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the glassy appearance starts to show, take the steel from the fire and forge it as desired.

Charcoal or coke makes the best fire in an ordinary forge, as these fuels are sulphur-free and lack most of the gases common to bituminous coal. Bituminous coal, ground fine, is the next best fuel in the forge. It should be piled two or more inches deep around the fire and well wet-down with water, which causes it to coke, making a better fuel of it.

Either the gas or the electric furnace may be used in forging instead of the open forge. Their positive temperature control makes them ideal for the purpose.

Lighter hammer blows should be used in forging thin sections of high-carbon steel, such as gun springs, than in forging the low-carbon steels, for this carbon-steel spring-stock is forged at the lower temperature, as mentioned above, is a more brittle steel and will develop surface checks or cracks more easily than the low-carbon steels. In fact, this brings out another point in forging, that of surface hardening by the hammer method. Hammering a piece of steel, either hot or cold, changes the surface structure of it, making the grain finer and more dense, which in turn makes the surface harder, which is the cause of the surface checks or cracks. This is quite pronounced in forging steel cold and quickly develops. Before the introduction of case-hardening, this method was used by the smiths to give surface hardness to steels to cut down wear. The low-carbon steel is heated almost to welding temperature and, while kept as close to this temperature as possible, it is hammered with fairly heavy blows with a heavy, flat-faced hammer, which treatment gives the steel the dense surface mentioned.

Forge or hammer welding is done at the higher temperatures just below the burning heat for the steel. The pieces to be welded are scarfed (cut off or heated and pounded-out on a taper) then heated in the forge

Kinds Guns Firearms

Various types of welding, made at the forge. A is lap weld, B is forked weld of round stock. C is jump weld. D is forked weld. E is a Tee weld and F is a double lap weld of thin stock.

until the surface is quite glassy-looking and almost at white-heat. Just as the steel reaches this heat the flux, of powdered borax, or ground-glass and powdered clay, is sprinkled on the heated surfaces and allowed to melt, as the heating is continued for a minute longer. The pieces are then taken from the forge to the anvil and laid upon each other at the point the weld is to be made and, while holding the upper one in a pair of tongs, it is hammered into the lower piece with heavy, rapid, hammer blows. The pieces, if properly prepared and heated, stick to each other at once and as the steel cools to cherry-red they are returned to the fire, more flux added and reheated to the white welding-heat, again withdrawn and hammered together again, with the performance repeated until the weld is perfect and no dividing line shows between the pieces.

The above weld is what is called a lap-weld, from the fact that one piece is lapped upon the other in making the weld. A second type of weld is the fork-weld, in which one piece is split for a short distance and the two sides opened up in a vee-shape. The piece to be welded to this is then scarfed or cut off on both sides to a chisel edge at the end and is placed inside the vee or fork, when both are heated to welding temperature and the sides of the vee are then hammered down upon the inserted, chisel-shaped end of the second piece. Thin pieces, to be welded together end to end, are often split for a short distance and the split ends of each piece are then bent in opposite directions, just as you take a sheet of paper in your hands and pull one hand toward you and push the other hand awa}' from you to tear the paper. This is done with each piece at one end, then in making the weld the two pieces are placed together so that the bent split-ends lap upon each other and are then hammered down, one into the other. In making a tee-weld, a spot on one side of the top or bar of the tee is scarfed-off and the end of the other piece, which is to be laid in at this point, is also scarfed-off and when being welded is laid into place and hammered down. This is the tee-weld used in welding flat stock. The tee-weld made in round stock is called a jump-weld, the top or bar is notched in a vee-shape at the point of the weld and the second piece is ground or cut off in a very blunt chiscl shape, then set into the vee-notch.

A successful weld depends, just as in brazing and soldering, upon clean, properly fluxed surfaces and plenty of heat. Hammering a weld after it has cooled too much is very liable to open it right up, if done on the first heat before the weld is completed.

Welding with the oxy-acetylene torch is much faster and more satisfactory than the forge and hammer weld. It is also applicable to much larger pieces. Its drawback for the gunshop is the cost of the equipment, which may run anywhere from $50.00 to $200.00. If only a small amount of welding is done the oxygen may be bought in the small tanks, under the name of medical oxygen, from a physicians and surgeons supply house, and the acetylene bought in Prest-O-Lite tanks. This will make both the oxygen and acetylene a little more expensive, but the investment is less than the large tanks and you get away from the monthly rental charge they assess you on the large tanks.

A large torch does not work well on small parts, so two torches are necessary, one large one for heavy work and quick heating for bolt-bending jobs, with a small torch of the airplane type for small work such as on extractors, front sights and barrel band work.

