How to Fix Metal Pitting

Clean the metal surface thoroughly with a scrub brush and a mixture of dish soap and warm water. Dry the metal completely using a soft cloth.

Secure the metal between the clamps of a bench vise. If your metal object is too large to secure with a bench vise, stabilize it with a ratcheting pulley or weight it down with cinder blocks.

Attach a 320-grit sanding disc to your angle grinder. Depending on the type of grinder you're using, disc installation procedure may vary. Refer to your tool's instruction manual for more specific instruction.

Put on safety goggles and dust mask. Turn on the grinder and set it to its medium speed. Touch the rotating disc to the pitted surface of the metal and apply firm even pressure. Move the disc across the pitting using a slow, side-to-side motion.

Turn off the grinder. Saturate a cloth with penetrating lubricant and wipe the metal free of dust to check your progress. If pitting is still visible, continue sanding until it appears smooth and the pitting is gone.

Wipe the metal completely clean with your saturated cloth. Attach a buffing wheel to your angle grinder.

Apply a generous layer of metal polish to the surface. Turn on the angle grinder and set it to its medium speed. Move the buffing wheel over the metal surface, again using a smooth side-to-side motion. For a high-shine finish, increase the speed of the grinder.

Wipe the metal clean with a damp cloth once the desired polish has been achieved.