should always be used to fill the weld when the thickness of material makes their employment necessary, and additional metal should always be added at the weld when possible as the joint cannot have the same strength as the original piece if made or dressed off flush with the surfaces around the weld. ”

“ It is recommended, if possible, to use the drawn rods whenever available; for a weld at best is only a casting, and if this casting can be made from virgin metal, rather than recast from metal which has been cast many times and the contents not known, it is thought that the results will be far more satisfactory. ”

“ The judgment of the operator will be called upon to decide just where a piece of metal should be heated to open the weld properly. It is often possible to apply the preheating flame to a point some distance from the point of work if the parts are so connected that the expansion of the heated part will serve to draw the edges of the weld apart. Whatever part of the work is heated to cause expansion and separation, this part must remain hot during the entire time of welding and must then cool slowly at the same time as the metal in the weld cools. ”

“ A weld joint must as a rule be fluxed, or metal will not adhere to metal. There is not, however, the absolute need for fluxing that there is in soldered joints, and many welds in good fibrous iron are made without a flux. But the explanation here is that the metal is brought to a temperature of semifusion, and the shapes of joints are generally such that particles of scale are squeezed out from between the joint in the act of closing the weld. ”

“ The welding of two pieces of stock by scarfing and lapping is known as a separate-heat-weld, so called because the pieces are detached while the heat is taken. In making any kind of a weld there is more or less stock wasted in the raising of the welding heat, therefore the parts to be lapped and welded are always upset or thickened and then scarfed. ”

“ More practice is required to successfully weld steel than most other metals and the beginner should not be discouraged if it takes him some time to conquer this metal. It should be forcibly impressed on the student that the metal must be in a molten condition before the filler-rod is added, or else it will stick and prevent his working readily and in addition will produce a very faulty weld. [87] Fusion is the thing to bear in mind for without it success cannot be expected.
Fig. 60.—This Method of Adding the “Filler-rod” when Welding is not Recommended for the Beginner. ”

“ Some welders find that hard spots develop in their welds which they have difficulty in overcoming, and it is a very serious handicap when the weld is to be machined, for ofttimes it will break very expensive tools and leave a portion of a drill or die broken off in the metal. ”

“ It may be too small now; there is not enough metal to clean up under the tools of the slotting- or shaping-machine.
Then there is the smith’s weld or bend to be considered. In the first place, the smith is liable to mistake the heat of his parts by gaslight, for then they appear brighter and hotter than they really are, and when he brings them out to the anvil, the metal, instead of shutting up well, will be hard and glassy under the tools. It will, consequently, go together badly and leave a mark or “scarf,” which is not at all desirable, though the weld may be strong enough inside. ”

“ The preface says further, “The workman who can successfully weld all automobile parts is capable of welding anything, since in the construction of the automobile practically every commercial metal is used. The principles of automobile welding are applicable to all kinds of welding.” Contents: Apparatus knowledge; Shop equipment and initial procedure; Cast iron; Aluminum; Steel; Malleable iron, copper, brass, bronze; Carbon burning and other uses of oxygen and acetylene; How to figure cost of welding. ”

“ It took both time and patience to weld every one of those links together.”
“I don’t think I understand what weld means,” said Billy.
“When iron is heated to a white heat,” said Mr. Prescott, “it can be hammered together into one piece. Most metals have to be soldered, you know. The blacksmiths generally use a powder that will make the iron weld more easily, because it makes the iron soften more quickly, but iron is its own solder. ”

“ All precautions should be taken to see that no sudden jarring is given the piece until the weld has completely set. When this work is done many welders plunge their work in water, in an effort to make it more ductile and easier to machine. ”

“ It requires some practice to be able to take two pieces from the fire and place them in position on the anvil to be welded. This should be practiced by the pupil under the eye of the teacher, perhaps a dozen or more times, with the cold pieces before he undertakes to get the welding heat. If one cannot take the pieces out and place them in position, he cannot make a weld of this kind. ”

“ The metal can be added faster and more easily controlled.
Rods or wires of Norway iron are used for steel welding in almost all cases. The purity of this grade of iron gives a homogeneous, soft weld of even texture, great ductility and exceptionally good machining qualities. For welding heavy steel castings, a rod of rolled carbon steel is employed. For working on high carbon steel, a rod of the steel being welded must be employed and for alloy steels, such as nickel, manganese, vanadium, etc., special rods of suitable alloy composition are preferable. ”

“ The welding flame should be played on the work around the crack and gradually brought to bear on the work. The bottom of the bevel should be joined first and it will be noted that the cast iron tends to run toward the flame, but does not stick together easily. A hard and porous weld should be carefully guarded against, as described above, and upon completion of the work the welded surface should be scraped with a file, while still red hot, in order to remove the surface scale. ”

