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Sat Apr 10, 2021 12:02 pm

Yes, I know it's Arizona, and it's hot here. But can anyone explain why this happens to electrical tape here??? I can't Google this because I don't know what this is called.

Sat Apr 10, 2021 12:29 pm

It happens here too, I figured moisture expanding the inner roll may have played a part, there goes that theory. Old adhesive breaking down combined with shrinkage of the vinyl I guess.

Sat Apr 10, 2021 4:34 pm

And this is why electrical tape is not a permanent solution. Think of it as a band aid. Says the guy who works on electrical equipment that is mounted outside in the elements.

Sat Apr 10, 2021 4:58 pm

This is probably being stored incorrectly on a nail in the garage. I would think extreme heat would contribute to the tape curling up like that, it’s been warm in Phoenix recently yes?

Another factor is brand, some brands seem to perform better over time. What I’m using is a tape called Temflex made by Minnesota Mining and Manufacturing Co. I wouldn’t normally buy something like this but.

On it being a temporary repair all of the old cars used electrical tape from the factory, guess it would last till car payments were done.

Sat Apr 10, 2021 7:49 pm

Dang, I have not seen 3M written in its original form in a long time. Grew up in a MN town with a large tape plant, less than a mile down the hill from our house.

I will be calling my folks tomorrow. My dad knows a bunch of retired 3M workers and engineers. I will see if he can ask them for an answer to this question, as I have had it happen, too. And I have never lived south of Big Sky, MT.

Sun Apr 11, 2021 2:32 am

I wonder if the stuff has a 'grain' or bias that causes it to expand and contract differently along one edge compared to the other?

Heating and cooling cycles might cause it move in one direction more than the other with the glue acting like a lubricant when hot and fixing it in place when it cools, so it piles up like that?

Sun Apr 11, 2021 6:59 am

Zundfolge1432 wrote: This is probably being stored incorrectly on a nail in the garage.
In the garage, but not hanging.

Zundfolge1432 wrote: it’s been warm in Phoenix recently yes?
Yes - since the last Ice Age !!!

Sun Apr 11, 2021 7:02 am

This thread made me think of the old RAMVA days and so I checked and it is still there

https://groups.google.com/g/rec.autos.makers.vw.aircooled

Sun Apr 11, 2021 7:48 am

I think mrs cusser has been trying to fix the shelves in the fridge/freezer with it! :lol:

Sun Apr 11, 2021 10:38 am

turner over. :shock:

Sun Apr 11, 2021 4:11 pm

mark tucker wrote: turner over. :shock:

No sex talk on this site !!!

Sun Apr 11, 2021 7:05 pm

You are the one who posted about a hole with sticky edges. :-k

Sun Apr 11, 2021 7:19 pm

Now Cusser, there is a point in a little tapes life when it begins to experience changes. These changes may seem weird but are perfectly normal.

But in this case its totally weird, such a freak. Really though we see electrical tape do this in Texas too. From work we see trucks come in with tape everywhere, When used on the chassis it still sticks well and lasts a good while. In the engine compartment it appears larger and almost swelled up. So I'm no scientist and I have self respect so I'm not a engineer either, so our guess is the plastic tape expands and on a roll follows the path of least resistance thus pushing one side out. I feel like if it where the glue expanding it would just ooze out.

Or maybe they are just excited to see you

Mon Apr 12, 2021 2:21 am

I switched to Tesa brand wiring loom tape because I got tired of sticky rolls of regular electrical tape and I wanted to use what the OEM European manufacturers used on my bikes and cars. This stuff is made for high heat application and performs pretty well when handled correctly. It’ll definitely loose some adhesion if handled with sweaty hands at the ends. Scissors are also required to snip the length desired.

https://www.amazon.com/gp/product/B016ZMXLEI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Tue Apr 13, 2021 12:38 pm

It's just gravity in action. Heat makes the glue (a sticky semi-fluid) less sticky and more fluid. The coils of tape will start sliding downhill. Tape stored flat on a horizontal surface does not do that. I have twenty-year old rolls of electrical tape in my toolbox, only the rolls that got dislodged and lay at an angle show any departure from flatness.

Tue Apr 13, 2021 8:17 pm

I thought that too but Ive had some that were flat and did it.I figured the outer portion was tightening up or the center was swelling thus forcing the tape to go somehwere...probably the center absorbing some moisrture and swelling along with a heat sorce weather sun it whatever and time. it seems many tapes get liquider the older they get.I thinks it's the rubber/plastic affecting the addhivsive and liquidfiying it. or just time it's self and the addhivisive breakdancing down and liquidfiying.possiably another could be the moons phase when it's in the orbit of chewing gum softening the gummy addhivsive till it's more like the dog drewuel from pluto. either way I hate effing with a wireing harness thats got degrading tape, that slimey shit gets everywhere and a booger to screw with and retape with new tape.I dont think the fabrick tape does it, but it can dry out...witch starts another issue when jupiter is in retrograde........ :-k where is that emogie of somebody beating thier dead horse :?: :popcorn: [-X :!:

Wed Apr 14, 2021 4:21 am

It’s temperature shrinking the tape and pushing the roll up to relieve the pressure

If you store it cool, it won’t happen.

Wed Apr 14, 2021 6:33 am

Abscate wrote: If you store it cool, it won’t happen.
Well, that can't happen in Arizona !!!

