procedure for tying a wire group or bundle. The tie is started  by wrapping the cord around the wire group to tie a clove- hitch knot. Then, a square knot with an extra loop is tied and  the free ends of the cord trimmed. Temporary ties are sometimes used in making up and  installing wire groups and bundles. Colored cord is normally  used to make temporary ties, since they are removed when  the installation is complete. Whether lacing or tying, bundles should be secured tightly  enough to prevent slipping, but not so tightly that the cord  cuts into or deforms the insulation. This applies especially  to coaxial cable, which has a soft dielectric insulation  between the inner and outer conductor. Coxial cables have  been damaged by the use of lacing materials or by methods  of lacing or tying wire bundles that cause a concentrated  force on the cable insulation. Elastic lacing materials,  small-diameter lacing cord, and excessive tightening deform  the interconductor insulation and result in short circuits or  impedance changes. Flat nylon braided waxed lacing tape  should be used for lacing or tying any wire bundles containing  coaxial cables. Aluminum wire must be stripped using extreme care, since  individual strands break very easily after being nicked. The following general precautions are recommended when  stripping any type of wire: The part of a wire group or bundle located inside a conduit  is not tied or laced; however, wire groups or bundles inside  enclosures, such as junction boxes, should be laced only. To make installation, maintenance, and repair easier, runs of  wire and cable in aircraft are broken at specified locations  by junctions, such as connectors, terminal blocks, or buses.  Before assembly to these junctions, wires and cables must  be cut to length. All wires and cables should be cut to the lengths specified on  drawings and wiring diagrams. The cut should be made clean  and square, and the wire or cable should not be deformed.  If necessary, large diameter wire should be reshaped after  cutting. Good cuts can be made only if the blades of cutting  tools are sharp and free from nicks. A dull blade deforms  and extrudes wire ends. Nearly all wire and cable used as electrical conductors are  covered with some type of insulation. In order to make  electrical connections with the wire, a part of this insulation  must be removed to expose the bare conductor. Copper wire  can be stripped in a number of ways depending on the size and  insulation.  Figure 4-100  lists some types of stripping tools  recommended for various wire sizes and types of insulation. A pair of hand wire strippers is shown in  Figure 4-101 . This tool is commonly used to strip most types of wire. The  following general procedures describe the steps for stripping  wire with a hand stripper.  [Figure 4-102] 4-58 Stripping Wire and Cable Cutting Wire and Cable Figure 4-100.  Wire strippers for copper wire. Stripper  Wire Size  Insulations #26–#4  All except asbestos #26–#4 All #20–#6 All #26–#8 All #2–#0000 All Hot blade Rotary, electric Bench Hand pliers Knife 1.  When using any type of wire stripper, hold the wire  so that it is perpendicular to the cutting blades. 2.  Adjust automatic stripping tools carefully; follow the  manufacturer’s instructions to avoid nicking, cutting,  or otherwise damaging strands. This is especially  important for aluminum wires and for copper wires  smaller than No. 10. Examine stripped wires for  damage. Cut off and restrip, if length is sufficient,  or reject and replace any wires with more than the  allowable number of nicked or broken strands listed  in the manufacturer’s instructions. 3.  Make sure insulation is clean cut with no frayed or  ragged edges. Trim, if necessary. 4.  Make sure all insulation is removed from stripped area.  Some types of wires are supplied with a transparent  layer of insulation between the conductor and the  primary insulation. If this is present, remove it. 5.  When using hand wire strippers to remove lengths of  insulation longer than  3 ⁄ 4  inch, it is easier to accomplish  in two or more operations. 6.  Retwist copper strands by hand or with pliers, if  necessary, to restore natural lay and tightness of strands. 1.  Insert wire into exact center of correct cutting slot  for wire size to be stripped. Each slot is marked with  wire size. 2.  Close handles together as far as they will go. 3.  Release handles allowing wire holder to return to the  open position.