Sounds like heresy, but Home Depot sells aluminum angle if you don't want to wait for Aircraft Spruce.
Sounds like heresy, but Home Depot sells aluminum angle if you don't want to wait for Aircraft Spruce.
Easiest way to tell the difference. Aircraft extruded aluminum angle has a curved radius at the inside angle; hardware store aluminum has a square inside angle.
I understand the concerns, but depending on the application Home Depot is sometimes a good option. In the ultralight world it's fairly common.
I wouldn't build a spar out of Home Depot, but brackets and such are fine. Like you said, make a judgement call based on an evaluation of criticality. I'm a nuclear engineer with 40 years in the industry. Not everything is safety related or we never would have been able to afford making a megawatt!
Play nice!