In wiring new wooden buildings do not draw wires too tight; the wood may expand and either break wire or cause a weakening of the insulation. In wiring before the plaster is put on, always leave a good length free, so it will not be covered up by the plasterers.
The wire used on the gas fixture is of a special kind, being made for the purpose. It is made in two sizes, No. 22 and No. 24 B. & S. gauge, and with three windings of cotton, three outer layers of cotton and one of silk, or three windings of cotton which is soaked in fireproof preparation, and then wound with silk.
As the piece used is generally short, these small sizes are sufficient in carrying capacity. After wiring up a fixture, this fine wire can be tied on to the pipes, etc., with thread, and a good coating or two of shellac varnish applied. When this is dry, the thread can be removed and the shellac will hold the wires on to the fixture. On no account finally connect up the battery to a circuit when shellacking the wire. Wait until the shellac is thoroughly dry and hard—at least half a day, if possible.
White lead is generally used at the joints where the burner screws into the fixture, but tinfoil wrapped round the joint will give good service. It prevents leaks and ensures a good contact.
The ground connection at the battery must be first-class; do not be content with just wrapping a few turns of wire around the pipe in the cellar (assuming the battery is in the cellar), but clean and scrape the pipe; clean at least two feet of the wire, wind it tightly and evenly on the pipe and solder it. There is a pipe-clamp made which is clamped on the pipe and the wire attached to that, but it must be properly put on a clean surface.
Wiring Finished Houses.
In wiring finished houses, especially wooden ones, the wires can be run along skirting boards, and often pushed out of sight in the space between the floor and the skirting. This is quite permissible, as the wires, unlike electric-light wires, carry no dangerous current; but waterproof wire becomes preferable, as the water used in washing a floor will often creep under and rot the insulation. In going upstairs, wires can often be run in the fluting of a moulding along the stairway, and be quite inconspicuous; but wherever possible, fish the wires up inside the wall. The main thing to be considered in wiring is that the wires are large enough, well insulated, all joints well made and taped and put where there is no danger of injury. Rats have a habit of gnawing paraffin-coated insulation, and it is well to run such in metal tubes. In joining or splicing wires, do it in a thorough manner, and solder if possible. Never use the old bell-hanger joint—the one in which the ends of the wires are merely looped together. Strip insulation and scrape or sand-paper bright about three inches of each wire to be spliced. Then, placing the bare wires across each other about three-quarters of an inch from the insulation, tightly wind the loose bare ends of each around the bare inside portion of the one it is being spliced to. A touch of solder will prevent trouble from oxidation, after the adhesive tape has been wrapped on. Attention to details like these will often ensure the satisfactory working of the job.
A handy tool for gas-lighting wiring is shown in Fig. 25. One end is bored out to fit the small nuts on the ratchet and pendant burners, and the other is filed flat for use as a screw-driver.
Fig. 25.