Hitting under a golf ball so that it contacts the top of the club leaves a scuff or scratch, better known as sky marks. They're not pretty. Sky marks are most obvious on drivers and fairway woods. The marks are obvious in the paint or enamel on the top of the club. Minor sky marks can be removed with the proper supplies and some elbow grease.
Prepare a work area by spreading out a towel on a bench or table with enough room to lay out the club and your repair items. A bench vice isn't necessary but can help keep the club steady while you work on it. Use some rags or other padding in the vice so the jaws don't damage the club's shaft.
Use a soft toothbrush dipped in soapy water to scrub the sky mark. Use small circular motions as you scrub. This should remove any light surface marks.
Scrub the club in the same manner with buffing compound, for deeper marks. Buffing compound is slightly abrasive and will remove some of the enamel or paint top coating to smooth out the surface. Usually only a small amount of the coating need be rubbed away to remove the sky mark and it will not affect the finish of the club. Rub the compound in lightly, slowly increasing the pressure to remove the sky mark. A motorised buffing wheel can also be used.
Clean the club with a fresh rag and soapy water to remove the buffing compound. Wipe the club dry with a soft cloth.
Repair any paint or enamel removal, that may be more than acceptable, by using car touch-up paint. This paint is very hard and will help the club better withstand the rigours of play. After carefully applying the touch up-paint using the manufacturer's directions, apply a clear spray top coat over the top of the club to restore the original shine.
Many deep scratches can be repaired by a golf club professional and some manufacturers may even repair the club under warranty. The sky mark will not affect the play of the club, but can be distracting during your set up.
It may not be possible to remove deep scratches.