Fig. 63.—This Illustration Shows how the Open Ends of Thin Cast-iron Pieces Spread apart as the Weld Progresses. To Close the Edges together, Jump the Torch Flame from B to A; as A heats up, B Cools and the Lever-like Action Closes the Opening.
(96) To weld a broken automobile frame successfully the body of the car should be raised if necessary, to keep it from burning and all pipes, wires and gasoline leads protected with a covering of asbestos paper. Plenty of room should be allowed, so that the welder may have easy access to the break, and the frame should be jacked up on both sides of the break until the frame is in proper alignment. Then weld the crack from the outside, working across the top, then down the side and across the bottom, reinforcing a little if necessary on all sides but the bottom. Then repeat this operation on the inside, reinforcing at all points. Then take a strip of steel about one-eighth or one-quarter inch thick and six or eight inches long and as wide as the bottom of the frame. This piece should be welded securely to the bottom of the frame with the former break in the middle of the strip. A cut representing this job is shown in [Fig. 64]. By this method the frame can be made stronger than originally.
Fig. 64.—A Good Method of Reinforcing a Weld on an Automobile Frame is Here Shown. The Patch as Pictured Here is only “Tacked On.” It Should be Welded Securely to the Bottom of the Frame on all Four of its Edges.
Part Three.—STEEL WELDING
(97) Aside from the difficulties already mentioned in steel welding, there are many others. A few of these will be taken up in order to let the beginner know how to approach the various problems which may confront him. But in no wise is this to be considered to be a treatise on advanced work. Ofttimes the question arises, Can springs be successfully welded? Now, while springs have been welded, and they have been tested out thoroughly, yet the practice of spring welding with the oxy-acetylene flame is not to be recommended. 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. Now, if there is a fracture and a foreign metal, which under no circumstances can be expected to take the same hardening as the rest of the spring, is introduced into the weld, it can easily be seen why a fusion of this kind is not to be relied upon. If it were possible to diagnose or take an analysis of the metal in the spring and use a filler-rod which, after being acted upon by the flame, would come out the same as the metal in the spring, then some success might be expected, but until that time, welding of springs will not be encouraged. Unless perchance the break is of such a nature that it can be reinforced readily and is in such a position that a resilient quality is not necessary.
Fig. 65.—Building Up Worn Shafts.
(98) Work on crank-shafts often causes perplexity on the part of the beginner, for he usually hears this matter discussed pro and con. Crank-shafts of four inches in diameter can be successfully welded with the oxy-acetylene flame, and even larger, if correct methods are employed. There are many points which the welder considers before deciding whether a weld of this nature is advisable. Of course the usability of the piece after it has been welded is the main issue when executing any kind of a repair job. Now, a crank-shaft will generally break in either of two ways; by some external force, such as a connecting rod breaking loose, or by crystallization, which is usually due to fatigue. Now, in the latter case, ofttimes the shaft will break in the cheek of the “offset,” and possibly no part of the shaft is thrown out of alignment. When such is the case, welding is usually recommended and the shaft may be brought back to a useful state in very quick order. However, in the former case, the shaft is apt to be sprung, and while it could be welded, the machine work necessary to restore it to normal requires much time, and it has been known, where after spending a matter of days in trying to get proper alignments, work was scrapped as useless. So it is entirely up to the welder in work of this kind to determine whether the job is worth while or not. There are certain parts of a crank-shaft upon which welding work can be done with a marked degree of success, such as building up worn bearings and the like. In doing work of this kind it is recommended that the welder fuse his metal in a line parallel to the center line of the bearing, seeing to it that he has a perfect fusion between the surface of the bearing and the metal he is fusing and adding plenty of metal, to insure enough being used, so that no low spots will show up when it is machined. It is considered that by adding the metal as suggested the welder will hold his heat much better than if he attempted revolving the shaft continually. [Fig. 65] will show the method here outlined in a very clear way.
