Not really electrical per se but I was helping a friend do some work at his house – about 50 – 60 years old. We changed some wiring and the old electrical tape left this rubbery gooey mess on the wires – cloth braid covered no less. Question 1 – how do you get this stuff off the wires and off your hands? Question 2 – what the heck happens to old electrical tape that causes it to become the most foul sticky mess? Is it just time or is it crappy adhesive? I only use Scotch 33 tape since I found the $0.99 hardware store type is terrible. Will the “good stuff” do this in 50 years as well?
I ended up using like 5 different cleaners on my fingers and finally used the good old comet and a scrub brush. This is not the first time I noticed this just the most recent.
Thanks for the input.
Replies
Chris,
That old tape is nothing but unvulcanized, natural rubber. No adhesive. What causes it to deterioriate? Heat from normal resistance heating of the wire, or heat in the attic, air pollution (ozone), other stuff (for instance, rat pee :-0).
Ya, cheap electrical tape is, well, cheap. I use 33+ (or 88, which is more than twice as thick as 33+) for insulation purposes. The cheap stuff, I buy by the sleeve (10-pack), when fishing and pulling wires.
To get the crud from old rubber tape and wire insulation off my skin, I use a waterless handcleaner with pumice. Klein makes a good one, but any mechanics handcleaner--and a lot of scrubbing--will do it.
Old non-metallic cable--the early stuff called loomex, with a cotton jacket that's impregnated with bitumen (basically, tar), really does gunk up your hands when you handle it. It's gotten to a point that I use nitrile gloves (medium thickness) when I'm working with loomex, and usually when I'm in an attic or crawlspace, as well.
The nitrile gloves last a lot longer than latex ones, save a lot of little cuts and nicks, and I don't have to remove the top layer of my skin to remove the tar.
Work safe,
Cliff
I like the glove idea for my hands but part of the problem was that whatever I touched turned black. Lucky for me the room was scheduled for painting this week.
On a similar note - when my grandfather, an electrican, would tape things he always used rubber tape and then covered it with friction tape. This was a sort of tough cloth type of material. I guess it would protect the rubber tape from abrasion. I don't know if they even sell this anymore. Has the rubber tape gotten so good or was the friction tape just overkill or do we not waste time with two layers anymore?
Also, has anyone tried those pushin connectors that are supposed to replace wire nuts? They were on some recessed fixtures that I installed recently and I saw them in bulk for purchase. I hope they are better than the stab - in connections on the cheapo receptacles they sell at the depot. I assume that they are UL listed if Halo uses them on their fixtures. Any thoughts. They seem much easier than trying to twist and cap 6 - #12 & #14 wires together. The most I have seen accept 6 wires but I understand that they are made for up to 8 wires.
Chris,Back in the day, all splices were wrapped in rubber tape, and then friction tape. The cloth-based friction tape was there for mechanical protection; it was the rubber tape that served as the electrical insulation.Yes, you can still get both rubber tape and friction tape.Good quality vinyl tape doesn't need any overwrap. Two things about using vinyl tape, if you pull the tape to break it off, that stretched-out tail won't adhere properly, and so the tape is on the way to unwrap itself, at least a little bit. So, cut the tape off the roll when you're wrapping splices or wires. When I'm using heavy tape to wrap conduit to be buried, I've used PVC cement to finish the wrap. Works great, as the tape itself is PVC. Not worth the hassle when doing splices, though.As far as the push-in connnectors (Ideal makes the "In-Sure" and WAGO the "Wallnut")--yes, they are a lot better than the poke-in backwire connections on receptacles and switches. I think they're not as good as a properly-applied, quality wirenut. I use the in-sure connectors for lighting work, connecting fixture wire to building wire, where the load is not heavy. And sometimes I use 'em in other situations where it's impossible to make a splice with a wirenut (like when the wires are too short, and the client just won't pay for running a new section of cable).I've seen entire houses wired with the in-sure connectors, and it'll be interesting to see if they hold up in circuits that see heavy current (bathroom receptacles, kitchen receptacles).Work safe, Cliff
I used some of those Ideal brand connectors this weekend and it was that typical short wire in the handybox (was wire so expensive that it would have killed someone to leave 2 -3 extra inches for the next guy) that would have required much swearing and many tries to get the wire nut on properly. With these I just pushed the wires in and was done. It also seems as though the fit in the box better due to the flat shape and the fact that you don't have a twisted, braided group of wires to deal with. I hope they prove out okay since they are not overly expensive and they do work well in certain instances.
