This housing version has a bit of a stress riser where the box is cut away and the bents are welded. Noticed some cracks and did the usual stop drill and v groove out. All is well until I decided to look inside the welds by polishing the profile of the crown. Will likely run a gusset to mitigate the probable recurrence. Hoping this repair weld will buy some time. V groove w rotary file Ready to weld w 7018 and weld w porosity Flap disc works well to remove splatter, blend arc strikes, and remove ripple to allow fairing....and it also allows a little peek inside the weld. Thinking the casual spray w carb cleaner didnt adequately clean the crack and should have maybe ran the torch over it....too late now, the cooties are in the metal.
You can take a tig welder, turn the heat down as low as it will go and still melt a tiny puddle... you can then chase those little "cooties" away.