Gas tank fab part 1

I've been thinking about how to go about cutting up this tank for two days now, trying to determine the least amount of cuts and thereby the least amount of welding. This is my first shot at welding up a gas tank and I only have a MIG welder

The pitch of the tunnel makes a vertical cut pretty hard to get straight. I had to use a sawzall just to get in there and sure enough it was uneven, but this it the part of the tank that needs 1/2" of widening to accommodate the 250's wide frame.

The rust on the inside wasn't nearly as bad as it looked from inside the tank

I welded a 1/2" piece of 18ga mild steel to the left side, you can see on the right side that the sawzall didn't cut so straight... unfortunately the tunnel is so deep in the middle/front area that my angle grinder couldn't get in. There's a couple tiny pinholes that'll need patching, but a pressure test when all is done will reveal just how much more work I'll need to do to make this leak proof. I'm going to have to make a horizontal cut to deepen the tank, so I'll fix that gap still

I put a few tacks on the top to hold it together as the widened bottom looked good with the top of the tank in the original position. You can see how the widened bottom affected the front of the tank

I still need to cut horizontally across the tank to deepen the tank by about 2", but that's going to have to wait, my neighbors will kill me if I start up with the angle grinder at this point in the evening. Once that's cut, I'll get a better shot at joining up the two sides of the tunnel area, from the inside of the tank. Then after welding in another 2 inches to deepen the tank, I'll finish the welding on the vertical cut on the top side of the tank and start pressure testing. This is a little intimidating being my first tank job and having to weld something not for structure, but for holding liquid, but I think I'll be able to work through it and have something neat

put it on the bike for fitment and the tunnel area is just right, though the rest of the tank is a little out of proportion

a little work with photoshop came up with this

A little off, but a lot closer to the direction I want to go

more to come when I get some more free time, lately it seems to be harder and harder to find my way to the garage