Interlocking Slide Fastener Operation

Ordinary interlocking slide fasteners are designed for flat, smooth operation. Both hands are required for proper functioning. The chains should be stretched taut with one hand and the slider worked (without force) with the other.

When operating an interlocking slide fastener installed in a garment of soft nappy material, or lined with wool or fur, do so with care to prevent the nap or wool from jamming the slider.

Very often grease or oil deposits lodge between the tiny hollow parts of the teeth and accumulate dirt and lint. This causes stiff operation of the slider. A dirty or gummed chain should be cleaned with an old toothbrush or a pipe cleaner saturated with Stoddard solvent or other similarly approved cleaning solvent. After each cleaning, the chain should be lubricated by applying one drop of oil or a small amount of graphite between your thumb and forefinger and running the chain up and down between your fingers several times.

Figure 10-19.-Slide fastener parts.

Figure 10-20.-Slide fastener pull tabs.

A brief inspection will determine whether a slider (or pull tab) is the locking or nonlocking type. Always be certain that the pull tab is lifted at right angles to the slider before attempting to remove the locking type. The relative positions of the pull tabs are shown in figure 10-20.

Interlocking Slide Fastener Tools

In addition to common tools such as screwdrivers, pliers, awls, knives, scissors, and needles, a well-equipped slide fastener kit should be included in the parachute loft equipment.

The interlocking slide fastener kit (zipper repair kit) contains all the parts necessary to repair any size or type of interlocking slide fastener, plus the following special tools: end cutters, or nippers, used for removing stops and teeth; stop-closing pliers, specially designed to span over the slider and clamp the stops in position; and pull-up pliers, designed to close the slider without a pull tab. Another handy tool in slide fastener repair is an awl with a bent tip. This tool maybe used to close the chain by hand.

Interlocking Slide Fastener Repair

A torn or ripped interlocking slide fastener bead cannot be repaired, but should be replaced with a complete new interlocking slide fastener. If the bead is damaged near the top or bottom of the interlocking slide fastener, and the damaged ends can be cut off to shorten the interlocking slide fastener without hampering the usefulness of the garment, an effective repair can be made.

Loose or missing teeth and stops can cause trouble. If teeth or stops are not tightened, they will eventually be lost and tear the bead. In repairing such damage, see that the loose stop is in position (almost touching teeth), and then set tightly with stop-closing pliers. Set any loose teeth parallel with the other teeth in the chain, and then apply pressure with the stop-closing pliers. Set any loose teeth parallel with the other teeth in the chain and apply pressure with the stop-closing pliers. If a replacement stop is not available in the repair kit, a soft wire or heavy thread may be used as a temporary stop.

A missing tooth should be repaired by replacing the entire interlocking slide fastener. However, in the event that there are no spare fasteners available, a missing tooth may be replaced. This is done by carefully removing the stop from the top of the chain, taking off the top tooth, replacing the stop, and setting the tooth in place. (You should be careful not to damage the bead of the chain when resetting the tooth.)

You may run into trouble in moving the slider on the chain. This is caused by the jaws of the slider being too tight, or a dirty chain maybe the trouble. To loosen the slider, insert a screwdriver between the jaws, and very gently pry them apart until they operate freely.

Should the slider become jammed with fur, wool, or other material, carefully remove such matter with a pin or needle while gently pulling the slider until it is released. If it is so badly jammed that it resists all efforts, remove the slider by carefully bending the jaws apart and returning the jaws to their original position. Then replace the slider on the chain (described later).

Most pull tabs have two small projections fitting into slots on each side of the slider. To remove the pull tab, use two pairs of pliers, one on each side, and twist in opposite directions. In

Figure 10-21.-Removing the slider.

replacing pull tabs, this procedure is reversed. Pull tabs furnished as replacements need only to be squeezed onto the slider.

To repair a damaged slider, you must first remove it. The proper procedure for removing and replacing a slider on the chain following repairs is explained in the following paragraphs.

To remove the slider from the regular type interlocking slide fastener (nonseparating), carefully rip the stitches from the BOTTOM of the interlocking slide fastener to expose the ends of the tape. Then remove the bottom stop, and slip the slider off the bottom of the chain and entirely off the beads and tape, as shown in figure 10-21.

To replace the slider on a regular type interlocking slide fastener, thread the two bottom beads into the wide end of the slider. Hold the tape so that the bottom teeth are correctly matched; then draw the slider upward until the teeth mesh for several inches. Without allowing the teeth to separate, clamp the bottom stop close to the teeth and over both beads. Replace the tape ends and ripped stitches by hand or by machine.

To remove a damaged slider on a separating type slide fastener, carefully rip the stitches at the TOP of the slide fastener, on the retainer side only, thus exposing the end of the tape. Remove the top stop, slip the slider off the top of the chain, and completely remove it from the bead and tape. Repair or replace the slider.

To replace the slider on a separating type interlocking slide fastener, thread the bead on the retainer side into the narrow end of the slider, and allow the slider to slip down the chain. Replace the tape end and ripped stitches by hand or machine.

To replace the slider on the top of a regular, nonseparating type interlocking slide fastener with the aid of pull-up pliers, slip the tool over the bottom stop, clamp together, and pull upward. Close the entire chain in this manner. Thread the two top beads into the narrow end of the slider, holding the teeth meshed until they enter the slider. Replace the top stops, tape ends, and ripped stitches.