You can recover damaged RV cushions with upholstery fabric. Most cushions will require about one yard of fabric. Get enough fabric by measuring both the length and width of the cushions before buying the fabric. You will also need a heavy duty sewing machine to make the new covers. If you cut the fabric for the new cushion covers a few inches longer than the original cushion covers, you can avoid hand-sewing and do the whole recovering job using the sewing machine.
Remove the original cover using the seam ripper to cut the threads on one end of the cushion. Peel the cover off when the end is open and turn the cover inside out. Mark corners and any other unusually shaped areas on the cushion using the tailor's chalk. Use the seam ripper to cut the rest of the threads holding the original cushion cover together.
Spread the new fabric face down on the table and place the original cover face down on top of it. Mark around the original fabric using the tailor's chalk. Make sure you transfer any other marks you made on the original RV cushion cover to the new fabric.
Cut out the new fabric cushion covers using the scissors. Finish the raw edges all the way around the newly cut fabric using a zigzag or over-lock stitch on the sewing machine. This will help prevent fraying on the seams of your newly recovered RV cushions.
Fold in corners according to the tailor's chalk marks you made and transferred onto the new fabric. Make sure the fabric's right sides are together and sew them using a tight stitch on the sewing machine.
Pick one edge or end to leave open. A seam that will be hidden against the body of the RV will be the least noticeable. Sew the remaining sides together on the sewing machine. When you sew across an intersecting seam, push the seam to one side and keep sewing.
Turn the new cover inside out and slide it over the RV cushion, turning it right side out as the cushion fills it.
Fold the raw edges along the opening under 1/2 inch and use the upholstery pins to hold the folded fabric together. Top-stitch the edge closed using a tight stitch on the sewing machine, sewing 1/4 inch in from the folds.
Use a 1/2 inch seam allowance when sewing upholstery fabric to recover RV cushions.