the weld look good on the surface.....but at the very beggining of the weld you can clearly see the lack of penetration.....
a couple tricks....1" clean the metal very good...any rust or scale will adversly affect the quality of the weld... and 2 make sure the metal is heated up a little....that way it is easier for the welder, at least the little 110v ones to penetrate....this should not be a problem on any decent 220v welder.
Also maybe turn the heat up higher if you can.