Pneumatic needle peening

Needle descaling is basically tapping the surface with fine steel needles driven by compressed air. This removes scale, rust, and slag, especially on weld seams and in corners where you can't reach with a grinder. It doesn't really smooth transitions but leaves a rough, uniform texture that's good for the next coat. Just be careful not to stay too long in one spot and remove too much material, otherwise you'll dig a groove. For weld preparation, it's great, but if you need a smooth surface, you still have to grind.