I hooked the fuel tank up to a vacuum pump and fitted a low range guage to one of the tank fittings. I pulled a 1″ WC vacuum on the tank and sprayed the Loctit 7649 primer on the leak seam. I waited for a few minutes for the primer to work its way into the leak and then dabbed a few drops of Loctite Green 290 on the leak area. I left the vacuum on for a couple of minutes and them shut the pump off. I let the vacuum bleed off and then left the tank to cure for 4 hours. I repeated the pressure test with snoop and the bubbles did not appear. I re-installed the tank the following day. The installation only took an hour to complete. I picked up a very compact 1/4″ ratchet drive that helped speed up the job.

Fuel was added to the tank and after 24 hours there was no sign of any fuel leak. Success! Now on to fuel flow and weight and balance tasks.