Securing wiring

[N3UW]

I am a big fan of lace. The primary reason I like it is because there are no sharp ends to cut yourself or other wires. Also in some areas like the engine mount, wire ties can get grit under themselves and end up working like sand paper or a grinding wheel and cut through tube over time. Whenever I use wire ties over round tube, I put a piece of silicone rescue tape around the tube then use a wire tie. That solution would also work well with lace. As far as wire ties go the only ties I like are Thomas and Betts ty-raps with the metal tab. These are nylon and if they are not inside the engine compartment they will last for a long long time.

Thomas and Betts TR TY526MX Cable TIE 30LB 11" UV BL (Pack of 100) https://www.amazon.com/dp/B001DEHV36..._BSmTCbVZG9WJM

[Bcone1381]

No one has mentioned stand-offs. I used them installing my fuel line. I used a short piece of rubber tubing and a zip tie and think the combo is nifty. I also use rubber tubing as a bumper (second photo). I prefer things like fuel lines and wiring to be set off from structures. (I've ordered better zip ties due to this thread.) A small wire bundle might use a smaller, lighter tube for the stand off secured with the waxed nylon lacing cord. That stuff would also improve the security of my rubber bumper.

IMG_6936.JPGIMG_6938.JPG

[nborer]

I’ve seen the standoffs used for wiring to the Tanis heater probes in a high-vibration area like the engine in our club planes. I also think this is done to keep the wiring away from higher-temp engine components. One thing to consider for your fuel line... I seem to recall that zip ties can saw through soft aluminum with a little vibration and time. It may be worth wrapping that section of the line that is currently in contact with the zip tie with some rubber tubing. That said, I did a quick search and couldn’t re-find said advice, so I don’t recall if I actually read it or just made it up.

[svyolo]

Lace, in and of itself, is a very small surface area that can saw through something as well as anything, unless protected with something.. Modern lace is probably also synthetic. Nylon or polyester. Zip ties are also synthetic, at least most are. There are some really cheap, catastrophic ones that will break upon installation. If nylon lace is the best way, why is a good nylon zip tie prone to failure? Same material. If the really thin nylon lace lasts 30 years, why would a zip tie made out of the same stuff not last the same, or longer?

Question, not a statement.

I will be using lots of lace. Nothing against it.

[JimParker256]

The lacing cord I bought is waxed cotton — not synthetic. That said, I plan to use shrink-tube under the lacing if I use it on fuel lines.

[Bcone1381]

Whee (and maybe others) can't read comments, so I included them below in italics.

Nborer says
I’ve seen the standoffs used for wiring to the Tanis heater probes in a high-vibration area like the engine in our club planes. I also think this is done to keep the wiring away from higher-temp engine components. One thing to consider for your fuel line... I seem to recall that zip ties can saw through soft aluminum with a little vibration and time. It may be worth wrapping that section of the line that is currently in contact with the zip tie with some rubber tubing. That said, I did a quick search and couldn’t re-find said advice, so I don’t recall if I actually read it or just made it up.

Jim Parker says
The lacing cord I bought is waxed cotton — not synthetic. That said, I plan to use shrink-tube under the lacing if I use it on fuel lines.

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[Bcone1381]

Cable ties and aluminum fuel lines don't mix too well, huh? Is it a wives tail if a trusted colleague has not had an issue with it yet? Does a standard exist that we can trust regarding cable ties and there ability to saw thru fuel lines and steel engine mounts. I searched AC43.13 and I don't see much there.

I suppose vibration and dirt under the cable tie is a combo that might do some damage over a long period of time.

I did see a good article linked below on tying wiring with lacing cord. It also showed wiring connected to aluminum tubing, and the tubing is protected with self fusing silicon rubber tape. I'll be redoing my fuel line stand offs using a self fusing silicone tape for protection. I'd like to see photos of Zip Tie damage.
http://www.aeroelectric.com/articles...able_lace.html

[nborer]

Brooks - I'll freely admit that I couldn't find a source to back up my claim on the zip tie and the fuel line. I was wary of posting it, but something about the picture sparked a memory that zip ties and soft aluminum fuel lines could eventually cause a problem. For all I know it was a dream or a wive's tale... I was hoping by posting that someone could either verify or debunk it.

svyolo - I'll take a stab at your question ("If the really thin nylon lace lasts 30 years, why would a zip tie made out of the same stuff not last the same, or longer?"). Just thinking through it, I think the difference between lace and ties could be that the lace is braided and/or stranded, and the zip tie is more or less homogeneous. Any small crack in the nylon zip tie will cause a stress concentration near the crack that will eventually lead to a failure. In a braided/stranded setup, a crack/imperfection/nick in one strand may cause a single strand to break, which will then increase the stresses on the remaining strands. However, the increase in stress in the strands will be uniform (or perhaps "more distributed," depending on the loading condition). That means that the next strands will fail sooner if another crack/imperfection/nick forms in that strand, but that would require another event (I realize "event" isn't entirely true) to create the initial damage. In an extreme example, note that aircraft use stranded rather than solid electrical wiring due to fatigue issues, as I understand it. But, even worse than my fuel line comment above, my zip tie vs. lace response is pure speculation (and not even an "I think I remember this..." moment). It could be that the vibrations are low enough, the zip tie design margins are high enough, or the consequences of zip tie deterioration over the life of an airplane is not an issue.