Wed Apr 14, 2021 7:08 am

Abscate is pretty close. He got half of it! There are two items at play here. Get there in a minute.

About 90% of electrical tape made is vinyl. Vinyl is insidious crap .....but sometimes useful....crap. Some hugh end tapes like class H are made of fiberglass cloth.

I see people trying to use vinyl for things they want a permanent solution for.....and the fact they are using vinyl 100% guarantees its temporary.

Vinyl begins outgassing solvents ....and therefore shrinking ....and eventually hardening up when there are no more plasticizers to make it pliable.....the very minute its cast, molded or extruded. Long term parts like fender beading :roll: are made of vinyl....and therefore guaranteed to shrink and distort.

So....the two issues:

1. Its vinyl.....so it naturally shrinks.....and as abscate noted.....squeezes the roll and csn eventually pump out the core.

KEY TO REMEMBER: the plasticizers that are outgassed by vinyl.....are SOLVENTS....VOC's

2. The adhesive on basic, cheap vinyl electrical tapes are rubber based.....either natural or synthetic. The rubber is dissolved in a very low flash point, fast evaporating solvent like methylene chloride (low corrosive) or ethyl acetate (eventually will become corrosive).....and then roll or slot-die coated onto wide sheets of vinyl .....and dried in an explosion proof oven.....and then rolled up into one big wide roll (may be upwards to 144" wide).....and sliced into narrow rolls.

The problems this causes:

The problem is that as you roll materials like this.....as the roll grows in diameter....the roll tension needs to be reduced as you go. This is hard to control. The material near the inner core is under more tension.....which = more compression, twist and shear. So thats an initial problem.

The next big problem is that the rubber in the adhesive....readily absorbs and dissolves in solvent. And.....REMEMBER.....vinyl outgasses solvents. And....vinyl accelerates ots outgassing of solvents.....with heat!

So the adhesive is "re-wetting" from the solvents comi ng out of the vinyl.....and getting "slimy" and starting to FLOW.......and.....between the shrinking of the vinyl.....and the excessive pressure/tension down near the core.....it can pump the core right out.

BETTER electrical tape....even made with vinyl material......will use an ACRYLIC adhesive. But acrylic adhesive has less initial tackiness so it has to be used more carefully....and....eventually....acrylic based adhesives as they age....will become permanent and you will have a very hard time getting them off.

This page has a good comparison chart of the three main adhesive types used on electrical tapes and their pros and cons.

https://www.can-dotape.com/adhesive-tape-consultant/adhesives-used-for-tape/

Yes.....the tape manufacturing industry and the methods they use for toll coating are part of my industry.

Ray

Wed Apr 14, 2021 2:16 pm

raygreenwood wrote: Abscate is pretty close. He got half of it! There are two items at play here. Get there in a minute.

About 90% of electrical tape made is vinyl. Vinyl is insidious crap .....but sometimes useful....crap. Some hugh end tapes like class H are made of fiberglass cloth.

I see people trying to use vinyl for things they want a permanent solution for.....and the fact they are using vinyl 100% guarantees its temporary.

Vinyl begins outgassing solvents ....and therefore shrinking ....and eventually hardening up when there are no more plasticizers to make it pliable.....the very minute its cast, molded or extruded. Long term parts like fender beading :roll: are made of vinyl....and therefore guaranteed to shrink and distort.

So....the two issues:

1. Its vinyl.....so it naturally shrinks.....and as abscate noted.....squeezes the roll and csn eventually pump out the core.

KEY TO REMEMBER: the plasticizers that are outgassed by vinyl.....are SOLVENTS....VOC's

2. The adhesive on basic, cheap vinyl electrical tapes are rubber based.....either natural or synthetic. The rubber is dissolved in a very low flash point, fast evaporating solvent like methylene chloride (low corrosive) or ethyl acetate (eventually will become corrosive).....and then roll or slot-die coated onto wide sheets of vinyl .....and dried in an explosion proof oven.....and then rolled up into one big wide roll (may be upwards to 144" wide).....and sliced into narrow rolls.

The problems this causes:

The problem is that as you roll materials like this.....as the roll grows in diameter....the roll tension needs to be reduced as you go. This is hard to control. The material near the inner core is under more tension.....which = more compression, twist and shear. So thats an initial problem.

The next big problem is that the rubber in the adhesive....readily absorbs and dissolves in solvent. And.....REMEMBER.....vinyl outgasses solvents. And....vinyl accelerates ots outgassing of solvents.....with heat!

So the adhesive is "re-wetting" from the solvents comi ng out of the vinyl.....and getting "slimy" and starting to FLOW.......and.....between the shrinking of the vinyl.....and the excessive pressure/tension down near the core.....it can pump the core right out.

BETTER electrical tape....even made with vinyl material......will use an ACRYLIC adhesive. But acrylic adhesive has less initial tackiness so it has to be used more carefully....and....eventually....acrylic based adhesives as they age....will become permanent and you will have a very hard time getting them off.

This page has a good comparison chart of the three main adhesive types used on electrical tapes and their pros and cons.

https://www.can-dotape.com/adhesive-tape-consultant/adhesives-used-for-tape/

Yes.....the tape manufacturing industry and the methods they use for toll coating are part of my industry.

Ray

That's why we keep our roll stock in a humidity controlled room, we even keep some in a refrigerator so the adhesive doesn't seep out while being printed on.