Danny hooked me up with this 80's roadster tank to cut up. I like the look of this tank but it has way too much meat in the middle so i am going to narrow and pinch it. This tank seems like it could use some extra style as well so i am going to actually run it as split tanks to pay homage to the split tanks that have come on Harley Big Twins for decades.
After drawing the centerline (hardest part of the job) run the tank down the band saw.
Remove the filler cap stamping, since the tank is shrinking you can give your self some extra material on the stamping so that you can hammer and dolly the joint after welding the stamping back in.
Here the tank is split down the middle sans cap stamping.
Took out 2in up front and 3.5 in the rear. Some people prefer to cut the tank in half in two cuts so that when you are done cutting the narrowing and pinching are already done. I generally tend to cut it down the middle and then hold the tank halves together at different angles so that I can see what my eye likes best.
Wire wheel the paint off, burn off the lead, hammer out all dents, trim a bunch of times until they fit together nicely..... then weld stuff.