“ The flux produces with the oxide a fluid slag which is squeezed out at the instant of making the weld. The commonest fluxes are sand, used chiefly with wrought iron, and borax, used with steel; they are dusted over the joint faces both while in the fire and on the anvil. Mechanical cleanliness is ensured by healing the ends in a clean hollow fire previously prepared, and in brushing off any adherent particles of fuel before closing the weld. ”

“ When working on shafts the welder will encounter such articles as automobile propeller shafts and rear axles, which generally break adjoining the square ends. He will no doubt wonder whether it is advisable to weld this square end back on, or whether to try and build up the shaft the desired length. Undoubtedly the point of fracture is the weakest portion of the entire shaft, else it would not break there. The execution of a weld at this point where no additional metal can be added or any means of reinforcing used is not to be recommended. Fig. ”

“ It sometimes becomes necessary to weld steel and iron together; this may be effected by the same process as that employed in welding steel to steel. None but workmen of thorough experience would be apt to succeed in either case, on the old plan of proceeding the same as in welding iron to iron. ”

“ The ease with which aluminum is puddled together, which many welders have likened to the children’s method of making mud pies, seems so simple to the beginner that he cannot see where the strength comes from when cooled. On account of this, he invariably works his aluminum too long. After welding a few test bars of this metal and breaking them in the line of weld, many old welders will gain confidence upon seeing the results of their own efforts. ”

“ None of the melted metal is allowed to precede the flame, and at all times the operator can see whether the edges to be fused are at the right heat. As soon as the bottom is reached, the weld can again be gone over if it is not thought strong enough, and reinforced as much as desired. As soon as the operator is familiar with this method, he will find that much more speed can be developed, less filler-rod lost and less lapping done than by building up from the bottom. ”

“ Enough flux is blown off the rod into the weld to clean up the surface and permit the metal flowing together. The crack should be melted together all along before any additional metal is added, for the elimination of the crack is extremely important. ”

“ If additional metal is run between two adjoining surfaces which are parts of a surrounding body of cool metal, this added metal will cool while the surfaces themselves are held stationary in the position they originally occupied. The inevitable result is that the metal added will crack under the strain, or, if the weld is exceptionally strong, the main body of the work will be broken by the force of contraction. To overcome these difficulties is the second and most important reason for preheating and also for slow cooling following the completion of the weld. ”

“ To insure a perfect weld, a good quality of material should be selected for the wedges. It should be thoroughly hammered to produce good texture, and if iron is operated upon, the fiber of the wedges should run parallel to the fiber of the piece to be welded. ”

“ The theory of having a planed metal top for lining up work does not prove as satisfactory in actual practice as might be expected, for the simple reason that the average welder generally places his metal in direct contact with this cold top, and much of the heat which is supposed to go into the weld is conducted away by the table top, producing a hard, brittle weld. ”

“ When the hammer beats the heated metals an additional increment of heat is imparted to the weld, due to the forcing together of the molecules of the iron, so that these two agencies, namely, the compound and the mechanical friction, act together to unite the particles of the metal. ”

“ The process is also largely applied to the welding of iron and copper wires used for electric lines and conductors, of steel axles, tyres and metal frames used in carriage work, and of such parts of bicycles as pedals, crank hangers, seat posts, forks, and steel tubing for the frames. The heat, whether it be utilized in welding or brazing, is so sharply localized that no damage is done to the finish of surfaces a short distance from the weld or joint. ”

“ Place the axles on the anvil, securing them to prevent their slipping, and while one man places his hammer full on the weld, give the extremity of the lap or weld a smart blow or two, and if it adheres then both sledges can be applied until a true and workmanlike weld is formed. ”

“ Generally there are some strains left in every cylinder block of this nature. If the water in the water-jacket freezes or some other force comes in contact with the thin castings which constitute a block, the metal will give way at its weakest point, and the welder is usually called upon to repair it. At times these cracks are exceedingly small and the temptation is to braze or attempt to weld the small portions. ”

“ All spoiled, burned, corroded and rough particles must positively be removed with chisel and hammer and with a free application of emery cloth and wire brush. The metal exposed to the welding flame should be perfectly clean and bright all over, or else the additional material will not unite, but will only stick at best.
Following the cleaning it is always necessary to bevel, or champfer, the edges except in the thinnest sheet metal. To make a weld that will hold, the metal must be made into one piece, without holes or unfilled portions at any point, and must be solid from inside to outside. ”

“ In welding cast steel the same procedure takes place as previously described for steel, and it should present no real difficulties after that process is understood. There may be more sand, oxide and other impurities present on account of the nature of the metal, but these can all be worked out if plenty of heat is applied. At times, when working in steel, it will be found that there may be a small hole develop in the center of the weld and as the torch is worked into this hole it is found that it goes down a short distance and seemingly refuses to be worked out. ”