Fuel tank repairs

Just come back from week in Cornwall to find half a tank of oily mess under series 3 LI150.
Taken stainless tank out and on the centre of the rear seam it seeps fuel when I tilt tank back.
Can this seam be welded, or is there another sealing solution?
Taken stainless tank out and on the centre of the rear seam it seeps fuel when I tilt tank back.
Can this seam be welded, or is there another sealing solution?