What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Lacing Cord

BoilermakerRV

BoilermakerRV

Well Known Member
I'm preparing to do my first round of wiring in my wing (pitot heat, wing tip lighting). I've chosen to use lacing cord as opposed to zip ties, but I'm having trouble identifying the correct product to use. All the products I found on Aircraft Spruce's website talk about rib lacing, which I don't believe is the same thing. However, I recognize that the rib lacing cord may also be usable for wire bundling. Thoughts on round/flat or waxed/non-waxed?

Thanks!
 
I used flat waxed.

P5110057.jpg
 
knotty question

Couple years back Kitplanes (I think) showed pictures of how to tie a nice tight knot with that cord. Can anyone point me to an illustrated how-to?
 
dlloyd3 said:
Couple years back Kitplanes (I think) showed pictures of how to tie a nice tight knot with that cord. Can anyone point me to an illustrated how-to?
Click to expand...

Click on the link in Gil's post above.

Clove hitch, and square knot.
 
Some years ago at a "how to" class, I was shown a different knot than mentioned so far in this thread. It allows one to do the individual knotted laces without having to cut an individual string first. You cut after the knot is finished and move on. Saves big time on wasted thread and mess. (like that matters) :rolleyes:

This allows the roll to be on the floor, line in left hand continuously, dikes in the right and knots being made and trimmed quicky. It was competitive with zip ties for ease.

Verbal description is outside my skill so I will try to find some images somewhere.
 
rzbill said:
Some years ago at a "how to" class, I was shown a different knot than mentioned so far in this thread. It allows one to do the individual knotted laces without having to cut an individual string first. You cut after the knot is finished and move on. Saves big time on wasted thread and mess. (like that matters) :rolleyes:

This allows the roll to be on the floor, line in left hand continuously, dikes in the right and knots being made and trimmed quicky. It was competitive with zip ties for ease.

Verbal description is outside my skill so I will try to find some images somewhere.
Click to expand...

Could it be the simple clove hitch shown of page 2 of this NASA document?

http://www.sandman.com/files/NASAcable lacing40-43.pdf

You could get the basic knot going with the reel on the floor, and then cut it and do the square knot...
 
az_gila said:
Could it be the simple clove hitch shown of page 2 of this NASA document?

http://www.sandman.com/files/NASAcable lacing40-43.pdf

You could get the basic knot going with the reel on the floor, and then cut it and do the square knot...
Click to expand...

Gil,
It is kinda like a clove hitch that is finished with what I think is called a double overhand (a single overhand with another wrap) . The trick was that you form a couple of loops, pass the raw end though one loop, tighten and then do the double overhand with the raw end. All of this without cutting the cord from the reel.

I looked for some images on the web but can't find any. I still have the printouts from that class so I can scan and post later. I know the knot does not conform to 43-13 but I believed the old guy and the knots are definitely secure.

EDIT: It looks like a variation of the closing stitch shown in figure 9-4
 
Last edited:
Great "thread" !

Timely topic ; . . . a bunch of us must be at the same point. I just researched this last night and ordered my lacing today. Good references here, the same ones I found, and read. Great forum for builders!
 
To save some time put your bundle together with Ty wraps and leave them loose to put in the extra wires you may have forgotten. After it is all done use the lacing cord to finish the job and remove the Ty wraps.
 
longranger said:
The illustrations in that reference look similar to those in AC-43.13, my go-to reference. Electrical is Chapter 11.
Click to expand...

That makes sense, considering the harness tying techniques go back to before the FAA was created...:)

The FAA shows the clove hitch plus square knot method for a spot tie, but the easy AeroElectric Bob method is not shown in any other links.

