Help Welding a Welder Cart

[EdK]

Question. How do I T-weld square tubing? With the radius' on the corners, there is a gap where there is no metal to metal contact so I can see easily blowing through. The only way I can see closing that gap is to form the end of the tubing to match the radius' and that seems like a whole lot of work. This is 1 1/4" 14 gauge (.083") square tubing. See attached sketch.

Ed