Parts to be welded are scarfed or cut off at the ends on a much shorter and steeper taper than for forge welding and the ends are butted together, the scarfed portions thus forming a vee. The ends are heated to the melting point and the welding rod is brought to the point of the weld and melted into the vee, building

Large Welded Front Sights

The acetylene welding torch, with tanks and gauges.

it up above the surface of the surrounding metal. In welding steel, and usually in welding cast-iron, no flux is required but in welding aluminum or in brazing or welding brass a flux is required. The prepared flux for each of these metals is the one that should be used, although borax does a very good job on the brass.

Thin or medium-thick parts to be welded need only be scarfed on one side and the weld made completely from this side. Thick, heavy pieces should be scarfed on each side, or in the case of round stock, all around, leaving the two ends to be welded in a point, and the weld made from both sides or all around.

Very large pieces should be preheated before being welded. If the pieces are very thick, this is best done in a furnace or large forge, but if not too thick it may

Acetylene Oxygen Neutral Flame

Various methods of arc welding. A shows the scarfing of thick stock in preparation for acetylcne or electric arc welding. B and C arc methods of scarfing medium and thin stock. D and E are methods for scarfing round stock.

be done with a large heating torch, such as the large kerosene-burning torches. This preheating assures a good weld by even expansion and contraction of the work and avoids expense by saving on oxygen and acetylene gas.

A neutral flame is used in welding, as too much oxygen oxidizes the weld and too much acetylene carbonizes it. Oxidation causes the metal to scale on the surface while carbonizing it makes it very hard, so that it may be too brittle and cannot be machined without annealing. A manual and full instructions accompanies a welding outfit, which covers all the necessary points of torch adjustment and many others.

The electric welding outfits have some advantages over the gas welding outfits for gun work, for one of the big drawbacks of the gas welding torch is the large amount of metal surrounding the weld which is also heated. While this may be an advantage in assuring a perfect union of the two pieces, it has its disadvan tages by often annealing a hard part close to the weld, which must then be rehardened. The gas torch is more to be desired in heating work to be bent, as while the electric arc-welder is supplied with a carbon point for heating, it is more difficult for instance to heat a bolt-handle for bending with the arc-welder than with the gas torch. On the other hand for a build-up job, such as lengthening an extractor or a

Acetylene Welding Bolt Handles

Kerosene preheating torch for preheating heavy work before it is welded with the acetylene torch.

job of welding a bolt-handle back onto a bolt at a different angle, the electric arc-weldcr spreads its heat so little beyond the weld that it is to be preferred to the gas torch. Electric welding is much faster than gas welding, for it takes quite a little while to heat up the parts to welding temperature with the gas torch but with the arc-welder as soon as the arc is struck the metal is at welding heat. The arc-welder, A.C., will cost practically the same as the gas welder of the same capacity, but the cost of operation is less for the arc-welder tlian for the gas welder. In using the gas welding torch, dark-glass goggles are used to protect the eyes from the glare but in using the arc-welder gloves and a face mask are used to protect the skin from the rays of the arc. This mask has dark glass set in it to protect the eyes from the glare as well as from the rays of the arc.

The weld itself is prepared by scarfing in the same way for the electric arc-weld as for the gas torch weld. One terminal wire of the arc-welder is fastened to the work or to a steel plate upon which the work is placed and the other terminal wire goes to the torch or hand

clamp in which the welding rod is held. This rod is different from the welding rod used for gas welding and is usually coated or shielded.

In making the weld the welding rod, held in the electrode clamp, is touched to the weld and withdrawn slightly, which strikes an arc of very high temperature. The welding rod is held steadily at about this same distance from the work to maintain the arc while the rod melts and runs into the weld, where it is built up above the surrounding metal just as was done in making a weld with the gas torch. The proper welding heat for different thicknesses of work is controlled by different current taps on the welding machine.

In brazing or in heating or cutting with the electric arc-welder, a carbon rod is used in the electrode clamp in place of welding rod. The regular brass rod for brazing, such as is used with the gas torch, is used in brazing. With this carbon tip, soldering and spot-annealing, such as softening receivers at points where holes are to be drilled and tapped, is easily and quickly done. In spot-annealing, the heat is so high and so instantaneous that the desired spot is annealed and the heating carbon removed from the surface before the heat has time to spread any distance from the spot

The A. C. type of electric arc welder. The mask shown is used with both types of electric arc welders.

annealed. Electric arc-welding is somewhat simpler and easier to learn than gas welding, due to the much wider range or torch control on the gas torch to regulate heat, along with the several different size tips for the gas torch.

The D.C. type electric arc-welder of the motor-generator type is much more expensive than the A.C. type. These D.C. types have been in the field for many years and have proven satisfactory, although they are so expensive that unless a shop has enough work

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Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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