I also would add when you grind out a crack. At the ends of the crack first thing is to drill a hole on either end straight thru the metal. It can be small like 1/8” but make it proportional to the crack. This stops the crack from going further. I typically find the end of the crack and using it’s projected path drill about 1/2” to 1” past what you can see because cast (steel or iron) cracks thru the grains of the metal.
