Firewall forward help (need photo's and advise)

[pfhoeycfi]

I am putting together a list of firewall "stuff" for ordering and was wondering if builders are using 1 or 2 firewall pass thru ducts for the wiring... ie is it better to run the high current conductors thru their own pass thru or will one common pass thru suffice? From the pictures I've seen on here and some of the build logs it appears that a single pass thru for wiring is common.

peter

[racaldwell]

Peter,

I am using two pass throughs for electrical, lot is to do with location. Battery & B Lead on lower right and engine sensor wiring upper left. There may be a picture on my EAA project page you could look at.

Rick Caldwell
Xenos 0057

[WesRagle]

Hi Peter,

I used two pass thrus as well. One for power, p-lead, master, starter, ... The other for signal wires. The firewall was penetrated in convenient locations such that the bundles could be routed/secured with cushion clamps bolted on along with the tank straps.

No good pics but ...
You can kinda see the signal bundle pass through in the corrugated/split sheath in this pic.


Power was routed through on the other side.

Wes

[NWade]

I am using 2 pass-throughs: One for electrical and one for my throttle & mixture controls. All of my power wires are protected with a fuse or a circuit breaker, so as long as there's not chafing I am not concerned about separating the wires into multiple passthroughs. Each additional passthrough is not only a potential for cockpit flames and smoke in the event of a fire, but its also a pathway for carbon monoxide, a place where riveted attachments/sleeves can fail, etc - so I'd rather have the fewest number of them possible.

With the electrical pass-through (and indeed all electrical wires) I'm using aircraft-grade Tefzel wiring of the appropriate gauge for the current and wire-length. To help prevent chafing against each other the wires are secured with a combination of self-fusing silicone tape and zip-ties. Where they pass through the firewall I am using an Aircraft Spruce kitthat has you wrap the wires in a firesleeve (to prevent wire-to-metal rubbing),and then an outer wrap of firesleeve with fire-caulk helps secure the whole assembly (wire bundles and stainless-steel pass-through) into a semi-sealed unit.


Here are a few pictures...

Stainless-steel pass-throughs are at the lower-right of this image: https://1drv.ms/u/s!ApMKXiyfUEPR0X6vbcPaLKmih4tl
Wiring and inner firesleeve in place, as viewed from the "cold" side of the firewall: https://1drv.ms/u/s!ApMKXiyfUEPRg7IIB3UNi4RtyiKILg
Outer firesleeve and caulking on the "hot" side of the firewall: https://1drv.ms/u/s!ApMKXiyfUEPRg7IGKnRw5XcmodJUKA

Hope this helps!

--Noel
Sonex #1339

[pfhoeycfi]

Thanks all! Perfect....

peter