A good TIG welder should be able to do this properly. The joint needs to be ground back at about a 45
deg angle to make a place for a series of overlapping, layered weld beads, so that the weld penetration is as deep
as the metal. I'd ask friends if they know someone who is a TIG welder.
I have a friend who I use when it is really important, but I do my own gas welding and an occasional
TIG weld, but I am still learning TIG, and my own TIG welder isn't set up yet. I have practiced on a
friend's unit, the same model as mine.
Bill