I find Bobs method easier to in a confined space.

http://www.aeroelectric.com/articles/cable_lace/cable_lace.html

It's been a long time since I did knots in the Boy Scouts....:)
 
Wax on/wax off

Without knowing the difference between the waxed/unwaxed, I purchased the unwaxed (it was slightly cheaper). The unwaxed is rather slippery and in my experience knots tended to loosen if they were not pulled extremely tight, which can be hard to do in confined spaces and I didn't want to cause the insulation to flow from a Vulcan death grip. I purchased a roll of the waxed and find it much easier to use: knots stay knotted, and you don't need to use an immoderate amount of force to tie them. They also look cleaner - no "bowties" - since you can clip the loose ends to 1/4" and then smooth them back around the lace - the wax will "bond" to itself. If you are using Nuckoll's guide, you'll make a loop in the end through which you pass the loose ends after doing the wrap - with waxed lace you can make this loop and pinch it and the wax will hold the loop for you. The unwaxed didn't do this and made the job a bit more difficult in tight spaces. The above explanation will make sense once you start your lacing.

On a related note (neat installation of wiring bundles) check out Waytek's online catalog. They have a very nice assortment of plastic clips, heat shrink, high temp zip ties etc. Stein pointed me in their direction.
Eric
 
Waxed

Definitely waxed for harness ties. The wax keeps the knots from possibly slipping.

The Spruce link I gave earlier only covers waxed cord in their electrical section, and AeroElectric Bobs notes prefer polyester over nylon.
 
az_gila said:
I find Bobs method easier to in a confined space.

http://www.aeroelectric.com/articles/cable_lace/cable_lace.html

It's been a long time since I did knots in the Boy Scouts....:)
Click to expand...

In Bob's Method 2, the square knot doesn't secure anything. It only acts as a stopper. What you need to do is take one of the laces all around the bundle and then make the square knot. Otherwise it'll just pull through the loop.

Hate to be picky but we need to watch what we're doing.

Dave
 
David Paule said:
In Bob's Method 2, the square knot doesn't secure anything. It only acts as a stopper. What you need to do is take one of the laces all around the bundle and then make the square knot. Otherwise it'll just pull through the loop.

Hate to be picky but we need to watch what we're doing.

Dave
Click to expand...

I think this is where the waxed finish comes into play.

When the ends are pulled tight per Bobs instructions I have not been able to get one to come apart. The "stopper" works.

PS being picky is good...:)
 
Last edited:
az_gila said:
I think this is where the waxed finish comes into play.

When the ends are pulled tight per Bobs instructions I have not been able to get one to come apart. The "stopper" works.
Click to expand...

Yep, when you pull the bitter end the Larks head grips the lace, and the harder you pull, the tighter it grips. The square knot just keeps the whole thing tight.
 
I am sitting here at the office after having slaved like crazy this week to get everything done so I could comfortably scat to SnF next week. Well, I got done a few hrs early and decided to try to sketch this lace knot I was talking about and get it into a Jpeg.

The images may not transfer how easy this is to tie. Steps 1 2 3 can be done in about 2 seconds with your thumb and forefinger. Snug it down and then add the top knot at liesure because the wires are held with the initial snug loops. Maybe this is a chance for me to learn how to post a YouTube.

As said earlier, it is not AC43.13 but I am very satisfied with the security.

1883057634515f106405e7a.jpg


1727233231515f10640aca2.jpg
 
rzbill said:
I am sitting here at the office after having slaved like crazy this week to get everything done so I could comfortably scat to SnF next week. Well, I got done a few hrs early and decided to try to sketch this lace knot I was talking about and get it into a Jpeg.

The images may not transfer how easy this is to tie. Steps 1 2 3 can be done in about 2 seconds with your thumb and forefinger. Snug it down and then add the top knot at liesure because the wires are held with the initial snug loops. Maybe this is a chance for me to learn how to post a YouTube.

As said earlier, it is not AC43.13 but I am very satisfied with the security.

<snip>
Click to expand...

Looks good... I'm trying to work out what happens.

Does pulling the short end under the loop in step 3 make the basic knot into a clove hitch?
 
Gil,
Its not as clean as a clove hitch. I never have figured out what "classical" knot it is. (and I have Ashleys book ;)) In a way it is good because even though it takes a few more "jiggles" to get all the slack out, it stays put better than a clove while you tie the finish.

