What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Sizing the eyeball firewall pass throughs?

If you haven’t installed them yet it’s probably worth reading through some of the VAF pros and cons. I used the aluminum ball type sold by Vans for the push pull cables. They look to be the same as the ACS product. They come in a vast array of hole sizes and fit well to the cables. I found them extremely fussy to install as you can see from nilberg’s post. The aluminum version is not the best for fire protection.

https://vansairforce.net/community/showthread.php?t=179490&page=2

This is the company that manufactured the ones I have:
https://www.firewallfittings.com/
 
Eyeballs are an expensive, fussy PITA.

Drill a 1/2 hole and four 1/8" holes, install four SS pop rivets, install the cable and pump sealant into the annular space. Done.

Tubular penetrations are gas tight and entirely fireproof, which can't be said for eyeballs. An intumescent sealant swells to keep the annular space closed as the plastic insulation or sheath melts away. Here's one heated red hot, with a section of #6 wire. The intumescent sealant is squeezing out the back, still fully sealed.

BTW, this is standard fire code for firewall penetrations in commercial buildings.
.
 

Attachments

  • ScreenHunter_1791 Jun. 21 12.49.jpg
    ScreenHunter_1791 Jun. 21 12.49.jpg
    27 KB · Views: 360
Eyeballs

claycookiemonster said:
These:

https://www.aircraftspruce.com/catalog/appages/eyeballfw2.php?clickkey=183193

Does this fitting split open so I size it for the portion of the cable which will rest inside once installed, or must the opening admit the largest portion of the cable?

If I must allow the largest portion of the cable to pass through, what is the best way to seal around the smaller diameter portion once it's installed?
Click to expand...

I used the eyeballs for the three big cables. I still have the part numbers if you need. Pick the hole diameter that matches the outside cable diameter. Yes, pain to install but I liked the ability to point the cable. Once tightened, it's not moving. I used the home brew steel AN fitting for the smaller Bowden cables. They bend much easier.
YMMV
 
Why is this hard?

I've made the AN fitting firewall pass thru for the simpler Heat, and Oil Temp shutter and Alt Air. For some reason, ACS can't decode my questions regarding the size to order for the SS eyeball fittings. I just needed to know whether to size it for the cable or the fittings on each end of the cable. The cable is 5/16" and the ends with the nuts and fittings are 7/16". It sounds like I need to size the eyeballs for the cable since the fitting splits open and can be reassembled AROUND the cable, rather than passing the cable through it?

I think I have it now. Maybe. Hopefully. 99 3/4 % guaranteed.
 
Dan ....what sealant do you recommend?

DanH said:
Eyeballs are an expensive, fussy PITA.

Drill a 1/2 hole and four 1/8" holes, install four SS pop rivets, install the cable and pump sealant into the annular space. Done.

Tubular penetrations are gas tight and entirely fireproof, which can't be said for eyeballs. An intumescent sealant swells to keep the annular space closed as the plastic insulation or sheath melts away. Here's one heated red hot, with a section of #6 wire. The intumescent sealant is squeezing out the back, still fully sealed.

BTW, this is standard fire code for firewall penetrations in commercial buildings.
.
Click to expand...

HEH DAN ....what sealant would you recommend? What is the one used in the pictures ? Many thanks. Stew
 
claycookiemonster said:
I've made the AN fitting firewall pass thru for the simpler Heat, and Oil Temp shutter and Alt Air. For some reason, ACS can't decode my questions regarding the size to order for the SS eyeball fittings. I just needed to know whether to size it for the cable or the fittings on each end of the cable. The cable is 5/16" and the ends with the nuts and fittings are 7/16". It sounds like I need to size the eyeballs for the cable since the fitting splits open and can be reassembled AROUND the cable, rather than passing the cable through it?

I think I have it now. Maybe. Hopefully. 99 3/4 % guaranteed.
Click to expand...

Call Doubletree Products. (Link posted in a previous post) They are extremely helpful and you can buy from them.
 
Simple is Good

DanH said:
Eyeballs are an expensive, fussy PITA.

Drill a 1/2 hole and four 1/8" holes, install four SS pop rivets, install the cable and pump sealant into the annular space. Done.
Click to expand...

Dan,

Is this your solution for all penetrations, or just wire passthru?

Thanks,
Mike
 
You must log in or register to reply here.
Back
Top