I did a bit of diy arc welding 30 years ago.then dicided to make a small boat trailer came out good still together.then 10 years ago I made a work trestle still together.then a few months ago I bought a ac buzz box welder lighter more portable than my transformer arc welder which is heavy.i find it hard to strike an arc and the welds are very bad.why are the buzz boxes hard to use.i think I will get the old welder out and weld some 50x50x3mm tube.how do I prep the tube.i want to make up a square frame.do I need to grind the edges at 45 so I can grind the welds flat.any tips will be gratefull.thanks