What's new
Van's Air Force

The definitive Van's Aircraft support community! Buying, building or flying an RV? Join our exclusive family of mentors and enthusiasts!

Spiral Wrap

D

David Paule

Well Known Member
Ambassador
Spiral wrap is a very effective and convenient thing for keeping hoses and wires from chafing. But the standard, readily available kind is nylon or polyethylene and in a warm engine compartment, it can melt and drip. It’s happened to me. It’s rated for up to 190 F and comes in colors.

The interesting thing is that after being heat-affected like that, it doesn’t seem to be bothered by high temperatures. Unfortunately it becomes, not brittle, but not flexible and limber either. It still works for preventing chafing, but doesn’t let hoses or wires flex much. It's practically impossible to unwind it.

If you then have an A&P or AI see it, the inspector might make you remove it. It happened to me.

For my RV-3B project, I spent the big bucks and bought the PTFE version. It’s good for up to 500 F and it’s chemical resistant. It comes in black or semi-clear white at around ten times the cost.

The part number for what I have on order at McMaster is 7432K112. Ten feet of the black cost me $46.58 including tax and shipping (October 2025). I chose black because the semi-clear white wasn’t available in 10’ lengths, and the cost for a 25’ length would have been much higher. Besides, I only need a foot or two.

Dave
 
Wow. Thats steep. I have had this happen but only where it touched the exhaust due to improper installation.
It’s still there, all hard and curled up, but not touching. At least it doesn’t appear to be flammable or combustible.
 
I've received the PTFE spiral wrap, pricey stuff, and it turns out that it does not work well above about 5/15" expanded ID. It's supposed to expend up to 1" and it doesn't seem to actually be effective much larger than I mentioned. It's slick, of course, and tends to not stay on larger diameter things. Of course the higher the friction the better for the underlying hose or whatever.

I'll post follow-ups as this evolves. I might get some of McMaster's "High Strength Spiral Sleeving," good up to 280 F and considerably cheaper.

Dave
 
I have to admit that I have never liked the spiral wrap - when used FWF, oil and dirt get inside, it ages terribly from heat, etc, etc…. Simply lacing wiring bundles makes a pretty engine compartment, but you also get dirt and oil contamination in the bundles after time. Traditional “Snakeskin” is great - but you have to feed all the wires in from the end, so it requires significant planning. When I was disassembling the Zero motorcycle to strip it for powering our eXenos, I ran across something that looks as good as snakeskin but is split - it sort of wraps itself around the bundle in a double layer, so you can install it on finished bundles, without having access to the e of the bundles. I have used it in engine compartments and it stands up very well (no degradation noticeable) to the temps experienced inside or outside the baffles. Here’s a link to start your search….

Alex Tech 25ft - 1/2 inch Cord Protector Wire Loom Tubing Cable Sleeve Split Sleeving For USB Cable Power Cord Audio Video Cable – Protect Cat From Chewing Cords - Black https://a.co/d/iJhWI0z
 
Probably similar to what Paul mentioned, Airbus uses Roundit 2000 style Nomex self closing sleeving all over the place now. You can get chunks on eBay. Wires can enter and exit along the length.
EBay seller
 
Last edited:
You must log in or register to reply here.
Back
Top