SEALANT FOR FUEL FITTING??

Ok, I know most fitting are flared or a compression fittings for most fuel lines,. but I need to install a brass 1/4 hose barb fitting into a plastic gas tank for a tractor project. I had It drilled and tapped, ready to go, but want to put a dap of some type of sealant just for a safety measure.
Any ideas on a good product that will seal and stand up to gas?

Thanks
Marty

Black Permatex Form A Gasket works good, andgit doesnt get hard.

I had thought of permatex silicone as I have some, it's just going to basically be a thread sealant anyway, just an insurance, it's a pretty tight fit already.

Ive used the black gasket maker on hydraulics and diesel on the river. Its not the black RTV, but I believe that the RTV is gasoline resistant too.

Couple guys from a tractor forum clued me in on this stuff, found it at Advance Auto for $5.49. One guy sealed a tractor gas tank with pinholes couple yrs ago, still holding. Another guy used it to seal a brass float inside carb tractor carb. Gonna give it a shot.

I always used JB Weld

I'm using on plastic tanks and I've seen JB Weld stay hard and then crack off. These plastic tanks expand and shift. This stuff stays slightly plyable like RTV so hopefully it will work.

gotcha ya.