lack of fusion in the root pass, I see it on occasion. Make sure the WPS the welder is using calls for the correct amperage range and polarity, then make sure he has the machine set right.
Now of course you can do this after he took the test and bust him out for not following proper procedures and protocalls, but depends on how strict your program is.
When I give atest I give the welder a hard copy of the WPS,then I ask them "have you worked with a WPS? do you know what it is?" then they say no.
Then I explain to them what it is, how it works and what the info on it means and how to use it. Then I explain to them how to set the machine, I don't do it for them...if they want to be a welder, they need to know how to adjust it, not just weld with it.
Some people are open and undertand, others don't get t, and others are too stubborn to listen. Those guys always fail the first time.
They don't have 20 yrs experience,,,they have one day of experience doing the same thing everyday for 20 yrs.
There's a difference.