Chuck Bollinger wrote:

Anyone know of any way to use some sort of space-age plastic and
space-age adhesive to patch the top of a stainless steel diesel fuel
tank? Almost no fluid pressure is involved, and it seems to be overkill
to remove the tank because of a 3" hole. The patch, though, would have
to include the filler hose attachment tube.

A 3-inch hole is a bit large for a mechanic in a can solution. If you
have access to the top you are far better off to mount a new flange and
replace the filler tube.

If the old filler tube cracked due to vibration or flexing, there is
nothing in a can or tube that will solve the problem. Fix it correctly,
fix it once, fix it safely.

Rick