How to Make a Sandbag for Metal Work

By Sean Chappell

Updated September 26, 2017

A sandbag softens the blows of a hammer to sheet metal.
i blacksmith working image by pixelcarpenter from

Sheet metal is a thin, flexible metal that can be shaped into panels and used in the automobile industry. On occasion, metal panels are damaged in traffic accidents and require bodywork. These metal panels are repaired by being beaten back into shape with a hammer or mallet. An effective and inexpensive way to support the panel during metal work is to create a sandbag. Made out of leather and filled with fine sand, the sandbag cradles the metal panel and allows it to be formed into a curved shape without damaging the surface.

Place the piece of cowhide leather on a flat surface. Place the piece of suede leather on top of the cowhide. Use barge glue, or another type of leather bonding glue, to seal each of the inner edges of the sandbag. Glue three of the four edges one at a time, being careful to not leave any area unglued. Glue the fourth edge, except for a 1 inch area in the corner, which will be used to pour in the sand. Allow the glue to dry overnight.

Pour a 25 lb. bag of fine sand into a cardboard box, leaving it uncovered. The sand must be completely dry before you pour it into the sandbag, so allow it to dry for 48 to 72 hours. Stir the sand two to three times a day; any moisture in the sand will absorb into the cardboard. Make sure to allow the sand to dry indoors only.

Place a funnel into the unglued corner and pour the sand into the sandbag. Pour about three quarters of the sand into the sandbag, adjusting to your own preference.

Seal the 1-inch opening with glue. Double-stitch the sandbag with heavy duty stitching to reinforce the seams. Place the suede leather side of the sandbag face-up before hammering the metal panel.

Items you will need

  • 18-inch square of suede leather

  • 18-inch square of cowhide leather

  • Barge glue

  • Heavy-duty stitching

  • Needle (or sewing machine)

  • 25 lb. bag of fine sand

  • Cardboard box

  • Funnel