Tape Applications

That roll of electrical tape on your workbench. Of course it sticks, but does it flag? Will it ooze or flow? How elastic is its memory? What is its elongation?

Tapes have very specific characteristics that make one tape great for high-voltage cables and another the right choice for high-temperature or moisture-prone installations. Do you know how to select the right tape to do your job right the first time? Tapes are grouped by their functions: insulating and splicing tapes, sealing and insulating mastics, and specialty tapes.

Electrical Tape

Premium = Super 33+ (7 mil), Super 88 (8.5 mil),
Scotch 35  (Color Coding 7 mil)

Commercial Grade = 700 (7 mil)

General Purpose = 1700 (7 mil)

Reasons for the Different Tape Thicknesses

Thinner tapes usually apply easier and conform more readily. Thicker tapes offer faster build up , higher dielectric strength, better abrasion and cut through resistance and higher mechanical strength. Be aware that some industry specifications also require different thicknesses.    

General Application Tips

• Apply tape with enough stretch to conform smoothly to the object you are wrapping.  Be sure to let the last inch or so relax before tabbing it down to prevent unwinding (flagging) as the tape recovers.
• Keep fingers close together when tearing tape.  The farther apart they are, the more the tape will stretch before it tears.
• Wrap an irregular mechanical connector, such as a split bolt, with rubber tape to pad sharp edges, before wrapping with vinyl electrical tape.

Choosing a Tape for the Right Application

Vinyl Tape — Jacketing, Low Voltage Splicing, Mechanical Protection

Vinyl tape are commonly used for low voltage electrical insulation (up to 600V). Other uses include strapping, bundling, identifying and holding applications (both temporary and permanent).

Elastic Memory Tape

Elastic memory is one of premium vinyl electrical tapes most desirable properties.  It helps force the tape to conform and the memory action continuously holds the tape in place to provide moisture seal and eliminate voids. 

How to Apply

• Always use a minimum of two half-lapped layers. The last layer wrapped in a more relaxed manner.The last inch to 2 inches should be allowed to relax before thumbing down to avoid “flagging.
• Apply in half lapped layers with enough tension (or stretch) to conform to the object being wrapped.  Apply with no tension on the last wrap to prevent end lift.  Always use a minimum of two half-lapped layers.  More tape layers will provide more insulation, abrasion, as well as cut through resistance.
• When replacing insulation, a good rule of thumb is to build tape thickness to one and a half times the existing wire or cable insulation thickness. When using outdoors consider color coding.  Apply several layers of color coded tape directly over itself for UV protection (unprotected outdoor application) for underlying layers. Remove outer layer as tape fades.

Rubber Tape — Electrical Insulation, Mechanical Padding, Environmental Seal

Rubber tapes provide a fast build of insulating material. These tapes stretch and conform to most irregular surfaces.  On irregular joints and connections, rubber tape generally provides the bulk of insulation build up and water seal.

Rubber tapes create a water seal by forming a gasket around the cable or wire jacket. Most rubber tapes use a liner to prevent the tape layers from bonding or fusing (self-amalgamating characteristic) in place on the roll.  The liner is removed during application. 

Low Voltage Rubber Tapes

Made from ethylene propylene rubber or butyl rubber, this class of tape is  commonly used for insulating, water sealing and padding of connections prior to being over-wrapped with other tapes. They are self-amalgamating, water-resistant, ozone resistant (EPR), weather resistant and UV stable (black).

How to Apply

• Use a half-lapped wrapping technique. Stretch rubber tapes to a minimal ¾ of original width – for ideal results, stretch tape just before breaking point.
• Rubber tapes should be over -wrapped with a vinyl tape for mechanical protection. Be sure that the cable jacket on which rubber tape is being wrapped is clean.

Sealing Insulating Tapes

2200 / 2210 Vinyl Mastic 

2228 Rubber Mastic Tape 

2229 Mastic Tape Compound 

Mastic Tape —  for Low Voltage Insulating, Mechanical Padding & Shaping and Environmental Sealing

Mastic tapes are used for quick and easy insulating, and padding and sealing of wires and connections that need protection from water and adverse environmental conditions.  Mastic tapes are designed to flow and self heal if cut or punctured.

Mastic is a class of aggressively sticky rubber-like compounds.  The compounds make an excellent water seal by adhesion (compared to rubber tapes gasket like seal) to even the slickest wire and cable jacket surfaces. A liner to prevent the tape layers from bonding or fusing (self amalgamating characteristic) in place on the roll. 

How to Apply

• The liner is removed during application.
• Mastic tapes or pads should be over-wrapped with vinyl tape to keep mastic from flowing. or oozing. 

Mastic Tapes for Sealing and Insulating

Vinyl Mastic Tape (2200/2210) (06147/06149)

Combines the abrasion resistance and jacketing of vinyl tape with conformable mastic for sealing.  It can be applied by folding a piece around the connection and sealing the edges.

Rubber Mastic Tape (2228)

Combines the higher voltage insulating capabilities of rubber tapes with the excellent moisture seal and padding of mastic.  This product is excellent for stretching and conforming in tight places.  It has more than 1000% elongation.  This product should be over wrapped with vinyl for mechanical protection.  Since a layer of rubber tape is between thin layers of mastic, this form flows less than the other configurations of mastic. 

Mastic Pads or Rolls (2229)

Are also available.  They can be cut to the appropriate size to minimize waste.  Use mastic for padding, sealing and insulating to smooth out the sharp edges.  After applying mastic, over wrap with vinyl tape to keep the mastic in place and provide mechanical protection.

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