So two days ago i took my tank off with the intent of grinding it down to clear up the rust that has occured from little rocks hitting it so all went well (so i thought)   got it painted again and was excited to get it on my bike and cruize but when i went to put gas in and i heard a stream so im lookin at the carb making sure i didnt have a brain fart and leave the fuel line out but no on the bottom weld it had a hole, and inside you could see a bunch of rust!!!  Sooo now its at the shop getting a acid cleansing and getting welded back up. Going to cost $50 CND but hopefully all goes well, guy said well we dont know... the acid could chew away more then we think!! so fun  :'(

Have them float the base of the tank with a really high quality body solder... Had a 1971 tank done that looked like a pasta strainer, 13 years later it holds gas just fine. Ugly as sin, but since the holes were on the bottom of the tank, who cares.