I note there is trend towards teaching yourself to weld particularly with mig. This is fine as long as it is not structural/load bearing. As a qualified welder it frightens me when people get a welder and build things like car ramps, trailers, trusses etc. Remember you are not just potentially risking yourself but others, your kids etc. Trust me, a weld can look bloody good but it can be very weak through lack of penetration or porosity or severe undercut and so on. If not a course, learn from someone that can weld or at the least get your welds checked.