Just to give an admission, I know I have put the raw end through the loop in step 3 from either direction. The bottom as shown and sometimes from the top . It made no discernable difference while I was hanging upside down under the panel :)
 
knotty situation

For those who think tie wraps may be easier, me too at first. Did not understand why people complained about the sharp cut off ends. I think cut off tie wraps become harder, pointer and sharper with time. When you are building, you have more room to avoid the sharps. Once completed, there is little wiggle room and you will shread your arms. Compared to metal burrs and safety wire, it is a couple drops of blood compared to a pint. For the last year, every time I make a wiring change (and you will make many), I do not cut the tie wrap knowing it would cut me before being replace with lacing. Since under my panel is beginning to look like some strange catus garden, it must be time to start lacing. Maybe after wiring that starter engaged light.
 
Alternative to Lacing and Cable Ties.

Hello Gentlemen (Ladies)

About 2-3 years ago on a TV programme called Dragons Den here in the UK a entrepreneur invented an alternative to cable ties. It's since taken Europe by storm.

The 'rapstrap' is soft, flexible, reuseable, and has no wastage, in my view a much easier alternative for those of us that never joined the scouts or are sailors!

Give this site a visit and watch the video. http://www.rapstrap.com/how-it-works

David
 
The perferct knot

A very secure method of tying a knot in slippery materials such as the waxed flat material from ACS is:

place three throws initially-tighten
follow with two throws-tighten
secure with an additional single throw-tighten

The three followed by two throws secures the wires in a snug fashion. The third throw locks the process. With minimal practice, this should give great results. In 40 years of surgical practice primarily with polypropylene sutures, this is a most reliable method.
 
Greg Baron said:
A very secure method of tying a knot in slippery materials such as the waxed flat material from ACS is:

place three throws initially-tighten
follow with two throws-tighten
secure with an additional single throw-tighten

The three followed by two throws secures the wires in a snug fashion. The third throw locks the process. With minimal practice, this should give great results. In 40 years of surgical practice primarily with polypropylene sutures, this is a most reliable method.
Click to expand...

I've seen guys do that almost as quickly as someone with zip ties! Also, 'lectric Bob's quick method works perfectly if done properly, as do many of the other knots shown.....in fact, almost all are faster than the old Clove hitch yet equally secure. With a bit of practice, almost any of the aformentioned methods will work and be just as fast as Zip-ties, and won't slice up your hands later. If you walk through my shop, you'll likely see various techs using any number of the noted knots.

Also, if you use Zipties and we work on your airplane later, I'll charge you a "tax" for doing so! :)

Cheers,
Stein
 
My guess...

rzbill said:
Gil,
Its not as clean as a clove hitch. I never have figured out what "classical" knot it is. (and I have Ashleys book ;)) In a way it is good because even though it takes a few more "jiggles" to get all the slack out, it stays put better than a clove while you tie the finish.

Just to give an admission, I know I have put the raw end through the loop in step 3 from either direction. The bottom as shown and sometimes from the top . It made no discernable difference while I was hanging upside down under the panel :)
Click to expand...

I am an Eagle Scout, but it's been a long time since I knew my knots well. I'm thinking your knot is basically a version of a timber hitch, which can be made with the side loops like you show. It's a great knot for lashing wooden poles together to build towers. :D
 
The Wizzard said:
Those grommets look interesting where did you get them?
Click to expand...

Since I posted the only photo with any grommets in it, I will assume your question is directed to me.

There are at least 3 different items in the photo that you could be talking about, snap bushings in the small holes in the tunnel and elsewhere, caterpillar grommet in the large hole upper right, and the three that I suspect you are talking about are in the middle behind the wiring. They are actually from the aviation aisle at Lowes or Home Depot. They are used in electrical boxes when you knock out a hole for conduit, and use a threaded adapter. They screw on over the exposed threads. If you look carefully, you will see a bit of blue "Smurf" flexible conduit in them. Runs under the baggage floor to the battery area. Strobe power pack also in that area. Center is a spare.

