Material. Flat vehicle-spring steel 10 to 12 mm thick, 35 mm wide and 70 mm long, or as available; scrap railway-line metal.
Additional tools. Top and bottom fullers, about 25 mm; sharp hot set; file; flatter; vice.
Fullers are tools important to the smith and particularly so when a helper is available. They are used for rapid, rough drawing-down of heavy sections, for spreading metal in the direction required for making radiused grooves and recesses and, in some cases, for bending material. Ideally they should be made from steel with a carbon content of 0.7 to 0.75 percent. However, in practice it has been found that spring steel, railway-line steel and even some axle shafts provide materials that will make functional tools with a reasonably useable life.
For smaller fullers, the steps shown in Fig. 122 can be followed. The sizes given are for guidance only and depend on the material available and the size of tool required. The head end is formed as for the sets in Job 11 and a rod handle is fitted as in Job 11 after completion. The radiused end is shaped by grinding, filing or rasping while hot. After forging, the tool is normalized and left in this condition. The natural hardness of the metal is sufficient for the working of hot metal. For larger fullers the procedure illustrated in Fig. 123 can be adopted.
The metal is first upset to a little more than the finished thickness of the tool (Fig .123B). The heat is restricted to the end by cooling with water. Take care not to quench completely any part of the workpiece from red heat. Merely reduce the temperature, leaving the hottest part where the upsetting is to take place. If the steel is completely quenched from high temperatures, excessive hardness will result. The metal will then shatter if struck with hammer blows, creating dangerous flying particles that may damage tools and possibly the anvil face. After upsetting, the head of the tool is formed with fullered recesses as in Job 11. Next, the tool is drawn-down to the finished thickness, radiused as before, normalized and fitted with a rod handle.
Larger fullers can be made from scrap railway-line metal but much more work is involved. If oxyacetylene cutting equipment is available, it is simple to remove the top section of the rail from the web and foot and to cut it into suitable lengths. If the rail is heated to a good red heat and then cooled slowly in lime, sand or ashes, it can be cut with a hacksaw, but this is a laborious process.
Failing other means, heating and cutting with a hot set is the method to use. Slow heating in a large fire with adequate air blast is advised, but make sure that the heat penetrates right through the metal.
Cut off the web and foot of the rail as close as possible to the top section, cutting from both sides. Then cut off a suitable length (Figs 124A and B). Reheat to a good yellow heat and forge the piece to the largest rectangular section possible with neat, straight sides (Fig. 124C). Mark off (Fig. 124C) and cut off the corners, again working from both sides, leaving the piece as in Fig. 124D. Next, fuller and draw-down the head end (Fig. 125A).
The working end is next forged to the finished thickness of the tool and the corners trimmed off the working end with a hot set (Fig. 125B). This end is then finished off by grinding, filing or hot rasping to the correct radius. Normalize the tool and fit a rod handle. Again, for hot metalworking, hardening and tempering are not necessary.
Bottom fullers are the counterparts of the top tools and fit into the tool hole of the anvil. Tool holes vary in size as do anvils. In general, tool holes are from about 20 to 40 mm square. Small bottom fullers can be made to fit into the pritchel or punching hole, which may be from about 15 to 20 mm in diameter. For the smaller bottom fullers, flat spring steel can again be used. Production steps are shown in Fig. 126. Sizes are not indicated but can easily be estimated according to tool and anvil size. The height of the tool top above the anvil face should be kept down to 40 or 50 mm.
Straighten a length of spring leaf, mark out the tenon and cut out with a hot set (Fig. 126B). Forge off the corners and round down to a neat fit into the pritchel or punching hole of the anvil. Reheat and cut off about 40 mm from this shoulder, cutting from both sides. Heat the whole to a bright red heat, partially cool to the top of the tool, place into the anvil hole and hammer it down into the hole to square the shoulders and provide a neat seating on to the anvil face. Remove it from the hole and straighten it as needed. Heat and trim off the edges of the top of the tool (Fig. 126C). Round up this end to the correct radius by grinding, filing or hot rasping. Normalize and leave in that condition.
Swages of both smaller and larger sizes can be made from scrap railway-line metal, using part of the web (the middle of the rail) to fit in to the tool hole. The web can be made to fit the hole in only one direction but will work well in practice. The procedure from start to finish is shown in Fig. 127.
By oxyacetylene cutting or by using a hot set, a piece of rail is cut off slightly longer than the size of the tool hole. Cut off part of the web, leaving 25 mm or so of the web attached to the rail (Fig. 127A). The X dimension is the tool-hole size. Using tongs to hold the web, reheat and flatten the piece to get rid of ragged edges from cutting and to make the portion of web a neat fit in to the tool hole. Reheat, place into the tool hole and flatten (Fig. 128) to seat the tool into position and to give a neat flat top surface.
The job is reheated to a good yellow heat, held in tongs and drawn-down (Fig. 129). Using a fuller speeds up this operation and finishing is carried out with hammer, set hammer or flatter. Heat again and trim off edges with a hot set (Fig. 130) from both sides. By hot rasping, filing or grinding, form the correct radius. Now normalize and the tool is ready for use (Fig. 127C).
For occasional use or in an emergency, shallow fullering can be carried out (Fig. 131). Bend a suitable piece of rod and place it on the anvil face as shown. (The bent ends prevent it from rolling about on the anvil.) A second piece of bar can be used as a top fuller as indicated. This method can be used when making sets and fullers for the first time. It is important to take great care to ensure that hammer blows fall squarely (H in Fig. 131) and exactly opposite the hot metal. If hammer blows are off centre, the top bar may kick up or down violently and injure the smith's hand or wrist.