zip-ties

T

thito01

Pre-takeoff checklist
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Tony T
I know this may be a stupid question, but are there specific zip-ties to be used in aircraft? Or, can we go down to the local big-box and get some to use?
 
wax string...learn to tie wrap.


Zip ties should be banned by punishment of asset forfeiture.


If you must use zip ties, then pretty much any of them will work, if they aren't so old they break upon bending. Just be aware that they do chaff whatever they are securing, and the clipped ends exhibit a snag and cut hazard (although no more so than safety wire).

That said, these guys make a quality product that can be reused and doesn't chaff (...as much).
https://griplockties.com/
 
dtuuri said:
Kinda chafed me to read that. :)
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As it should. ;)

Much like to, too, two, break, brake, accept, except, affect and effect... we grammar masochists have much to relish with the current display of educational achievement.


Oh...thanks for noticing. :)
 
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aterry1067 said:
wax string...learn to tie wrap.


Zip ties should be banned by punishment of asset forfeiture.


If you must use zip ties, then pretty much any of them will work, if they aren't so old they break upon bending. Just be aware that they do chaff whatever they are securing, and the clipped ends exhibit a snag and cut hazard (although no more so than safety wire).

That said, these guys make a quality product that can be reused and doesn't chaff (...as much).
https://griplockties.com/
Click to expand...
Why do zip ties chafe more than anything else that serves the same purpose?
 
Lindberg said:
Why do zip ties chafe more than anything else that serves the same purpose?
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Because they are hard/stiff nylon chafing against soft rubber tube coating or PVC (or old capton) wire insulation.
 
You only get chafing where there is relative motion. So, if you've got a wire that connects to a sensor on the engine, use an adel clamp as the first attachment to the engine mount (or whatever fixed portion of the airframe you're hitting first). After that point, there is no relative movement between the wire and the hard point. You're fine to use zip ties in those downstream applications.
 
kyleb said:
You only get chafing where there is relative motion. So, if you've got a wire that connects to a sensor on the engine, use an adel clamp as the first attachment to the engine mount (or whatever fixed portion of the airframe you're hitting first). After that point, there is no relative movement between the wire and the hard point. You're fine to use zip ties in those downstream applications.
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This is pretty much true. And for GA, I agree. But, I've maintained supersonic aircraft for over 30 years, and I have yet to find any reference to acceptable zip ties. I completely understand that our aircraft are not exposed to such extremities.... just a force of habit, I guess.
 
Pratt uses them on some engines now. They’re spendy though, at several bucks each.
 
thito01 said:
I know this may be a stupid question, but are there specific zip-ties to be used in aircraft? Or, can we go down to the local big-box and get some to use?
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Technically they should be manufactured to some sort of industry standard to be considered FAA standard parts. But there are some milispecs and other aviation spec for some tywraps. For example engine comparment ones are to a certain mil-spec and are usually blue or purple in color.
 
With the original question, I was not thinking of the engine area, but instead, all the wire bundles though-out the cockpit, especially behind the panel.
 
thito01 said:
all the wire bundles though-out the cockpit, especially behind the panel.
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Per guidance all parts used on TC arcraft need to follow some sort of specification regardless of location. Is it enforced no. I use lacing cord on new installs and mil-spec tywraps on everything. One trick to using typwraps is use flush cut dykes to trim tabs as it leaves almost no knife edges.
 
On my plane, I think that I used one or two zip ties. And those were only in places that I just couldn't get to easily with lacing cord.

But if you must use zip ties, either get a quality tool for installing them or at least get some flush cut pliers.
 
Yes. All the complaints are eliminated. They will not cut through structures.

Rubber Lined, Releasable, Heavy-Duty Zip Ties, UV Rated, 8 Inch, Reusable, Black Nylon Zip Ties, Assorted Colors (Blue, Red, Orange) - GripLockTies (100, B
available at the 'Zon.
 
Zip ties being bad in an engine compartment is an old myth. There is nothing inherently bad about zip ties if properly used. Open the hood of your car and you will see them all over the place. Larger commercial jet engines even have them. The key is using them in the right application. Don’t use them in places that are exposed to sunlight or high heat, cut the end off properly an they will last just as long as the wax string.
 
