Replies to This Discussion

Permalink Reply by Loren Warner on June 12, 2017 at 4:43pm

For our build, all firewall forward wires are in a nylon loom.  We then use nylon ties to secure most everything.  We use Adel clamp or similar if there's a possibility of falling onto exhaust or rotating part.  

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Permalink Reply by david shrader on June 12, 2017 at 5:07pm

I've literally seen hundreds of zip ties cut into steel tubing. Avoid it all costs. Use rubber hose or fire sleeve around the tubing then zip tie it off. I have done this for years and the engine mounts look good as new. Also look into string tie for your wire bundles if your looking for something more cost effective an durable, it takes a while to learn the knot but gives good results an won't cut ur hands like zip ties.

Zip ties are fine around wire bundles the point is to not use them when standing off around a steel tube like your engine mount.

Dave

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Permalink Reply by Jon Croke on June 12, 2017 at 8:48pm

Very end of HomebuiltHELP Tip #39 video http://homebuilthelp.com/Tip_of_Week/tip_archive.html shows an alternative method for ties using silicone tape.

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Permalink Reply by Paul Sanders on June 13, 2017 at 10:42am

Ooh, how is it I've never heard of this tape, it looks amazing. 

Given the heat resistance, could it be used at an insulating tape? Some of the areas where the coolant hose is a little close to the exhaust, perhaps? Wrap it around there a few times, or would that prevent cooling?

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Permalink Reply by John Austin on June 13, 2017 at 4:30pm

I think Thermotec sleeving would work even better if you're primarily trying to protect a hose from radiant heat.  You can get it slit down one side with Velcro closure so that you can install it without having to disconnect the hose.

Here's some on a fuel line:

I used zip ties to ensure the Velcro would stay closed - nylon ties in this case since this is not exposed to very high temps and are not critical - the Velcro holds very well!  I'm going to keep an eye on them for premature deterioration and replace them with stainless ties if necessary.  I'd definitely use stainless if near the exhaust!

John

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Permalink Reply by Paul Sanders on June 14, 2017 at 9:59am

Thanks John, I'll check that out. I was going to use some firesleeve (steel) zip tied around the bottom of the hose but it is so thick, it pretty much touches the exhaust where it is the hottest. That is possible ok, I don't know, but I like the velcro idea here.

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Permalink Reply by Christopher Nail on June 13, 2017 at 5:07am

Adel clamp around engine mount attached to wiring bound adel clamp.

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Permalink Reply by John Austin on June 13, 2017 at 6:19am

I take a practical approach to the use of tie wraps firewall-forward - if the area is relatively "cool," such as on the firewall itself, I use nylon tie wraps.  The closer I get to the engine, exhaust, or rotating parts, I use more Adel clamps.  I use stainless steel tie wraps to secure exhaust wrap. My DAR had no problems with this approach.

Most of my firewall-forward wiring is protected by either corrugated plastic wire loom or "snake skin" wire loom.  I protect engine mount tubing with silicone "Rescue Tape" if I'm securing a tie wrap to it - in nearly 5 years and 470+ hours, I've never seen even the tiniest bit of abrasion of the silicone tape, much less abrasion of the steel tubing underneath.  Like Loren, I use Adel clamps when securing wiring or tubing near hot exhaust or rotating parts where failure is not an option!  

Tie wraps come in many different strengths and ratings for temperature.  I use Tefzel tie wraps directly on my cylinder head fins to secure CHT probe wires - their normal working range is rated to 338F.  I've never had one of these tie wraps fail, but even if they did, the unsecured probe wire wouldn't cause any damage.

John

N750A

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Permalink Reply by Paul Sanders on June 13, 2017 at 11:10am

Without wanting to drift my own thread, I'm curious about the exhaust wrap. I've read a lot of places that say don't ever use it as it destroys the exhaust but if you have 470+ hours maybe it doesn't. I would like something that stops my rad hoses from getting too hot, really not much room between them and the exhaust with the 912 ULS.

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Permalink Reply by John Austin on June 13, 2017 at 4:39pm

It depends on the materials and conditions involved as to whether exhaust wrap is a good idea or not!  Wrap non-stainless steel or cast iron headers with wrap and get it wet frequently (as in exposure to rain) and you'll get rust for sure!  However, stainless headers are relatively resistant to corrosion, especially if the wrap is kept dry.

I'm not using the exhaust wrap on my Jab's stainless headers - I'm using it on my stainless muffler and aluminum/stainless cabin heat muff.  I just installed it the other day, so I don't have 470+ hours on it!  However, I'm very comfortable in this application because the underlying metals are relatively corrosion-resistant and not exposed to rain (I don't fly in rain and the airplane is always hangared!).  I used exhaust wrap to cut down on the radiant heat to my fuel line and carb and also to retain the muffler's heat and cabin heat muff's heat to boost the efficiency of the cabin heat.

Again, I think Thermotec radiant heat barrier would be the way to go to protect a hose near an exhaust.

John

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Permalink Reply by Paul Sanders on June 15, 2017 at 10:07am

Thanks everyone! I'm getting some of that silicone tape for securing my wires and going to try out that Thermo-tec wrap for my radiator hose where it is close to the exhaust. 

So glad I found this all out before I had my inspection!

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