Hello I have finishing the fuel tank of my ducati project, It’s made of fiberglass and kevlar, with an especial resin to support gasoline.
But now I have the problem to fix the filler neck. I was thinking to use epoxy glue or sealed rivets, or both. What do you think?
Maybe a black sikaflex would clean up well and be a nice finish assuming there is one suitable for fuel contact? No rivets required.
Other things that will stick well but maybe not clean up so well cosmetically are toughened epoxy glue or methacrylate glue like Plexus.
Regular epoxy glue may be a risk for releasing from the aluminium, even if riveted it could still possibly release and leak.
Is not Aluminium, I think is steel, I forgot to tell that.
I would recommend Hysol 9460. The technical data sheet shows 100 per cent strength when exposed to petrol/gasoline. As you know, preparation is the key to achieving a good bond. I imagine they supply it in 50ml units, but you’d need a dispensing gun. The tank looks nice, could you post more photos and your method of construction.
For me steel is the same as bonding to Alloy.
The steel filler may need some kind of finish or paint to keep it from rusting and stay looking good cosmetically.
Hello, I forgot to tell you that I used to make the fuel tank, vinyl ester resin. I red that epoxy (glue) don’t bond very well to vinyl ester, is it correct? 
Epoxy glues stick well to vinyl ester
How did your fuel tank work out? Did you attach the filler okay?