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Old 05-04-2014, 01:07 PM
Join Date: Aug 2000
Location: Parts Unknown
Posts: 2,748
Duct tape--safe to use as electrical tape?

My wife vacuumed the cord to the vacuum cleaner and it got chewed up pretty good. Didn't have any electrical tape, wrapped the cord with duct tape? Is that safe? Should I take the vacuum in to have the cord replaced right away or can we continue to use the vacuum without fear of something untoward happening?

As you probably can tell, I have no clue about things electrical. Thanks.
Old 05-04-2014, 01:11 PM
Join Date: May 2001
Location: Scottsdale, more-or-less
Posts: 15,609
Duct tape is non-conductive, so you don't have to worry about that.
Are the inner conductors OK? If it's just the outer sheath that's ripped, tape will protect it for awhile (duct tape isn't really very strong, so it won't last a long time).
If the insulation on the conductors is nicked, I'd get the cord replaced, or spliced by someone who knows what they are doing (heat shrink tubing is the correct thing to use).
Old 05-04-2014, 01:13 PM
Join Date: Aug 2000
Location: Parts Unknown
Posts: 2,748
Thanks, beowulff. Don't know about the conductors, so I'll get it replaced just to be safe.
Old 05-04-2014, 01:46 PM
Join Date: Jul 2009
Posts: 12,056
the cord takes a beating with a power beater head.

if the machine has a retractable cord then a good repair with electrical vinyl tape may interfere with the retraction.

if the inner conductor wires don't have broken insulation then duct tape may work for a while. though if it got chewed in a power head then wires inside could be broken as well.
Old 05-04-2014, 02:27 PM
Join Date: Oct 2009
Posts: 4,169
I'd get the cord replaced by a qualified repairman.

Expedients are rarely good enough when dealing with electricity. Plus they look annoying after a while.
The efficiency and success of the Italian aviators in Tripoli are noteworthy, but must not be overvalued. There were no opponents in the air.

v. Bernhardi ---- Germany and the Next War
Old 05-05-2014, 01:53 AM
Join Date: Apr 2003
Posts: 763
It's about the dielectric breakdown voltage of the material. Just because duct-tape is non-conductive means that it will stop you from becoming electrocuted if you touch the hot and ground at the same time. The voltage may bridge the duct-tape material and then... ZAP!

Usually, cords have two layers, the outer external one for abrasion resistance. The inner conductors will each have their own insulator and there should be a rating on it. Like 600V 50C, etc. Which means it was tested at 600V at that temp. The current rating is actually a combination of the wire gauge and the temp of the insulator. So, you can see various wire gauges for the same current but have a different temp on them. That's for in-wall, or within an electrical cabinet, etc.
Old 05-05-2014, 02:14 PM
Join Date: Jul 2012
Location: Durham, NC
Posts: 4,086
On a tangent, this reminds me of some dumb things done by a really smart guy. A co-worker of mine was doing research on what kinds of diagnostics a car's engine computer could do, back in the late 70's. They used an LSI-11-based computer in the trunk of the car, in lieu of the electronic engine control computer, because it was easier to reprogram and didn't have a lot of limitations that the EECs of that time had. This was a single-board computer, in a chassis with other boards for I/O and other features. He kept having board failures, which he had reason to believe to have been caused by boards scraping as they were removed and inserted (which they did a lot).

One attempt to solve this involved duct-taping the back (circuit side) of the cards. He ruined a few cards this way. Evidently duct tape isn't as good an insulator as it needs to be.

Second attempt was even funnier: he epoxied the backs of the cards.

Result: curved boards. Epoxy shrinks! Expensive lesson. The cards looked very amusing, to those of us who didn't need them.

Last edited by Learjeff; 05-05-2014 at 02:15 PM.
Old 05-05-2014, 08:01 PM
Join Date: Apr 2013
Posts: 6,726
I recommend you bite the bullet and replace the cord.
Old 05-05-2014, 09:01 PM
Join Date: Apr 2003
Location: Dayton Ohio USA
Posts: 27,503
duct tape does not age well. Not sure of it's non-conductive rating. Probably better than nothing until you properly repair or replace the wire. When replacing the wire make sure there is a good transitional boot going through the case or you'll be asking this question again down the road. Vacuum cleaner cords get a lot of flexing.
Old 05-06-2014, 12:48 AM
Join Date: Sep 2003
Location: Calgary
Posts: 1,142
I would not use duct tape except for an emergency short term fix. It doesn't age well as already mentioned, it makes a mess, and I personally am not going to trust it to properly isolate me from a shock hazard.

When a cord gets cut on the jobsite I do not repair it with electrical tape, those repairs never last and snag on everything. I cut it at the damage and either replace the plug or open whatever it belongs to reattach the shortened cord or a new replacement. An appropriate extension cord of similar gauge works fine. Power cords are usually just attached with a clamp for strain relief and screw terminals for the wires.

If you are not comfortable with taking fiddly plastic casing apart and stripping and attaching wires I would take it to the vacuum guy down the street. If you are talking about one with a self retracting cord it is definitely a job for vacuum guy.
Old 05-06-2014, 05:01 AM
Join Date: Jan 2013
Location: Worcestershire UK
Posts: 5,962
Depending how old the machine is - you may find that replacing it is more cost-effective than paying to have it repaired.
Old 05-06-2014, 01:05 PM
Join Date: Jan 2010
Location: East TN Mtns USA,NA,Sol3
Posts: 4,101
<hijack> Funny how we still have 'vacuum guys' down the street but no TV repairmen. </hijack>

And yes, duct tape will work OK for a temp fix, but it is a mess to deal with. Get a real fix soon.
Old 05-06-2014, 01:09 PM
Join Date: May 2011
Location: Midwest USA
Posts: 1,799
Not a good idea.

While duct tape can be non-conductive, it is a poor insulator. It’s just as cheap and easy to down to your local discount or hardware store and pick up a cheap roll of black electrical tape. Or better…. to simply replace the cord.

It’s two or three wires and adding a connecter to the end.
Total repair time: 15-30 minutes.
Old 05-06-2014, 01:38 PM
Charter Member
Join Date: May 2000
Location: Lincoln, IL
Posts: 25,174
Well, geez. I always thought duct tape could fix anything.
Old 05-07-2014, 05:39 AM
Join Date: Apr 1999
Location: Ohio
Posts: 10,795
Electrical tape must meet certain specifications.

Duct tape is not required to meet these specs.

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