To get the tank low, and get rid of the large pump mounting hole I had to cut the bottom out of the tank. easy enough with one of those 1mm cutting disks which I seem to use a lot of these days! I needed to make the infill patch and contour this to fit the hole. to make this easier I profiled it to the right shape by cutting some wood and pressing it to shape in the vice, then a bit of planishing to get it to the final shape.
The aim is to get the gap as small as possible to facilitate a nice weld. I used some 1mm mild steel plate which matches the thickness of the tank, so TIG welding is no problem on a low amp setting. I used a couple of magnets to position it before adding a few tacks all round. At this point I ran out of Argon... The last refill I bought was £65.. now its £104!
The outlet is made, but I need the filter fitting on the bike first so I can position it to get the pipe runs neat. Once this is welded on I can leak test.