Should I Remove Mill Scale Before Welding?

Also with this process you have more arc spread (read: a higher arc tension) which makes the weld flow slightly better. Again, the weld remains too convex and there are many silicates on the weld. In all cases it remains necessary to remove the mill scale before welding.

Can you weld through mill scale?

You can use SMAW, or stick welding, to weld through mill scale because the electrodes have deoxidizers and a slag system. Some stick electrodes are designed to offer better success when welding extremely thick scale or on very dirty base material.

How long does it take vinegar to remove mill scale?

In around two hours, the parts of the steel that were completely exposed were free of scale. The undersides had to be rotated up so the acid could get at them.