All welds are "strong" right when you finish, but true strength has to withstand the stresses assosiated with use: Vibrations/ Torsion/ Heating and Cooling...Well I just made a few.. I definitely need to practice.. but the welds are strong. I welded a 3/8's plate to a 2 x .120 wall square and its ugly.. but its strong.Now to work on the pretty part.