DECORATIVE IRON WORK
Next to the scroll, the twist is perhaps the most characteristic detail of decorative treatment in iron. Twists relieve the plain effect of the straight lines made by the hard edges of the metal, by introducing short curves into the design. The twists are easily made and lend themselves largely for decoration on such things as fire escapes, brackets, grills, gates, fences, and smaller articles, such as umbrella stands, door knockers, fire tools, etc.
The twisting is done best while the iron is cold. If done while the iron is hot great care must be taken to check up when the lines begin to run too close together. Take a bar of square iron, fasten one end in the vise, and with a monkey wrench on the other end give the metal a twist. Only square bars show a change in the shape after twisting. Round stock when placed in the vise and twisted shows no change in shape. However, two pieces of round stock twisted give a very pleasing effect. A braided strand is made (1) by welding the ends of two pieces of round iron together side by side and twisting them, (2) welding ends of two more pieces of the same size and length together and twisting them, (3) by welding these two twisted bars together on both ends and twisting them in the opposite direction. This gives a braided effect which is most decorative. However, the square stock gives the most satisfactory result in all of this twisted work.
Handles can be made by reducing square stock, leaving the centre larger and drawing the ends out to a taper and twisting this tapered part. Begin the twist in the middle and let it rise gradually toward each end. Great care must be taken with this work, as the smallest sizes are also the weakest and naturally bend first. To do this work successfully the metal must be heated and driven a little each time until the whole taper is twisted. Spirals: Spirals are made by drawing a long taper on the end of a round or square bar of small iron. Turn the end of the bar up 1⁄2 in. at right angles. Grasp the turned up end in the vise; coil the end up as you would a coil of rope. Slip one end under the other when they come together. When the first coil reaches the centre of the piece repeat on the other end until the two coils meet in the middle. Heat it all evenly. Grasp both ends in the tongs and pull the spiral out. Stop when the openings equal the size of the iron of which the coil is made.
Ornamental bulbs: Bulbs are used in the same way as spirals and twists, for decorative purposes, on andirons, grills, fences, etc.
The form shown here in the sketch is a very simple one. The principle, however, is the same as that applied to the forging of more complex bulbs. Select a rod of iron for a core. Reduce the thickness to about 1⁄2 in. for about 6 ins. long, leaving the required thickness at the ends; 1⁄2 in. from the shoulder nick the bar around, cutting it almost through. Leave about 1⁄16 in. to hold it to the body of the piece. Cut the core off 1 in. from the 3-in. cut. The picture shows the method of making the core in order to work out the problem. Select a number of pieces of 3⁄16-in. round soft steel the length of the reduced piece and place these around the core, each one fitting close to the next one. If the space is too small or too large when the last piece is put in make the core larger or smaller. These rods should just touch when they lie around the core. Now with a pair of tongs bind all the rods tightly around the core and with the same tongs put one end in the fire and heat red hot. Cover with borax. Take on a welding heat and weld it in a swage, confining the length of the welding to as short a space as possible.
The core prevents the rods from sinking while welding and it also keeps them in place. Reverse the piece. Put the other end in the fire and weld as before. Weld the neck as short as possible. Heat the body of the piece uniformly. Grasp one end of the bar in the vise and with a pair of tongs twist the other end toward the right slowly. While doing so tap lightly on the end with a hammer. This tends to loosen up the rods and help the twisting. Be careful not to twist so much that the rods will break away from the welds. Heat all again. Place it again in the vise and twist in the opposite direction, at the same time driving on the ends. This forces the centre out and gives it a bulb shape. The core should bend up where the cutting is done. Now the core should be driven out. A punch driven in against the core should break it easily where the cut marks are made. These short ends are forced out through the openings between the rods, and any uneven buckles or bends in the rods should be bent or straightened as the case requires. The bulb can be trued up while cold. A punch driven through from the opposite side will help straighten any of the rods bent from the outside in.
