On a 3rd party weld evaluation, if a crack is found in an Aluminum weldment, what is the proper procedure to follow?  Do you cut two more samples from the same specimen?  Or does it flat out fail? 

To give you a quick overview of the failure, It starts at the seam between the two mating surfaces and propagates about .015" into root of weld.  Is there a hard # that states if the crack is X dimension it is a fail?  I'm asking because if you zoom in close enough, wouldn't this crack eventually show up? 

Also what is to be done if the 3rd party evaluation is skewed due to the way the weldment was cut apart, meaning the way it was processed could have an adverse affect on whether there is a crack in this particular joint.