The white nylon zips that Spruce sells are higher quality than you’ll get at auto parts places. I keep several sizes on the shelf next to the Grip Lock Ties and use them regularly. I also have some stainless steel ties but haven’t ever used one. I don’t even remember why I bought them.
 
Where there is vibration there is ALWAYS relative motion. Motor mounts have been damaged by zip-ties. Grit gets under them and vibration can slowly saw into/through the thin metal tubing.
 
Lindberg said:
Faster than it saws through the plastic?
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It doesn't have to be faster; it just has to be "at all". Engine mounts are very spendy, and I'd hate to see one with several grooves in the tubing, just waiting to redirect stress.
 
LesGawlik said:
All the complaints are eliminated. They will not cut through structures.
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FYI: any releasable tywrap can in right conditions and load can self-release. Their lock tab can also be displaced accidentally during other tasks. So long as they're used in no-load locations like binding the harness vs holding harnesses I've not seen any major issues but have seen harnesses damaged from the self-release.
 
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kmacht said:
Zip ties being bad in an engine compartment is an old myth.
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They still can be depending on build quality. All the OEM ones you see on vehicles and any aircraft are all produced per a spec that exceeds most uses/locations. Some are even specifically made for engine compartments. The problem is at the low end like 1000 tywraps for $1. They have zero temp ratings and can fail at 100 degrees or in severe vibration environments. But its not the band that fails, its the lock tab becomes pliable or simply folds over because its so thin which in turn allows the tywrap to pop open. While not as common today, some of the mil-spec tywraps still use a metal lock tab.
 
There are a ton of zip ties on my experimental gyro. I found the ones at HD are mil spec and seem to do fine. Their black ones are more UV resistant, so I use those for exposed areas.
 
thito01 said:
I know this may be a stupid question, but are there specific zip-ties to be used in aircraft? Or, can we go down to the local big-box and get some to use?
Click to expand...

Most things aviation have a specification
MS3367
 
LesGawlik said:
Yes. All the complaints are eliminated. They will not cut through structures.

Rubber Lined, Releasable, Heavy-Duty Zip Ties, UV Rated, 8 Inch, Reusable, Black Nylon Zip Ties, Assorted Colors (Blue, Red, Orange) - GripLockTies (100, B
available at the 'Zon.
Click to expand...

Like an adel clamp had a kid with a zip tie.

I keep waiting for some chinesium knock-off of those things to appear so I can try them out. I don't know why a 50 cent zip tie annoys me, but it does.
 
Kenny Phillips said:
It doesn't have to be faster; it just has to be "at all". Engine mounts are very spendy, and I'd hate to see one with several grooves in the tubing, just waiting to redirect stress.
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Why can't grit get under the rubber ones?
 
Domenick said:
Where there is vibration there is ALWAYS relative motion. Motor mounts have been damaged by zip-ties. Grit gets under them and vibration can slowly saw into/through the thin metal tubing.
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Please share pics of motor mounts damaged by zip ties. I have heard that rumor every time the topic comes up but still have not seen one engine mount that had its metal damaged by a simple zip tie. Take some regular sandpaper and let me know how long it takes you to sand through some 4130 by hand
 
kmacht said:
Please share pics of motor mounts damaged by zip ties. I have heard that rumor every time the topic comes up but still have not seen one engine mount that had its metal damaged by a simple zip tie.
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Never took any pictures but have seen the results a number of times on 4130 mounts and stainless steel hyd lines. However your sandpaper example is not accurate. Now take some course lapping compound and vibrate it on an area similar to the tywrap under load and if I had to guess it takes about 8-10 months to cut through the .050" tube wall. Its not the grit under the tywrap that does the damage as it is the oil that mixes with it. The weird thing is the tywrap wont move until its too late.
 
Hmmm, we have Nuclear Grade cable ties at work. Maybe they'll do?

Actually, I think they're just OSHA compliant for the pull test. Pretty blue though.
 
kmacht said:
Please share pics of motor mounts damaged by zip ties. I have heard that rumor every time the topic comes up but still have not seen one engine mount that had its metal damaged by a simple zip tie. Take some regular sandpaper and let me know how long it takes you to sand through some 4130 by hand
Click to expand...

