Welding a New Fuel Tank

[Industrial Toys]

That's kind of what I did with the last one. I guess MIG could be different from stick, no? You could have some flux plugging a leak that then breaks off.

 

[CADplans]

Why not order one of these??

Tanks Archives - Rick's Tank's

 

[Gary Fowler]

An easy way to find leaks is to just "paint" the seams on the inside of the tank with diesel and then wait a couple of days to see if an oily spot surfaces. That is the acceptable way API specifies for testing large storagestanks for leaks prior to doing a full liquid filling of the tank for strength. For large oil storage tanks, we just used a garden sprayer and sprayed every joint, then waited a week or so. Dust would collect on the oily outside surface making it easy to see any leak.
If there is any pin hole or embedded piece of flux in the weld that may leak later the diesel will penetrate thru it.

For the small sized tank you specified, just place a quart or so of diesel in it and slosh it around to coat the inside of the tank then wait a few days, then look for diesel residue.

NOTE: take care to not get any spilled fuel on the outside of the tank. Scrub outside seams with soap and water to make sure no oil is on the outside.