Exterior wiring through foam composite

[headingwest]

Hi all,

Any ideas for wiring exterior items (eg lights) through foam composite panels?
Are there long waterproof grommets? Something to stop the wires rubbing? Also if I fill with silicon how do I replace faulty parts when the wires run through the shell?

Thanks for any ideas,

Jim.

 

[pugslyyy]

I wouldn't be super worried about vertical pass-throughs (i.e. walls), but for the roof (solar, antennas, etc) it makes sense to have as few holes as possible. I like to have a single hole with feeding multiple devices. As with a lot of things for overland, the marine industry is your friend for this.

Cable Clams - Blue Sea Systems

Engineering high quality marine electrical components for safety, reliability and performance

www.bluesea.com

 

[Alloy]

I wouldn't be super worried about vertical pass-throughs (i.e. walls), but for the roof (solar, antennas, etc) it makes sense to have as few holes as possible. I like to have a single hole with feeding multiple devices. As with a lot of things for overland, the marine industry is your friend for this.

Cable Clams - Blue Sea Systems

Engineering high quality marine electrical components for safety, reliability and performance

www.bluesea.com

Cable claims are great. I like to use them for multiple cables that may require the wires to be changed.

Edit....where the backside is no accessible the cable clam bolts will need to be drilled an tapped.

For single wires and cable like SOOW and 12VDC duplex I use a strain relief.

Shopping

www.factorymation.com

These come in straight and tappeerd ( NPT / pipe) thread. I like to use the tapered thread. One needs the right size (NPT) tap and I use a hole saw as twist drills tend to splinter the fiberglass. The threads and wire are sealed with black urethane.

Wires penetrating vertical walls need a drip loop.

https://www.efficientplantmag.com/wp-content/uploads/images/stories/2013/0913fund4.jpg

If the wire isn't jacketed where it passes through the inside of the panel/wall I will drill a bigger hole to provide more clearance or wrap the wire to protect it from abrasion.

 

[Joe917]

use something like this:

Do not use silicone EVER on the exterior of your vehicle!

 

[luthj]

A single bonded down pass through box for the roof is best.

 

[jwiereng]

Why not use silicone?

 

[luthj]

Nothing will bond to cured silicone, not even more silicone. So if you ever need to repair or change something, you are in trouble. If a non-neutral cure silicone is used, it can also cause corrosion issues on some metal surfaces.

 

[Joe917]

silicone fails. when it fails nothing will bond to it including new silicone.... luthj beat me to it!
Cured silicone must be removed completely, mechanically and then chemically before a new bond. Trust me don't go there.