I've seen it. It happens. Not gonna argue otherwise.
 
kyleb said:
I've seen it. It happens. Not gonna argue otherwise.
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Same reply I always see when asked. I saw it or “it happened to a friend” yet nobody is ever able to produce any proof. If zip ties were so bad you would think there would be hundreds of examples floating around on the web.
 
My AnP uses zip ties to the motor mount, but uses a small piece of old tire tube wrapped around the mount under the zip tie. No fuss, no muss, no sawing action.
 
Domenick said:
Motor mounts have been damaged by zip-ties. Grit gets under them and vibration can slowly saw into/through the thin metal tubing.
Click to expand...
So don't use 'em on your motor mount. When used appropriately (Per AC43.13-1b) they are functional and acceptable, to the point where my new ignition harness provided by Lycoming included several in the installation bag.

Nauga,
fit to be tied
 
When my exp Cub was inspected by my DAR he took exception to some of my zip ties at the engine mount. He told me to cut them off and re-do them using a second zip tie as a choker to make the wire bundles stand off the tube. No problems. No sign of any wear on the powder coated engine mount. Not as much as a scuff.
 
I'm envious that some of you guys are flying enough that 1) Zip ties get a little loose, 2) grit gets underneath them, 3) oil mixes with the grit, 4) and vibration continues long enough to cause a compromise in the surface on which the zip tie is mounted. It seems like that process should proceed at about the same pace as stalactite formation. That happens, too. I've seen the results.
 
I have encountered zip-tie-damaged engine mounts way too many times. I've had to take a couple off and send them in to have sections of tubing replaced. That tubing typically has a .035" wall thickness; the allowable wear on it is 10% of the thickness, so any damage deeper than about the thickness of a sheet of printer paper (.003") is beyond the spec.

Grit---sand, dust, whatever---gets under that tie and embeds in it. A sheet of sandpaper has grit glued to a sheet of paper; what suffers the most when you use it on metal? The metal does. Not the paper.

In the 1970s for a time I was a partsman in a shop that sold heavy-duty brake stuff for big trucks and earthmovers. At the time the whole industry was shifting from copper air brake tubing to the new reinforced nylon tubing. Easy to cut with a knife, easy to bend around stuff without it kinking. Didn't dent or break easily. Didn't corrode. Didn't work-harden and crack. But one day a trucker came in and took me out to see the frame on his truck, where a section of 1/2" nylon tubing had been rubbing on the top flange of the frame rail. Logging truck in the dust and sand all the time. That tubing had eaten more than 1/4" into that thick frame rail and the tubing itself was relatively undamaged. Pretty stark. No oil needed, either. Just dirt and a section of nylon and some vibration.

Those that don't believe it are welcome to disbelieve it, but when their mechanic someday says that their engine mount must be rebuilt, they'll join the crowd of others that also learned it the hard way.

Adel clamps, rubber-lined, clamp firmly to the tubing and do not shift. The grit can't get under them because of the tight interface. An annual inspection should be checking all that stuff, since heat and oil take their toll on them, and when they get loose or the rubber starts failing, they should be replaced. They're a lot cheaper than engine mounts.

Don't buy zip-ties at the local hardware store. They are not all created equal. I've had the cheap ones get real brittle in cooler weather, impossible to install without them snapping.

Here's an excerpt from an article written by a guy who had a mount repaired, and then talked to the shop owner. He quotes the owner:

While at the Loree shop, I also saw tubes that were dented during installation and removal by sloppy tool handling; and tubes that had been scratched or scored by abrasion.

Since these tubes are so thin, what may at first appear to be negligible damage usually needs attention. “Our standard for repair is 10 percent of the tube thickness,” said Loree.

One thing Loree was adamant about is avoiding the use of plastic tie-wraps (i.e., zip ties) to secure anything to a welded steel mount. He has seen it again and again: plastic tie-wraps will wear a welded steel mount tube faster than a pilot heads to a restroom after a cross-country flight. It takes longer to install properly-sized Adel clamps, but they are the only clamping device Loree wants used on an engine mount.

From https://www.cessnaflyer.org/maintenance-tech/item/1146-engine-mounts-explained.html
 
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