(Very!) Leaky Fabbed Petcock

[Dr. Frankenstein]

What is everybody/anybody using to keep their petcocks from leaking?

I changed out the old petcock on my 305 for a 1/4" round slab of aluminum thinking I would get better adhesion and less leaking...I put a cheap petcock through it and bolted it to the tank with a cork/rubber gasket, and even coated the gasket with some new Permatex fuel-resistant gasket maker.

I thought I had every angle covered, but when I put gas in the tank it literally poured out of the petcock around the base I made, worse than when I simply used the base and the cork/ rubber gasket material.

I have since ground, sanded and polished the petcock area of the tank to a mirror finish, reinstalled a new Permatex-coated gasket and installed the bolts with thread sealant, cranking them and it down with all my might; I thought about using a torque wrench, but didn't want to strip out the bolts.

I plan to leave the whole assembly OFF the bike this time to check it, in case I get another cascade....but does anyone have a petcock/sealant procedure that works?

-John