I found some electrical tape in my stash of parts I think got a bunch in a box from a yard sale. The one roll is odd looks nearly identical to standard tape, but a bit wider and no adhesive. I've never seen this before I have seen older stuff become not very sticky, but usually something left. This is wired. I looked online some only thing I see is called self vulcanizing tape, but I can't find out anything about it. to me sounds like either activate by heating it, or just stretching and friction holds.
also found a few other odd rolls that are like black cloth with adhesive. they say electrical tape, but all tape I've ever seen is plastic/ rubber. Not sure if like asbestos and I should pitch or just something special, or old.

any ideas on any of this just curios how to use non stick tape, and if other stuff is like asbestos I'll pitch it.

 

It sounds like rubberized self fusing tape for high voltage up to ~600v, fairly common, but there may not be a use for it for general around the house jobs?
Max.

 

also found a few other odd rolls that are like black cloth with adhesive. they say electrical tape, but all tape I've ever seen is plastic/ rubber. Not sure if like asbestos and I should pitch or just something special, or old.

Back in the day, that was electrical tape. Now, it's mostly called friction tape and is used by plumbers to get a grip on decorative trim pipe. It's not asbestos.

And the spelling you are struggling with is "weird," not wired and not wiered.

 

Self amalgamating tape? Good for tennis racket and bicycle handles amongst other things.

 

I edit Wikipedia technical articles for fun, so I've gotten rather good at finding citations in old engineering books.

Here's a 94 year old book talking about friction tape and other tapes for electrical insulation, scanned and with pictures:

The Electric Journal, Volume 14, Number 5, May 1914
Westinghouse Club
Copyright 1917

Article: Insulating Tapes and Their Application, by Dean Harvey
Pages 173-176

http://books.google.com/books?id=CjAyAQAAMAAJ&dq="rubber tape" "friction tape"&pg=PA173


It's very interesting just from the historical perspective. Here's some of it:

"Cotton is the most widely used material for tape as it has good mechanical properties and is less expensive than other materials It is strong tough and flexible.

It is somewhat hygroscopic, and when used as insulation, is usually treated with varnish or with an impregnating material to prevent the absorption of moisture. This treatment may be given either before or after the tape is applied. When the untreated tape is used, the entire coil may be varnished or impregnated after being taped."

[...]

"Silk is stronger mechanically than cotton and is much more expensive. It is used in places the space is limited, or as a finishing covering for small where a fine finish desired. When dielectric strength is desired, the silk is usually varnished."

[...]

"Linen is sometimes used for tape in order to obtain the maximum amount of strength. Flax is the strongest of the vegetable fibers, and also has the maximum degree of absorption. On account of its high cost, linen tape is rarely used, as under ordinary conditions cotton tape is considered satisfactory."


"Asbestos is the only material that will withstand high temperatures and can be woven into tape. On account of its low mechanical strength and its high cost, it is used only in places where other materials cannot be used on account of the high temperatures. It has a greater variation in thickness than cotton tape. In order to increase its mechanical strength, asbestos tape is sometimes made up with a small proportion of cotton fiber."

[...]

"Mica tape is made by mounting mica splittings on a backing of Japanese paper and then cutting the sheets into narrow widths of tape. It is used to insulate coils in turbogenerators and other machines where the high temperatures obtained prevent the use of fabrics and where high dielectric strength is required."

[...]

"In making joints in rubber insulated wires or cables, a rubber tape, or splicing compound, as it is sometimes called, is used to complete the rubber insulation, and is covered with a wrapping of friction tape for mechanical protection.

Rubber tape consists of a partially vulcanized rubber compound and is made in several grades. The tape should have sufficient strength to allow it to be readily applied without pulling apart, but the vulcanization should not be carried far enough to prevent the layers of the tape from fusing together when heated after being applied to the joint.

Its fusing ability may be determined by wrapping a sample on a rod of about one fourth inch diameter to a thickness of one fourth inch and heating it to a temperature of 65 degrees C (150 degrees F) for twenty minutes in an oven. The tape should fuse into a practically homogeneous mass."


"Friction tape is composed of cotton cloth impregnated with an adhesive insulating compound. The cotton fabric should be closely woven, smooth and strong, and practically free from knots or other injurious defects. The composition of the insulating compound varies considerably with different grades of tape. In general, it consists of rubber mixed with asphalt materials and non conducting mineral fillers."

[...]

It goes on to discuss testing tape for durability and longevity, and methods used for high-speed automated wrapping of coils with insulating tape.

(You could spend all day just reading about historical electronics in this book.)

 

The vulcanizing tape I've used has typically been very stretchy and it actually fuzes together with time at room temps, and pretty quickly too. It has a paper layer separating tape layers on the roll. We use it a lot as build-up tape for our cable backshells

 

ok thanks for info. pretty interesting how it's changed over time. I have a lot of different types from boxes of electronics stuff I've grabbed cheap at yard sales, etc. A lot of it I don't use much though because kind of odd. some rolls are normal size, but fairly thick I think for HV, or splicing. some others are similar, but wider. I think I have one roll that is like 6 in wide. I also got some newer scotch brand that looks like normal, but colored, and supposedly fire resistant.
have quite a few rolls that aren't UL marked I just use for low V projects. if fixing something like lines voltage then use the UL stuff. Not sure much difference, but better safe than sorry. =)