two thoughts (1) how good are you at welding? lap or flange joints are more forgiving.(2)if you want to butt weld get some copper pipe from home depot or something like that and hammer it flat.you can use this to "back" the weld to reduce burn thru. the weld puddle will not stick to the copper and it acts as a heat sink. practice on some scrap and see how comfortable you feel.also go slow 1/4 inch beads about 1"-1 1/2" apart to prevent or reduce warping.others will chip in i'm sure because i know i've forgot something good luck tom
