If there was any doubt that I'm a hopeless airplane restoration geek, taking many close-up photos of various fuel filler neck grommets on the Oshkosh flightline last summer probably clinches it. Exhibit A: left photo below, of an Aeronca Chief. I even started quizzing Aeronca pilots about where they got their grommets.
I've tried grommets from Univair and Wag-Aero. Univair calls theirs an Ercoupe fuselage tank filler neck grommet (part no. 40430, $12.43.) Wag-Aero has pretty much the same item, but they call it a "Piper style filler neck gasket" (part no. E-421-000, $4.50, "Outer diameter 3-3/8", inner 2-1/8" and 1/2" thick. Black. Not compatible with auto fuel.")
But I haven't been happy with these, because they're a spongy material (neoprene?) that seems to degrade over time, even with applications of Armor-All for UV protection. And they just sit on top of the boot cowl without effectively sealing the opening around the filler neck, so water from the inevitable Oshkosh thunderstorm will leak into your cockpit unless you caulk or glue the grommet to the boot cowl. And fuel will drip into your cockpit if you or the lineboy over-fill the tank (and who hasn't?)
There were some other suggestions in an April 2007 thread here:
4-22-2007
astjp2
The WAG grommet does not do well with auto fuel, Try a GF22 by metro molded products. They are made from rubber and you can trim the inner supports on the bottom to give you more clearance for your fuel cap. Good luck Tim
http://www.metrommp.com/productimages/640/GF22.jpg
4/24/2007
You can also use the bottom tank seal that goes in a toilet from your local hardware store. You will have to trim it a little.
__________________
Wayne Melvin
N43112
TF376
And of course you can slice a ring off a black rubber toilet plunger.
But I recently stumbled across the source for the Aeronca-style grommets on an Aeronca forum. An Aeronca pilot in Texas had a bunch of them custom-made years ago, and is still selling them for $30.50, postage included:
David Jackson
5808 Terra Drive
Arlington, TX 76017
817-465-7253
I bought one from him, and am disproportionately, geekily, thrilled with it. The two middle photos below show it next to my former Univair/Wag-Aero one. It has a lip that goes inside the boot cowl, like a proper grommet, for a good seal. It fits so snugly around the filler neck that it required silicone lubricant to slide it on. And, as you can see from the right photo below, its lower profile won't interfere as much with the rear fitting for the cowling slip seam hinge (whereas I had to square off the front edge of the Univair/Wag-Aero one). I didn't even hesitate to slightly enlarge the hole in my boot cowl for it.
Jeez, six paragraphs about filler neck grommets. What a geek.
I've tried grommets from Univair and Wag-Aero. Univair calls theirs an Ercoupe fuselage tank filler neck grommet (part no. 40430, $12.43.) Wag-Aero has pretty much the same item, but they call it a "Piper style filler neck gasket" (part no. E-421-000, $4.50, "Outer diameter 3-3/8", inner 2-1/8" and 1/2" thick. Black. Not compatible with auto fuel.")
But I haven't been happy with these, because they're a spongy material (neoprene?) that seems to degrade over time, even with applications of Armor-All for UV protection. And they just sit on top of the boot cowl without effectively sealing the opening around the filler neck, so water from the inevitable Oshkosh thunderstorm will leak into your cockpit unless you caulk or glue the grommet to the boot cowl. And fuel will drip into your cockpit if you or the lineboy over-fill the tank (and who hasn't?)
There were some other suggestions in an April 2007 thread here:
4-22-2007
astjp2
The WAG grommet does not do well with auto fuel, Try a GF22 by metro molded products. They are made from rubber and you can trim the inner supports on the bottom to give you more clearance for your fuel cap. Good luck Tim
http://www.metrommp.com/productimages/640/GF22.jpg
4/24/2007
You can also use the bottom tank seal that goes in a toilet from your local hardware store. You will have to trim it a little.
__________________
Wayne Melvin
N43112
TF376
And of course you can slice a ring off a black rubber toilet plunger.
But I recently stumbled across the source for the Aeronca-style grommets on an Aeronca forum. An Aeronca pilot in Texas had a bunch of them custom-made years ago, and is still selling them for $30.50, postage included:
David Jackson
5808 Terra Drive
Arlington, TX 76017
817-465-7253
I bought one from him, and am disproportionately, geekily, thrilled with it. The two middle photos below show it next to my former Univair/Wag-Aero one. It has a lip that goes inside the boot cowl, like a proper grommet, for a good seal. It fits so snugly around the filler neck that it required silicone lubricant to slide it on. And, as you can see from the right photo below, its lower profile won't interfere as much with the rear fitting for the cowling slip seam hinge (whereas I had to square off the front edge of the Univair/Wag-Aero one). I didn't even hesitate to slightly enlarge the hole in my boot cowl for it.
Jeez, six paragraphs about filler neck grommets. What a geek.
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