I think the grey sealer is what is used to seal tanks in the Mooney wet wing. It is Pro Seal (PPG product): https://www.aircraftspruce.com/catalog/pnpages/09-38560.php?msclkid=2a76294add861060be6b4a5968ac2541
It is also available from spruce. It is a two part sealer so does harden. This can leave it more brittle than the Buna slosh that I mentioned before.

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Rick Hole via groups.io
Sent: Saturday, September 3, 2022 11:15 AM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Fuel tank failure after one week of testing!!! 😤

In my days with Velocity, the tanks (main tanks and header) were made with EZ poxy and further were coated with a fuel sealer, light grey in color, a two part product I can't remember the name.  Velocity did not consider EZ poxy sufficient especially if auto fuel were to be considered.
We must also look ahead to the likelihood that leaded avgas will be phased out sooner rather than later.


Rick Hole