Teflon wire question

[IowaRV9Dreamer]

I bought a couple small rolls of teflon wire M16878/4B. Some web seraching reveals that this is an older mil spec, but is a teflon wire. The only real difference I see is that it has 7 strands instead of 19 (in the M22759/16 Tefzel wire Stein sells).

Does anyone know if the 7 strand wire will work? I'm wondering about crimp connections, in Faston or D connector contacts.

If anyone is interested, here is an intersting teflon wire link:
http://www.logwell.com/tech/shdwe/teflon_wire.html

[Mike S]

I cant think of a reason it would not work, but then, I think the best thing you could do is to contact Stein, or someone else in the business, and ask them.

As far as I know, the big advantage of higher strand count is flexibility.

[az_gila]

The specification for the wire you have is here -

http://www.everyspec.com/MIL-SPECS/M...-4C.005789.PDF

There should be a couple of more letters after the /4 to fully identify the wire.

The above spec. has a replacement table on page 4 giving the later specs. for similar wire. Some variants are equivalent to MIL-W-22579/11 or /22 wire depending on the exact part number of what you have.

Ther newer specs are listed in AC 43.13-1B as OK for "protected wiring" whereas MIL-W-22579/16 is listed for "open wiring". Check section 11.77 of the AC.

The specific application on your RV will really determine if it is OK...

PS the wire you have may be to an obsolete Mil spec. but it appears it is still being made -

http://www.jchwire.com/jchwire/catalog/HookUp183.htm

[IowaRV9Dreamer]

Thanks Gil - I like the specs website a lot...

This wire is M16878/4BGB1, which is a silver plated copper 20AWG wire.

I'll check out the AC... if there is any question I'll end up buying new wire.

dave

[SteinAir]

There are a couple reasons not to use it. #1 is the fact that it's silver plated; which one would initially assume is better than tin, but in aircraft that is not necessarily so. The silver plating makes the wire quite brittle in comparison to tin plating and will not resist bents/vibration/etc.. very well because it's very stiff. #2 is the pure teflon coating. Not as bad as the silver plating, but if you clamp it or zip tie it tightly, the teflon will over time just cold flow around the fastening device. #3 is the fact that Teflon is so slippery it makes it a pain to work with as far as stripping, etc.. With Teflon you almost have to use the copression dies to do a good job.

Anyway, that's a short/quick version of the negatives. In the right instances it could be used, but overall I'd just avoid it. It's a very common suprlus wire....

My 2 cents as usual.

Cheers,
Stein

[fl-mike]

We use lots of 16878 for internal hook-up wire in our boxes here at work. The same "pinch" stripper dies are used for it and 22759. Tefzel (22759) is preferred for airframe wiring because it is less prone to cold-flow than straight Teflon. I went with 22759 on my plane.

[az_gila]

Originally Posted by fl-mike

We use lots of 16878 for internal hook-up wire in our boxes here at work. .....

Which is basically the "Protected Wiring" mentioned in AC 43.13

[Bevan]

I have bought wire from several sources over the past couple years. Some do not have any spec stamped along the wire that I can see (maybe I need a magnifying glass). All of it was bought through reputable online sources for aircraft use such as Van's, Steinair, B&C etc. How can I identify this wire? Should unstamped wire be avoided altogether?

Bevan
RV7A wiring

[fl-mike]

Originally Posted by az_gila

Which is basically the "Protected Wiring" mentioned in AC 43.13

Exactly. .

[SteinAir]

If it's mil-spec wire it should be inked every "x" number of inches with the spec. Often times it can be hard to read the imprints on colored wire, but I've yet to see a spool where it didn't exist at all. Since wire is no longer allowed to be stamped, it's usually lasered or inkjetted which means the lettering can possibly wear a bit, or is just plain darned hard to read. It may be difficult to find the writing in some short chunks, but in longer chunks you should be able to find it somewhere. We usually look over the spools when they arrive, but like I said we haven't found one yet that is totally missing a stamp. Ocassionally their labeline machine may miss a couple fee, but that is actually within spec. If it's lasered on dark colored wires it's near impossible to read unless it was coated to chemically show the etching. Green's, Browns, etc.. are all hard to see. White wire is usually pretty easy.

Hope that helps!

Cheers,
Stein