Mounting bulkhead fittings on the belly - drill 2 smaller holes or 1 big one?

[moespeeds]

I need to mount a bulkhead fitting on the belly of my RV8 to vent my EXT900 battery.

I have a single fitting from Earthx that requires a 1.125" hole that mounts both fittings. It's a screw type bulkhead fitting.

Alternatively, I could mount 2x .25" fittings that would require a 5/8" hole for each.

The holes would be on the bottom, around the aft baggage compartment. The aircraft is finished, painted, and flying.

Thoughts?

 

[Desert Rat]

Thats not much bigger than a lot of antenna holes. If it were me, I'd just drill the hole. Even if you need a doubler, you'll never see the extra unpainted rivets on the belly.

 

[moespeeds]

I guess my question is, how do I know if I need a doubler or not?

 

[PaulvS]

Doubler

If in doubt it would be easy to fit a doubler by cutting a "washer" ID 1.125" OD 2" to help spread any load. It appears that the pictured fitting would clamp the doubler in place. That's my $0.02 thoughts.