[Land-speed] rollcage welding

[Benn]

Planning the rollcage for the MR2, and want to plant the main hoop as far
outboard as possible.  BUT, since it's behind the door opening, there is no
way to weld the horizontal side (door) bars fully to the main hoop if it is
hard against the interior body panel.  So, the question is, what is the
minimum clearance I can get away with and allow a good welder (not me) to
still be able to weld the bars around their full circumference?  A half inch?
full inch?
Benn