Good evening rdavid,

WELCOME TO THE AWS WELDING FORUM!!

The first thing you need to verify for yourself, not necessarily for us, is the material thickness.  Then you need to make sure if you are dealing with a primary member under cyclic conditions.  It is required to be called out on the drawings if it is.  This is not something you guess at, the engineer makes the call and makes it clear.

Then, if 6.1 (7) Undercut, A) applies it goes like this:

If the undercut is along the entire edge of the weld it can be 1/32" deep for that run.

If the undercut is on a stiffener plate, continuity plate, connection plate, along a groove weld, etc and is not over 2" in length for any 12" worth of run then it can be 1/16" deep instead of limited to the 1/32" for the entire length.  That means that if your part is 36" long and you have 3 areas of undercut that are separated and in one of the differing 12" segments then the undercut can be 1/16" deep.  But, if the undercut runs along the entire leg of the weld for 36" then it can only be 1/32" deep.

Now, the undercut cannot be 6" long and count as being 2" in 12" just because the entire length is 36".  I would not even allow 4" continuous and say, 'but the length divides here and only 2" of it is in this 12" of weld.  Where ever the undercut is can only be 2" long and then must have the remaining distance to space it for a 12" section.  Similar to the way you would measure intermittent fillet welds.  2 on 12 means 2" with a 10" space then 2" more; or, said more technically, 12" on center with 2" length. 

Did that make sense? 

He Is In Control, Have a Great Day,  Brent