Firewall Hole Plug

[jerry98b]

So, per plans I cut a hole in my firewall to pass the mixture cable through and ended up needing to cut it in a different location.

Any tips or best ways to cover or plug the old 1.25" hole in the firewall?

 

[skelrad]

For a hole that size, I'd just cut a square piece of stainless and rivet it over the hole (sealed with fire barrier).

 

[sf3543]

So, per plans I cut a hole in my firewall to pass the mixture cable through and ended up needing to cut it in a different location.

Any tips or best ways to cover or plug the old 1.25" hole in the firewall?View attachment 88672

I’d try to utilize it for something.
You could put in another pass through for wiring, maybe for an oil shutter cable, etc.
If not, I’d just use a nut and bolt and two fender washers to seal it. That way it’ll be there when you need it for something you forgot or decided to add.

 

[Mikeyb]

These spring plugs are great for stuff like that

 

[wirejock]

Yep. Choose a repair that allows use in the future. Stainless fender washers, bolt and nut is easy. Or get fancy and put a nutplate on one so the bolt can be installed from FWF side.

 

[RV7 To Go]

These spring plugs are great for stuff like thatView attachment 88677

What he said along with 3M Fire Barrier 2000 to seal it against fumes.

 

[Flyjon57]

So, per plans I cut a hole in my firewall to pass the mixture cable through and ended up needing to cut it in a different location.

Any tips or best ways to cover or plug the old 1.25" hole in the firewall?View attachment 88672

Jerry,
I think I have a spring plug in my parts box.
Jon

 

[Ron B.]

No skin in the game, but I wander if that spring plug would stay in place with a fire( one reason for a firewall) ? I would expect the firewall to warp with concentrated heat and could the plug pop out at the worst time?
Just asking.

 

[Flyjon57]

Jerry,
I think I have a spring plug in my parts box.
Jon

I don’t have a spring plug and will defer to sf3543’s suggestion of fender washers, bolt/nut, and fire sealant.

 

[jrs14855]

I don’t have a spring plug and will defer to sf3543’s suggestion of fender washers, bolt/nut, and fire sealant.

Use stainless fender washers and stainless hardware. I don't like the aluminum fittings at the other location. This has been posted many times but use a custom pass thru consisting of a stainless flange welded to a stainless tube around 2" long. 4 stainless machine screws at corners. Wrap cable with fire sleeve and inject fire sealant into the forward end. Lots of info posted by Dan Horton on this including fire tests.

 

[jerry98b]

I’d try to utilize it for something.
You could put in another pass through for wiring, maybe for an oil shutter cable, etc.
If not, I’d just use a nut and bolt and two fender washers to seal it. That way it’ll be there when you need it for something you forgot or decided to add.

Exactly, I started thinking that I didn't want to plug permanently because it would be in a good place for an oil shutter cable if I decide to add one later.