eyeballs vs. bushings?

szicree · #1 08-31-2007, 09:05 PM

I see that the FWF instructions say to use a bushing in a bushing for the cables, but I've seen a lot of guys use the eyeballs. On the one hand, I suspect that an aluminum eyeball would survive fire (for a little while) and the bushing would disappear immediately. However, the bushing would be a much smaller hole. All opinions are very welcome.

dan · #2 08-31-2007, 10:13 PM

I think you hit the nail on the head in terms of fire protection...especially if you "hershey's kiss" the back side with firestop sealant.

But for me, the ANGLE at which the cable needs to penetrate was the kicker...why I went with eyeballs.

Rick S. · #3 09-01-2007, 06:09 PM

Having just installed 5 eyeballs I can say they:

1) Look good
2) Allow easy angle adjustment
3) I think it will take a while to burn through them
4) Takes awhile to drill them up the correct size at 1/16th" at time

I'd use them again, I did some pre-planning for their location and used Harbor Freight's el cheapo sheet metal punches to make the holes, $19.00 for a 4 piece set.....lots cheaper than the Greenlees and they are still going strong after many holes for the wiring and control cables.

dan · #4 09-01-2007, 07:17 PM

Rick,

Is this the same HF el cheapo kit you used?
http://www.harborfreight.com/cpi/cta...emnumber=91201

cytoxin · #5 09-01-2007, 07:20 PM

Quote:

Originally Posted by dan

Rick,

Is this the same HF el cheapo kit you used?
http://www.harborfreight.com/cpi/cta...emnumber=91201

did these work..i was a little skeptical when i saw them at HF.

walter · #6 09-01-2007, 08:29 PM

At OSH this year I spent a good amount of time looking very carefully under the cowl of the Cirrus airplanes with the cowling removed. If you get the chance, it's well worth it. The eye-opener was that most of the wires coming through the firewall were completely covered, on the engine side, with about an inch plus thickness of high temperature RTV, nicely gobbed on in a circular pattern. It wasn't apparent what the underlying passthrough was, either eyeball or bushing. For a certified aircraft, I didn't expect that. Now, I'm just assuming it's the regular red High Temp RTV. It could be something else but it looks, smells and feels just like it. If it works for them on certified aircraft...

Rick S. · #7 09-02-2007, 12:35 PM

Dan & William

Those are the Harbor Freight punches I was refering to, they work like a champ. Main difference between those and the Greenlees was the tolerance between the dies. You have to go slow to make sure they are sliding into each other before cranking on them hard but for the sale price (I paid $19 for them about two months ago) well worth the investment. I use a little 1" scotchbrite wheel I found at Sear to polish up the holes. Once I used the wheel a few times it was small enough to use on little holes 1/2" and up. I have not been able to find them anyplace but Sears.

Finley Atherton · #8 09-02-2007, 03:11 PM

Steve,
I have never seen an eyeball fitting in the flesh so I can?t comment on them but I guess they would be the preferred option. However compared to the Vans bushing in a bushing method they are relatively expensive, and due to their size I imagine they could be more difficult to install. I used the Vans method and am happy with the result. I prosealed the bushes as Vans suggests, but then decided the proseal would not offer enough fire protection so I then covered the proseal with a liberal layer of Vans Firewall Sealant. Cheap, easy, lightweight, looks neat and I think reasonably fire resistant.
Fin 9A