Some 3M Scotch Electrical Tapes Tips & Skills….

Published 06 Sep 2020

3M Scotch Electrical Tapes

3M Scotch Electrical Tapes

  • uploaded by Chris Dodds - Thorne & Derrick Sales Marketing Manager

3M Scotch Electrical Tapes

Once upon a time, 3M introduced a revolutionary electrical tape.

That was in 1946 when the vinyl electrical tape patent was issued and since then 3M Electrical have pioneered the role of electrical tapes for maintenance and repair jobs.

So the humble PVC insulation tape was born and named Scotch 33  – this tape evolved into the mass-market over the proceeding decades to become established as the Number 1 PVC Electrical Tape.

And the rest as they say is history…

  • 1951 Improved aging, higher temperature performance and wet dielectric
  • 1952 Improved cold weather handling characteristics
  • 1953 Improved slitting and telescoping performance
  • 1957 Flame retardant properties developed
  • 1961 Improved adhesive anchorage to cables, joints and splices

Quickly No. 33 Tape manufactured by 3M and branded Scotch became the new standard for insulating electrical connections and cables.

Scotch 33 Tape

In 1966, when England were winning Word Cups, the standard Scotch 33 tape became “Super” – the introduction by 3M of this new and improved electrical tape commonly called “Super 33” had a new operating temperature rating up to 176º F and was coloured black for UV resistance.

All Scotch electrical tapes exhibit smooth unwind and excellent handling characteristics.

Scotch Super 33 TapeEssentially, 3 basic qualities must be carefully evaluated when choosing your tape:

  1. Shear Adhesion or “Holding Power”
  2. Peel Back or “Pull-off Strength
  3. Thumb Appeal or “Quick Stick”

Peel Back measures the adhesive resistance of the electrical tape to be peeled away from the surface to which it is adhered – the thumb appeal measures the quality of the adhesive to actually feel sticky and retain the bond strength without suffering departure from the surface.

This tendency for adhesive “creep” can lead to the need to remove and re-tape the application to maintain the electrical insulation and mechanical protection.

Additionally, consider the following factors when choosing an electrical tape: backing construction, tape thickness, and dielectric strength.

Scotch Electrical Tapes

High tensile strength, excellent elastic memory and stable recovery – specify 3M Scotch

Taping Skills & Tips

Overtime the use of conventional electrical tapes has declined as modern product advances, such as 3M Cold Shrink Tubes, have replaced traditional taped solutions for effecting cable repairs, jointing and termination. Even though electricians are unlikely to consider “old-school” taping skills to be an important element in the engineers skill-set of today the importance of cable splice and termination taping skills for electricians, jointers and linesmen remain a focal element of training courses.

Watch the electrical taping techniques of an experienced cable jointer using 3M Scotch 33 tape to provide electrical insulation layers to the cable  – neutral tails are taped up here with the cable splicer demonstrating the slick pass, stretch and apply method to the Scotch tape.

Cable Replacement at Meritex Caves -- Part 4

Here are several good reasons to master the craft of electrical taping.

When quick “on the spot” electrical and cable repairs are required and other products are simply not available, 3M Scotch Electrical Tapes can be real “day-savers”.

3M Electrical Tapes offer long-term performance, excellent adhesion, chemical resistance and temperature performance – their smooth unwind from the roll can provide “quick-fix” and simple solutions to electrical insulation tasks straight out the engineers pocket.

The primary 3M Scotch tapes used in electrical applications are vinyl, rubber, mastic, varnished cambric and corrosion protection.

3M Scotch Tapes

Thorne & Derrick Stockists & Suppliers | 3M Scotch Tapes

Weatherproof & Watertight Taping 

The function of moisture-sealing tapes such as vinyl, rubber, and mastic products is to exclude moisture from the insulation assembly and provide electrical insulation to cable, splices and terminations. One of these Scotch tapes — or alternatively a 3M mastic pad — generally forms the second layer of the insulation assembly. Rubber, mastic, and filler tapes are also used to pad the underlying surface by covering sharp edges.