Hope this helps.

P5110057.jpg
 
Nomex cord

Another option to those who do not like to use zip ties for high temp areas such as forward of the firewall is a Nomex lacing cord. It is rated to 500F. When I was at the airlines we called it "salt and pepper" cord as it is white with black tracers.
 
Grommets

Mike, yes the question was answered right! I thought that those came from the aviation Isle. Great idea, one I had not thought about!

Thanks,

Dave
 
I tracked this down a while ago in prep for some lacing work. I've seen satellite technicians to an *amazing* job lacing cables ... and I'd like to bring some of that craftsmanship to my bird.

However, this pic came from an old Popular Mechanics mag ... I think it was an original reference for Wilbur and Orville..

2en16s7.jpg
 
Hi All,

As a long time lurker I'm over due for my initial post.

Having wired everything from Jabirus to Jumbos I'm a big fan of waxed flat lacing cord. Using a clove hitch with a square knot provides a simple and secure method securing most wiring.

For FWF or other high temp areas there is high temp lacing cord available but use a double knot to secure.

With practice, lacing cord becomes as easy to use as zip ties without the blood. I'm with Stein when it comes to working on other peoples zip tie installs.

Cheers
L_Rocky
 
High temp?

Is the high temp cord nessessary for FWF? Whats the temp rating on zip ties anyway? I plan to use lacing cord and need to know if I need two kinds.
 
You'll be fine with standard lace chord unless you're putting a turbine in your RV :D
 
Last edited:
Moved the thread to "electrical"-----too much good info here to get lost in the "General discussion" section.

This should make it a lot easier to find in the future.
 
ILikePike said:
Is the high temp cord nessessary for FWF? Whats the temp rating on zip ties anyway? I plan to use lacing cord and need to know if I need two kinds.
Click to expand...

The nylon lacing is good for 250F and the polyester for 350F.

Polyester should be OK for most FWF locations if you keep away from the exhausts.

Your standard mil-spec /16 wire is only good to 305F anyway....:)
 
Last edited:
ILikePike said:
Is the high temp cord nessessary for FWF? Whats the temp rating on zip ties anyway? I plan to use lacing cord and need to know if I need two kinds.
Click to expand...

As Walt said, just buy the standard stuff and call it good. You spend your time quoting and or spec's ad nauseum....or you can go build the plane (this is what we call the difference between theorizing and building)! :)

Speaking from experience, Walt is correct, standard stuff is fine. No need to get lost in details when the "normal" stuff will work perfectly for most everything in our RV's.

Just my 2 cents as usual!

Cheers,
Stein
 
SteinAir said:
As Walt said, just buy the standard stuff and call it good. You spend your time quoting and or spec's ad nauseum....or you can go build the plane (this is what we call the difference between theorizing and building)! :)

Speaking from experience, Walt is correct, standard stuff is fine. No need to get lost in details when the "normal" stuff will work perfectly for most everything in our RV's.

Just my 2 cents as usual!

Cheers,
Stein
Click to expand...

Stein,

I agree, however in this case there are actually two standards if you buy from Aircraft Spruce.

If you are concerned about FWF temps then the cheaper "standard" polyester stuff is actually better....:)
 
Please excuse the slight hijack, but I am trying to find a source for mesh tubing I have seen used for harnesses. It has a fairly open mesh, is black in color, and seemed to have some "pull to shrink" capability. Any suggestions would be appreciated.

Stan
 
splevy said:
Please excuse the slight hijack, but I am trying to find a source for mesh tubing I have seen used for harnesses. It has a fairly open mesh, is black in color, and seemed to have some "pull to shrink" capability. Any suggestions would be appreciated.

Stan
Click to expand...

We stock a standard size that works for most all of your needs.. You'll see it on a lot of harnesses we build (kind of like lacing cord, believe me and Walt when we say the "standard" black stuff works fine). It goes by the name of expandable tubing or sleeve....otherwise known as "snakeskin".

Cheers,
Stein
 
Last edited:
You must log in or register to reply here.
Back
Top