Canvas chairs usually bring to mind a director's chair or a camping-style chair. However, canvas is a strong fabric that is also found on many metal tubular and swing-type hammock chairs. The seat of a canvas chair can be replaced if you have the right equipment. Oftentimes, the seat will wear out before the frame, but canvas is inexpensive so it is worthwhile to replace the seat rather than discard the chair.
Remove the chair seat from the chair. If the chair is a director's-type chair, you simply slide off the top canvas back, drop the arms and expose the seat attachments. The canvas seat should have two pockets on each side with a stick inside the pocket; these slide inside a groove in the bottom of the chair seat. Lift them out, and remove the sticks.
Rip the seams on the chair seat using a seam ripper. Iron the chair seat flat.
Purchase chair-weight canvas. One way to identify and find replacement canvas is through awning companies in your area. The awning company can suggest the right weight fabric or companies who sell that fabric.
Pin your existing canvas seat as a pattern over your new canvas. Cut and sew the seat following the way the seat was originally sewn. Insert the sticks, and put the seat together so the edge of the canvas aligns with the front of the chair. Fold the arms up, and slide the back fabric in place.
Remove the canvas seat from other types of chairs. Often, canvas is attached through pockets sewn in the canvas over wood or metal chair frames. If the frame has a way to slide the canvas off the frame, then you can resew the seat simply by following the existing seat pattern. If the canvas is sewn over the frame, then you will need to modify the pattern for your attachments.
Rip the seams on your existing canvas seat. Cut a strip of canvas 2 1/2 inches wide and 3 feet long. Fold 1/2 inch of canvas along the length, and sew two parallel seams. Fold 1/2 inch of canvas along the other raw side of the length. Fold the fold 1/2 inch, and sew two parallel seams.
Punch a 1/8-inch hole in the canvas 1/4 inch from the outside edge on the thicker side of the canvas. Add a metal eyelet through the hole. Measure 1 inch along the length, and punch and add another eyelet. Continue the full length of the strip.
Cut a piece of canvas the size of your seat. Add 1 inch to the sides that wrap over the chair frame. Sew your front and back hems following the pattern of the existing seat. Turn the sides under 1/2 inch. Turn the fold under 1/2 inch, and sew two parallel seams. Repeat for both sides. Mark for eyelets 1 inch apart and centred along the length of the sides. Punch and install the metal eyelets.
Cut from your 3-foot strip a length the same size as your chair seat side. Turn under each end, and sew for neatness. Attach this strip parallel to the side 1 inch closer to the centre of the chair than the old seam line on the existing chair seat. Sew on the underside of the chair seat. Sew the strip with the eyelets toward the side, and sew on the thinner side of the strip with two parallel seams. Repeat for the other side.
Place your chair upside-down. Position the seat over the frame. Tie a large sturdy knot in cording, and thread the knot through an eyelet. Lace the eyelets together, and knot the cording securely. Repeat for the other side.
Some sewing machines are not able to sew through three layers of canvas.