The image kind of says it all. Just hold the two cords together, tie them in a simple overhand knot, then plug in the ends. The benefit of the method pictured at top — as opposed to the common alternative pictured at right — is that when you inevitably apply some tension to the knot, the strain is diffused by your knot and not placed on your plug connectors (which means less chance of shorting your connectors).
While you’re polishing up your cord-knotting skills, check out how to use a daisy-chain knot to resize or store spare cords without the clutter.
Power Tool Cord Tip [A Concord Carpenter via Reddit]
Travis
Thursday, August 25, 2011 at 10:39 AMThat old article about Daisy Chaining knots has a non-existant video.
Rob
Thursday, August 25, 2011 at 7:43 PMUse the 2nd method myself, but will try method 1 – although extension cords do come with the warning to use them uncurled (and therefore not knotted either). When too much power is drawn (could be a problem when using lots of cables strung together and using a high power tool), the cables do warm up. Think of jumper leads getting hot when you use them. But if they get that hot to melt the insulation then there is a real problem, knotted or not.
Shaun
Thursday, August 25, 2011 at 8:57 PMYeh my science teacher would always unspool the rather long overhead projector power cord before plugging it in. I was curious as none of the other teachers did this, and she said she did it cause it uses a lot of power causing the cord to heat up which can be a fire risk.
As long as the knot is loose I can’t see it being a problem as power-cords run over the top of themselves all the time. If it it was like a 50m cord all spooled up in cardboard box plugged in and drawing a high load then I’d be a bit worried.
potts
Friday, August 26, 2011 at 10:22 AMit’s funny, because the first thing i was taught as part of my electronics course was to never use a cord when it’s coiled or knotted…
The Saint
Saturday, August 27, 2011 at 4:14 PMNO, dont do this. Again I have to raise the importance of MBR-Minimum bend radius.
The Saint
Saturday, August 27, 2011 at 4:15 PM“Figure eighting” is the only way to coil powered cables.