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Tie-Wrap Temperature Ratings

WingedFrog

WingedFrog

Well Known Member
In section 46 VANs instructions direct to tie-wrap electric wires to parts of the engine that can get pretty hot, among them coolant hoses. I used the tie-wraps provided and packaged by VANs. As I was concerned to be short, I checked a tie-wrap package I bought at Harbor Freight. They are made of Dupont 66 nylon and are rated up to 185 deg Fahrenheit. Per Rotax the coolant can go up to 248 deg Fahrenheit. Obviously such tie-wraps are not appropriate but as VANs tie-wraps come without markings I have no way to know for what temp they are rated. Short of asking VANs (it's Sunday!), I am wondering if anyone in this Forum has addressed this issue?
 
Tie Wraps

Boy, it was about a year ago with many tie wraps forward of the firewall, all for good cause. The FAA inspector arrived for that special day when I was to be issued my certification. It didn't happen! With few exceptions, all tie wraps had to be replaced with Adel clamps to hold the various wires in place.
My 2 cents worth.

Jim Diehl N891DD
7A
 
NASA515 said:
I asked the same question - I bought high temp Tefzel zip-ties. They were a little pricy. - they're blue and I only use them FW Forward. I thought I bought them from Aircraft Spruce but can't find them now - here are some at SteinAir:

http://www.steinair.com/storedetail.cfm?productid=69

Bob Bogash
N737G
Click to expand...

I did not know high temp zip-ties existed. As they are color coded, this tells me that VANs supplies are probably not adequate. This seems confirmed by what Jim said above. I think this issue needs to be addressed at VANs and I will call them tomorrow but Scott's input would be also useful here.
 
jdiehl said:
Boy, it was about a year ago with many tie wraps forward of the firewall, all for good cause. The FAA inspector arrived for that special day when I was to be issued my certification. It didn't happen! With few exceptions, all tie wraps had to be replaced with Adel clamps to hold the various wires in place.
My 2 cents worth.

Jim Diehl N891DD
7A
Click to expand...

So Jim, to satisfy the FAA inspector you had to violate the E-LSA rule? :eek:
 
tie wraps

I didn't mean to stir the pot--and I'm certainly not familiar with E-LSA rules. But, to get the FAA signoff on my 7A project, I had to tear out all of the tie wraps in which guidance was provided by several A&P's. At least at my FSDO they didn't want to see anything securing wires other than adel clamps. When I read the post, it brought back the cold chill of when I was told that they (ties)had to go.

Jim
 
Interestingly, the Rotax comes with wide black tie wraps installed in several locations. I don't know what type they are, but I assume they must be OK.

However when my tech counsellor came to have a look at my build recently, he wasn't altogether happy with the white Vans tie wraps that I had installed in some places. He didn't say not to use them but he recommended replacing them with Adel clamps.
 
jdiehl said:
I didn't mean to stir the pot--and I'm certainly not familiar with E-LSA rules. But, to get the FAA signoff on my 7A project, I had to tear out all of the tie wraps in which guidance was provided by several A&P's. At least at my FSDO they didn't want to see anything securing wires other than adel clamps. When I read the post, it brought back the cold chill of when I was told that they (ties)had to go.

Jim
Click to expand...

OMG! I have 100 lbs in my airplane. And another 100 lbs of Spirap.

And I thought I was doin' good.....

Bob Bogash
N737G
 
jdiehl said:
I didn't mean to stir the pot--and I'm certainly not familiar with E-LSA rules. But, to get the FAA signoff on my 7A project, I had to tear out all of the tie wraps in which guidance was provided by several A&P's. At least at my FSDO they didn't want to see anything securing wires other than adel clamps. When I read the post, it brought back the cold chill of when I was told that they (ties)had to go.

Jim
Click to expand...

If you walk the displays at Oshkosh or other trade shows, you'll see tie-wraps under the cowling of a number of brand new productin aircraft.

The glass transition temperature of Nylon 6,6 is 50C or about 122F, which means the material will start stretching or deforming under load at that temperature. But we don't put them under load - all we do is strap a few light wires to something else, so the Tg doesn't really matter.

Bottom line is that tie wraps are not a bad thing. There may be better solutions, but don't let people (even the FAA) convince you that tie wraps are categorically bad...
 
Well, I guess this once again proves that there are lots of differing opinions, even within the FAA. My FSDO guy raised no issues at all about my white tie-wraps. I know he looked at them because he told me I wasn't clipping the tails off close enough so as to prevent cutting my hands on them. Matter of fact he told me where I could get a better pair of clippers!;)
 
One thing to consider with tie wraps: if secured to the engine mount, be sure to provide some sort of abrasion prevention to protect the motor mount. Grit can work its way under the wrap and start sawing on the motor mount and the tie wrap's sharp edges can do the same.

I too had some folks raise their eyebrows with using tie wraps but it was offset with the abrasion prevention.
 
Just a small addition to Kyle's (right on and adequate in it's own right) explanation.

The RV-12 E-LSA kit is based on an RV-12 that the FAA inspected and approved to meet S-LSA certification requirements. This inspection was done by four FAA officials.

The Engine installation is pretty much the same now as it was for that inspection.

It is not practical for every single little aspect of a design to be tested in detail (like measuring what surface temp. a coolant hose develops during hot weather operations).
Sometimes it is simpler to rely on longevity testing (in instances where it is not a flight critical issue). That is what was done in this instance. If evidence acquired during testing indicated that high temp tie wraps were needed, they would have been issued in the kit.

By the time the FAA inspected N412RV for compliance as an S-LSA, it had many many hundreds of hours, with the same tie wraps, in the same locations, with no evidence of degradation.
 
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