Glue may be all you need to repair a small tear or surface cut in leather, if you use specially formulated leather glue. This kind of glue will remain flexible and will not crack when dry. You can also use a brand of contact cement that is suitable for leather, information that is listed on the bottle. You can use glue to mend surface cuts in leather goods ranging from furniture and car seats to clothing and bags. If the cut is deeper or has ragged edges, you may need to fill or patch the hole as well.
Simple Surface Cuts
Wipe the area around the cut with rubbing alcohol. Use a soft cloth to apply the rubbing alcohol. This will remove grease and dirt, and will ensure that the glue and any colorant you use will adhere properly to the leather.
Pinch the leather on either side of the cut between your finger and thumb to raise and expose the cut fibers. Snip off any frayed fibers with the scissors.
Put a little glue on the end of the scalpel or toothpick. Apply the glue along the cut surfaces. Warm the glued area with a hair dryer if necessary to make the glue tacky.
Push the cut edges together gently, and hold them in place while the glue sets. Use tape if you find it difficult to keep holding the edges in place. Press the join flat using the blunt end of the scalpel or toothpick. Wipe off any excess glue while it is still wet. Let the glue dry completely, in accordance with the instructions on the bottle.
Apply leather dye along the join if it is conspicuous. Spread thin coats of dye across an area larger than the original cut to blend the dye into the original color of the leather. Dry the dye between coats with a hair dryer. Rub with a cloth or fine-grit sandpaper after drying to restore the leather finish or texture.
Rips, Holes, Burns and Deep Cuts
Sand the area around the hole or tear if grease and dirt have built up. Clean off the residue using rubbing alcohol on a soft cloth.
Trim frayed or worn edges using the scissors or scalpel.
Insert a canvas sub-patch behind the hole using tweezers, and smooth it flat. This will form a backing for the leather.
Apply glue to the underside of the leather, between the leather and the canvas patch. Use a palette knife, scalpel or toothpick to apply the glue depending how large the hole is. Make sure you coat every edge of the leather with glue. Warm the glued area using a hair dryer or other heat applicator, if the manufacturer's instructions say the glue needs heat to activate it.
Press the leather onto the canvas. Keep pressing until the glue has bonded - the instructions on the bottle will tell you how long this takes. Leave the glue to dry completely.
Spread heavy filler into the hole if you need to level the surface. Build it up in thin layers, drying between each layer. Apply colorant to the filler and surrounding area in thin coats. Let each coat dry between coats. Once dry, sand the filler smooth.
Patch over the hole with a matching piece of leather. This is an option if the tear is very deep or wide. Put glue around the hole and press the patch into place. Let it dry completely, then sand the edges lightly to smooth them down and remove traces of glue. Coat with dye as necessary. Once dry, sand and condition the leather to restore finish.