List the brand of your hot water tank, do you know how bad and where the leak is? Post a photo as well and maybe you will get better answers. If the tank is under pressure when the water is being used, so sealing could be a problem. Also need to know if you are using a water pump when you turn the water on or do you have a pressurized system that runs off a compressor? Answering these questions might give you more answers than questions in return.
We removed our original 1963
hot water tank, and took it to a professional welder who made sure all was sealed and perfect!
Mrs. NorCal Bambi (traveling in S Tardis)