The fabric on sofa arms often wears faster than the rest of the sofa. Repairing your sofa arms may seem difficult at first, but often you can replace the damaged fabric with new fabric and prolong the useful life of your sofa. It is likely you will be unable to match the fabric on your sofa, so spend some time selecting an upholstery fabric that will look good with the rest of your sofa.
Clean and vacuum the entire sofa. Remove the cushions and clean deep in the cracks. Shampoo the sofa with an upholstery shampoo. This will remove the dirt from the fabric and often brighten the color. Take a sample of the sofa color with you when you buy upholstery fabric for the new arms.
Remove the arm fabric by finding the seams that shape the way the fabric drapes over the arms. Carefully use a seam ripper to open these seams. Follow the seams around until the arm fabric pieces can be removed. Note how these pieces were attached to the sofa, including the location of tacks or staples. Iron your fabric pieces so that you can use them as pattern pieces for the new coverings.
Repair the surface of the arm. Glue foam over the arm with a spray adhesive. Shape and trim the foam with an electric carving knife. Cover the foam with a layer of quilt batting glued or tacked to the sofa frame. Trim away excess batting for a smooth arm surface. Repeat for the other arm.
Fold your new upholstery fabric in half and pin your pattern pieces to the fabric. Cut around each piece, adding 1 inch in all directions. This will provide a margin of error if you need to modify the piece when attaching the fabric to the sofa.
Sew any seams you can on your sewing machine. Fit the cover to the sofa. Staple or tack the fabric to the sofa frame where possible. Hand stitch seams to the old fabric of the couch using a curved upholstery needle and matching thread. Use small cross-over stitches, evenly spaced apart for strength and a nice appearance. A cross-over stitch requires both seam allowances to be folded under with the folded edges barely touching. Bring your threaded needle up from the underside of the fabric 1/8 inch from the fold. Pull the needle and thread snug. Cross over the two folds, and pierce the other fabric fold 1/8 inch from the edge. Bring your needle up 1/16 inch from your first stitch and continue. Repeat for the other arm.