Roll grinding to finish corners

A technique I call roll grinding is used to finish corners to match bend radii. Long weld seams that need to be rounded can be handled using a rolling technique with the disc grinder. It takes a little practice, but once you’ve mastered it, the results look just like a formed corner.

In one shop I worked at, we roll-ground miles of seams. Good welding technique can minimize the amount of metal removal in this finishing method.

All images courtesy T. Lipton

When roll grinding, first deck off the weld flush against two intersecting right-angle surfaces.

The weld should first be decked off flush against the two intersecting right-angle surfaces. For bumpy welds, I sometimes take a few light faceting passes to even everything out.

If you’re right-handed, stand with the weld to your right. Your right hand is the balance hand that supports the weight of the grinder while your left hand does the precision rolling motion. The wheel, or disc, should be kept as flat as possible on the weld seam. Very little pressure is needed to do the actual rounding. Think of your right hand as the pivot holding a round object, like a motorcycle grip or a piece of round handrail. As you sand, step slowly backward along the seam.

For bumpy welds, take a few light faceting passes to even everything out before roll grinding.

The rolling passes should overlap by three-quarters of the disc diameter or more.