Hi Loren, I feel you're in a bit of a panic there.
TECK:My concern is that the weld is already performed on the paper thin aluminium tank.
If it's your original Warrior tank, it won't be aluminium.
If you look at the photos I took, the shape you are looking for won't work that easy just like btk572 suggests...
btk572:it looks to me that the painted tank has had alot more work done to it and probably was a real stretch and not a cosmetic stretch
to keep the shape going even all the way it will end up a very long tank.
you can see the original tank shape through the white outline Loren.


as for sealing the inside, I would not go there...IMO... There is no room to see if ALL the surfaces inside the tank will be covered.... If you miss an area, the whole lot will peel in stages and clog the filters for months, even years after. Then it's cut the base off the tank and blast the gunge out. ....Ive seen it happen a few times on tanks I've had to paint.
Gav.