Woof. Cracks in welds is always a bad sign of poor engineering management and quality control. Getting welders that can consistently produce xray quality welds

Woof. Cracks in welds is always a bad sign of poor engineering management and quality control. Getting welders that can consistently produce xray quality welds isn't hard or even expensive. You just need to get good people and treat them well. As for discovering them you can xray all the welds during fab to ensure nothing like that makes it out. Though depending on what surfaces you were joining you can often just grind the weld out and try again, though this is pain in the ass with full penetration welds. My brother runs a high end fabrication company (the kind you might hire to fabricate a piece of your rocket) and such things would never leave the floor of his shop.