welcome to the world of locked diff, good job. A little secret to make cleanup a snap, spray dry graphite lube all over everything after you clean all the oil out, once the graphite dries (almost instantly you can watch it happen) lightly wipe it with a non abrasive rag or papertowel. Don't wipe it off just kinda polish it shiny. Once it's all shiny weld it up like normal, you can weld through it without getting porosity but the splatter won't stick. Once your all done just spray it out you might have one or two little spots you'll need to scrape but thats it. The graphite can stay inside too it won't hurt anything.