9.4.5.E.6. (I think... I suck at following that BS) I'll have to dig for the AWS code, but can guarantee that it's against the code to grind a weld, but for now, this'll have to do:

6. Welding shall conform to American Welding Society D1.1:2002, Structural Welding Code, Steel Chapter 10, Tubular Structures. Whenever D1.1 refers to "the Engineer" this shall be inter-preted to be the owner of the vehicle. Welds shall be contin-uous around the entire tubular structure. All welds shall be visually inspected and shall be acceptable if the following conditions are satisfied: a. The weld shall have no cracks. b. Thorough fusion shall exist between weld metal and base metal. c. All craters shall be filled to the cross section of the weld. d. Undercut shall be no more than 0.01 inch deep.