Perhaps, but your statement doesn't show all the prep work/purging that you did to get it safe, which could be misleading to someone reading this. Many people have died welding on fuel tanks (even diesel), it is dangerous/lethal if not done properly (just use google to see all the fatalities). Here is just one sad example:Oh please. I have MIG welded on gas tanks that had fuel in them the same day.
FACE Program: California Case Report 07CA006 | NIOSH | CDC
On May 19, 2007, at approximately 11:00 a.m., a 25-year-old Hispanic welder died from an explosion of a fuel tank on which he was welding.
www.cdc.gov