In terms of practical experience, I'm "plane captain" for one of our flying club airplanes, a C172. We recently had the engine overhauled, and there are zip ties all over it (both when it went out and when it came back). We had a Tanis heater installed, and I saw that the overhaul shop had installed zip ties to the heater wires with the standoffs that Brooks showed in his pictures - I even had to replace one recently because we had to replace one of the Tanis connectors (I cut the zip tie to be able to replace the wire - this wasn't due to a zip tie failure). Even though this is one of the highest vibration areas of the airplane, these are in a pretty visible, accessible area for routine maintenance, and most (if not all) of those zip ties will be replaced at the next overhaul, if not before. It makes perfect sense that zip ties were used, and we don't see it as any sort of safety issue.

[Bcone1381]

I appreciate you pointing out your concern.

[Glenn Patterson]

Our mechanic advised against using zip ties as much as possible. We used them to bundle the plug wires together to give them mutual support & stop them flopping around. He saw that & said that the zip ties would harm the wires. He showed us how to tie plug wires and hoses up with Koroseal cord that is a rubber like cord. I used double sided velcro where wires run along tubes. The soft side got a wrap around or a fold over a wire(s) and then a good firm wrap around the tube back over the velcro. My son is an electrician and was telling me about using a dbl sided velcro for electrical work on a job. Thats where I got the notion to try velcro. I used it to temporarily secure wires & could open the velcro to make changes. More were added to shorten the distance to about 6 " between ties and left it as permanent wire ties. Velcro was used to secure to secure pitot & static lines under the I panel to the Dynon. Basically everywhere that is accessible.

[spinningwrench]

Many radio shops will not use zip ties for securing wiring as it actually will cut into the insulation over time. Lacing cord is generally recommended.

[JimParker256]

There's an ongoing series in Kitplanes magazine where the author posts pictures of non-airworthy things he finds during both airworthiness certification inspections (he's a DAR) and annual condition inspections. One that stuck in my mind was a 1 or 2 year old airplane that had zip ties on the engine mounts. When he cut the zip ties, he found scoring on the engine mount, sufficient to require that the entire mount had to be replaced. So I won't be using zip ties to any tubing, and if I absolutely had to so so, I would use either the self-sealing rubber tape or shrink-wrap under the ties.

[Bcone1381]

Is there a secret on installing an easy standoff without using zip ties?

[Nev]

No one has mentioned stand-offs. I used them installing my fuel line. I used a short piece of rubber tubing and a zip tie and think the combo is nifty.

I like this idea. The new GripLock Ties might work well too. Any update on how it’s progressing?

[svyolo]

My update is the last 2.5 months I have seen a bunch of pictures of aircraft engine compartments. I wasn't looking for them, but I did note most of them had zip ties all over the engine compartment. I am sure most of them have crashed by now.

Just off the top of my head, at least one was a very late model Bonanza, a modern Cessna, and a certified turboprop, but I can't remember the type. Yesterday I saw a video of a guy picking up an older Bonanza with a brand new, upgraded engine he paid as an STC'ed upgrade. White zip ties everywhere. He probably paid something approaching 100k for that.

[Nev]

I’ve been noticing them a lot too now. Even in the work vehicle. I’m ordering a bunch of griplock ties.

[svyolo]

A mechanic found a zip tie that was wearing through a steel engine mount. Solution - ban zip ties. By the same logical thinking, magnetos fail every 300-700 hours. Shouldn't they be banned? Piston aircraft engines fail - I don't know - every 5-20,000 hours? Seems pretty risky to me. I won't even get into the number of mistakes made by human pilots.

There are a bunch of 60+ year old certified aircraft flying around in relative (?) safety. They are periodically inspected and maintained. Some by regulation, some by IRAN (Inspect and Replace as Necessary).

Zip ties might be the least of my concerns. I will be careful how and where I use them. But I will use them, unless the FAA bans them or AC43 says they are not suitable.

[Mark Goldberg]

For the engine compartment there are some "high temp" zip ties. Not a bad way to go where it is hot. Mark

[svyolo]

That is what I will be using.

[zkelley2]

A mechanic found a zip tie that was wearing through a steel engine mount. Solution - ban zip ties. By the same logical thinking, magnetos fail every 300-700 hours. Shouldn't they be banned? Piston aircraft engines fail - I don't know - every 5-20,000 hours? Seems pretty risky to me. I won't even get into the number of mistakes made by human pilots.

There are a bunch of 60+ year old certified aircraft flying around in relative (?) safety. They are periodically inspected and maintained. Some by regulation, some by IRAN (Inspect and Replace as Necessary).

Zip ties might be the least of my concerns. I will be careful how and where I use them. But I will use them, unless the FAA bans them or AC43 says they are not suitable.

The Griploc ties that I think the Patey brother's make have silicone on them to prevent this exact issue.

[Russellmn]

The Patey's are, as I understand it, the money behind the startup. Creighton King developed the product and started the company. Creighton is a member of the Flying Cowboys and another one that has a background in off road motorsports as well as flying.

[Bcone1381]

I like this idea. The new GripLock Ties might work well too. Any update on how it’s progressing?

I am vacuum bagging fiberglass as my method to fabricate gear leg fairings. This is my first time doing this sort of thing and was encouraged by a Jake and his wife, a recent visitor who bought a set of Patrol Plans after checking out my kit.

I removed the zip ties and replaced the attachment method with a waxed nylon string (50 lb tonsil strength) and some Kayak Building lashing knots I like called an Eskimo Knot. I believe the risk in standard tie wraps is that vibration allows abrasive dirt that may get between the steel and the wrap to wear on things. A wrap of silicone tape may protect against this. Silicone tie wraps too.....my sense is they are expensive specialty items. Prove me wrong.

After the gear leg fairings are done, I am moving on with the FWF.