Re: Crack in Armstrong Bracket
Anyone who deals with aluminum long enough has cracks. As good as it is for specific purposes, that is what aluminum does, it cracks. Particularly if it was anodized before it was welded. Aluminum has some great properties but fatigue strength is not necessarily one of them.
Strip the paint from the suspected area and do, or have someone do it for you, a dye penetrant check. This will verify there is indeed a crack and determine the extent of it.
Although the crack can be welded over, if it were mine I would have some reinforcing gussets welded in to support the welded over area and to minimize the likelyhood of future cracks. None of this should be difficult for an experienced welder.