Wire lacing knots not holding

[Steve Crewdog]

Hi all,

Spent today lacing a run of wires together, got to a section that involved a curve and the tyes would not hold, almost immediately came undone. Went back over some of the tyes on the straight portion and some held, some didn't. I went back to the curve I had been working, did a few more and paid very careful attention to what I was doing (in case I was tired and getting sloppy), and they still came undone. Wondering if I trimmed the ends too close, or I'm tyeing them too tight, or...???

I'm using Method 2 as shown on the Aeroelectric Connection website, with waxed lacing cord. http://www.aeroelectric.com/articles...able_lace.html


Anyone else ran into this?


TIA

[PilotjohnS]

I dont use this method.but if the square knot is loosening, make sure you are doing a square knot and not a granny knot. On a square knot, the two ends that cross should come from the same side of the loop. A granny lnot has the two ends that cross perpendicular and not from the same side of the loop. Lastly, you could try a second twist on the cross over.

[Steve Crewdog]

I think you may be right, I looked at the failed knots and the main parts were still intact, leading me to believe that one piece of line was "slipping through" the knot. I was also thinking that I was accidentally tying 2 half hitches, which would leave one piece of lacing cord accidentally becoming a standing line, and allowing it to slip through.

[marchudson]

Page 11-63 of AC43.13 has some good examples of tying wire bundles. I also had to place an extra loop after tying the square knot because some of the ties showed signs of loosening.

https://www.faa.gov/documentlibrary/...-1b_w-chg1.pdf

If you want additional knot information. The Ashely book of knots is the bible of knot tying. https://archive.org/details/TheAshle.../n185/mode/2up.

We lived on a sailboat for a while and between that book and the live aboard community we learned a lot about tying knots.

[bobnoffs]

it's been my experience that after securing something it takes 3 half hitches to make the knot slipproof. i don't even think about it anymore, just tie 3 half hitches.

[Mike Buckler]

Easy video https://m.youtube.com/watch?v=CR3z5WZeHTw

[agirard7a]

From my sailing background, i have found this technique very easy and secure.
Only requires a three or four wraps. Very quick and easy. Dental floss works great in a pinch!

https://youtu.be/n2HFjSW37a8

[N804RV]

I've never used "method 2" . I've always used "method" 1, even on the biggest wire bundles.

Also, what kind of lacing are you using? My favorite is the Nomex lacing that my former employer uses. But, it can be hard to find. If you're using lacing that doesn't cinch down and tends to want to 'spring' apart before you tie the square knot, try something different.

The wax lacing cord that Steinair sells is easy to make nice neat wire bundles. Because it is waxed, it will hold some tension while you're tying the knot, making for a nice tight bundle. However, you need to wear something to protect your fingers. I used to tape the 1st knuckles on my index fingers to prevent the waxed lacing from sawing into the skin.

[wirejock]

I use the second method. You can cut wire with it. Never comes loose, but does requie a "square knot". Practice on shoe laces. A square knot will lay flat as tied. A "Granny" will rotate 90 degrees after releasing. Right over left, Left over right or whatever helps you remember.

[rmarshall234]

I've been using a Surgeon's knot like we do in the parachute rigging business along with waxed super tack nylon cord. Been working great for decades and I've never had a knot undue itself unless the waxed dried out or was subject to lots of abrasion. The "tail" should be trimmed to 1/4 inch.

https://en.wikipedia.org/wiki/Surgeon%27s_knot

http://www.paragear.com/skydiving/10...UPER-TACK-CORD