Thanks for the info.
Everything deteriorates. As CAP pointed out heat, ozone, chemical contaminates speed this process. Electrical tape, at least the good stuff, has improved enough that IMHO if a mechanic does a good job and uses the proper tape fifty years is a reasonably conservative expectation.
I have seen 60 year old natural rubber insulation looking pretty much like it did when it was installed. It was still alive, flexible, relatively soft and resilient. Mind this was wiring that was under a house and so protected from heat and sunlight but the old rubber insulation was so quickly deteriorated that most was installed in a manner that the insulation was not vital to the systems integrity, knob-and-tube wiring.
Generally almost all the tape I use, mostly driven by availability, is made by 3M:
3M
The 1700 is good CBT, Cheap Black Tape, while Highland just a bit less good but still good enough for most non-electrical uses. The 1700 is mostly good enough for undemanding interior wiring situations in a box and the occasional correction of nicked insulation. Highland a bit less so.
Contrary to popular belief the majority of electrical tape used on a site is consumed on non-electrical tasks. Like bundling wires and cables for storage and temporary control, making small pulling heads and keeping the blood in the help.
1700 is the tape I hang off my pouch. If I'm buying for a pulling crew pulling wires into small conduit Highland can save a dollar or two as they are not insulating anything. Larger heads are made with a good quality duct tape. 1700 at about half the price of the higher grade stuff is a bargain. Highland even more. Though I have seen it at the big box at the same price.
Of course when the voltages get higher, the conditions more demanding and the consequences of the tape breaking down higher I use higher grade tape. My favorite Super33+. This I don't generally hang off my belt. The edges get dirty. That compromises the seal on splices.
Avoid no-name tapes. The adhesives bleed, soften and fail even without environmental factors. The plastic base often gets hard and brittle when cold and the adhesive useless in heat. Nothing like trying to wrap a spot when the entire roll unwinds twenty feet and lands at the foot of the ladder on a hot day.
You can get more out of any tape if you use it well. Like most better manufacturers 3M wants you to get the most of their products. They thoughtfully provide some good tips on selection and use on the page I linked to.
Wash your hands with WD-40 first. Use lots of it. Work it in well.
Dry them with a paper towel, so you can rub as much of the black stuff off as possible.
Now wash with Dawn dishwashing liquid.
Works equally well for that black grease you get all over you when you work on a car.
Are we there yet ?
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Napalm will take it off...
but try it first on an inconspicuous spot because you may find the excessive charring unattractive..."I think natural selection must have greatly rewarded the ability to reassure oneself in a crisis with complete bull$hit."
Witty tagline...
I don't like smelling like victory.
Are we there yet ?
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I don't know if it will remove the stuff you had on your hands but Avon Skin so Soft is great for removing tar. Plus it leaves your hands in great condition.
FWIW
In my own house at 120/240V nowadays i use the 20 cent HF stuff. For aircraft and spacecraft at work I use permacell stuff that is $45 or so a roll (polyimide with acrilic adhesive, sometimes with a polyamide backing). After using the HF 20 cent/roll stuff for 15 years or more, don't really see any substantial difference at normal room temp environments between that and scotch 33.
BTW: Scotch 33 is lots better to wrap ball batt handles with though, you dont get that "pine tar' between layer feel.
It seems to me that the scotch 33 always sticks and stretches nicely when wrapping bundles. The cheapo stuff is more hit or miss. What is the HF ? Is that a brand name? I would much rather use a less costly roll if it works. To me 3M makes the best products from electrical stuff to car polish but it seems like it is geared to the professional and they charge a premium for it. That said I guess you get what you pay for since scotch products have never let me down - except in the wallet.
Harbor Freight
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=6047
At the bottom of the above link they have "industrial grade" 20 rolls for 9.99. The 10 for 2.99 looks best. I have bought the same product at the travelling junk tool stores, (Homier, and others as well as Northern Hyd.).
Edited 7/19/2005 12:44 pm ET by RASCONC
and it'll keep the skeeters off yer peter!!"I think natural selection must have greatly rewarded the ability to reassure oneself in a crisis with complete bull$hit."
Witty tagline...