LV Tapes

3M rubber tapes are generally non-adhesive and are either equipped with a liner (Scotch 23) or are3M Scotch 23 Tape linerless (Scotch 130C). Stretched and overlapped layers of the tape will fuse or bond together – self amalgamating – to form an effective electrical insulation and moisture barrier. For low-voltage (1000V or less) applications, rubber tapes should be stretched during wrapping so that tape width is reduced to approximately 75%.

Similarly, low voltage inline splices, connectors and joints can be protected using Scotch tape by wrapping the installed connector with four half-lapped layers of rubber mastic tape or rubber splicing tape, and then over-wrapping it with two half lapped layers of premium vinyl electrical tape, such as Scotch 33.

MV & HV Tapes

For high voltage (HV) and medium voltage (MV) applications — where the electrical stresses are high (e.g. connector areas, cable lug areas and cable shield semicon cut-back areas) — electrical tape should be stretched just short of its breaking point.

3M Vinyl Tape forms the final outer layer and serves several important functions in addition to electrical3M Scotch 130C Tape - ex stock insulation, including abrasion protection, corrosion resistance, UV resistance and protection from chemicals including alkalis and acids.

Conformable vinyl tape is tougher than the softer, stickier surfaces of rubber, mastic, and putty tapes it protects. Several grades of vinyl electrical tape are available — all of which differ in conformability, ease of unwinding, resistance of the adhesive to heat and cold, and loosening (flagging).

Brandname Scotch

The Scotch brand is a registered trademark of 3M Electrical and is synonymous with the highest levesl of quality, performance and reliability. So much so, Scotch has became a language term for the entirety of the market niche that the respective brand dominates. But unlike some lapsed and generic trademarks such as Lollipop, Trampoline or Aspirin, the Scotch brand which recognises problem-solving as the ultimate creative act continues to pervade and guide customer choice and preference.

3M Scotch Tape

Insulating Cables

While general-use vinyl tapes are appropriate for bundling, wire pulling and other ancillary tasks, Scotch 35 premium-grade vinyl tape is the best choice for permanent insulation work as it handles the broadest range of environmental factors and functions, such as chemical resistance – available in a rainbow rich choice of colours.

The combination of elastic backing and aggressive adhesive provides moisture-tight electrical and mechanical protection with minimum bulk. For cold weather applications down to – 18°C, Scotch 88 tape is recommended.

3M Scotch 35 and 88 available ex stock

3M Scotch 35 and Scotch Super 88 available ex stock

Electricians should use a minimum of two half-lapped layers of 3M vinyl tape to insulate and jacket low-voltage cables, cable sheaths and electrical components. A half-lap consists of overlaying each turn by one-half the width of the tape. The general rule of thumb calls for a tape thickness of 1.5 times the thickness of existing wire or cable insulation.

Two half-lapped layers of 3M vinyl tape

Two half-lapped layers of 3M vinyl tape

In every case, tension on the electrical tape should be sufficient to conform the 3M Scotch tape evenly to the surface. A slight reduction in tension is encouraged for the final wrap. Trim the Scotch tape end and allow it to return to shape before pressing down with the thumb to avoid lifting or flagging.

  • 3M Scotch Electrical Tapes

Further Reading

How To Repair A Damaged Cable Jacket With 3M Mining Cable Splice Kits 3100 Series

3M Scotch Tapes – PVC Vinyl Electrical Tapes

3M Scotch Tapes

Further details on the complete range of 3M Scotch Electrical Tapes can be found here:

➡ The following tape application table provides an overview of the standard uses of Scotch Electrical tapes:

Scotch Electrical Uses Vinyl Tapes Rubber Tapes Varnished Fabric Tapes Mastic & Filler Putty Tapes
Protective Cable Jacketing X X
Electrical Insulation X X X X
Moisture Sealing X X
ID & Colour Coding X
Cable Harness Bundling X
Mechanical Padding X X X
Shaping X X X
Re-entry X X

➡ Visit 3M Electrical for further information about joints, terminations, tapes and insulation to seal, repair, splice and connect LV MV HV cables.

Cold Shrink

Cold Shrink | Joint | Terminate | Seal | Repair | Splice | LV MV HV Cables | 3M

  • 3M Electrical Products Stocked By Thorne & Derrick International 

Thorne Derrick 35

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