I did plan on welding them all the way around but like you said, its very time consuming. I ended up doing a weld every couple inches before putting the seam sealer down and a couple years later it all still seems to be holding up pretty good.Havent seen that before pretty good idea. I ended up taking the very time consuming route and welded mine all the way around instead of just spot welding in a few spots. Your way would be WAY faster!!