Best Fuel Resistant Silicone Sealer??

[70TWO NOVA]

Hey guys,
Im getting ready to finish up my EFI fuel tank conversion and will be needing to seal the top portion of the tank. What is the best silicone sealer to use that is completely fuel resistant. I want to make sure I dont get any vapors or liquid fuel leaking out. Any info is greatly appreciated.

This is what Im sealing;

https://static1.pt-content.com/images/pt/2012/12/gastank5-1.jpg

[TheJDMan]

I think you would be better off soldering that seam. A good quality flux core solder or a stick of body filler lead and a propane torch would work. Clean the seam first with an acid etching cleaner.

[RSX302]

Silicone?

I have to second TheJDMan...weld or solder

[70TWO NOVA]

not necessarily silicone, but something to seal that isn't permanent like welding or soldering but seals well. Im going to need to open the tank up from time to time for maintenance or replace the pump if and when it goes bad.

[RSX302]

It's harder because it isn't a flat surface but you can try making a thick (1/8") backing ring, drill and tap and tack weld. Top side, weld a over lapping ring to the inner (removable plate) so a gasket can be sandwiched between. Looking at a button head screw about every one inch for a good seal.

[70TWO NOVA]

this is what i have so far. welded a lip for the removed section to sit on, then fasteners along all the edges. I was wanting to put a good sealer between these surfaces then screw it down securely

https://static1.pt-content.com/images/pt/2013/01/gastank11-1.jpg
https://static1.pt-content.com/images/pt/2013/01/gastank12-1.jpg

[70TWO NOVA]

https://static1.pt-content.com/images/pt/2013/01/gastank6-1.jpg
https://static1.pt-content.com/images/pt/2012/12/gastank7-1.jpg

[RSX302]

Ahhh..now we are seeing the whole picture. You were already there. Didn't see that in the original post.

Still, I wouldn't use just silicone to seal. Hopefully the gap thickness is consistant around flange. I would use a rubber gasket.
Maybe you can use a little Permatex to it to aid with the seal with a rubber gasket. It is only resistant.
http://www.permatex.com/products/product-selector?view=productcategory&id=172