You can buy kits that contain a mild acid to clean the tank and a liner. I've used that type of kit in the past but I discovered that using muriatic acid is much quicker. Also note that because it's a much more caustic acid the safety requirements are more stringent. I used muriatic acid to clean my '38s tank because replacement tanks are not available. I then dumped several gallons of soda water into the tank to kill the acid, rinsed well, let it dry and coated with Redkote liner after brazing the larger holes shut. Five years now and no issues.
Last edited by Tiny; 11/05/2011 12:09 AM.