Things You'll Need
Safety goggles or face shield
Leather work gloves
Hard wire cutter
Granite installers set countertops in sections and use a two-part epoxy or a polyester-based adhesive to secure slabs that butt up to each other. Typically, silicone holds the granite slab to the base. Two-part epoxy adhesive fills the gaps, seams and joints and forms a secure bond that can be difficult to break without damaging the granite. Many homeowners reclaim discarded granite countertops to install in their home, which requires separating the countertop pieces.
Lay strips of masking tape on each side of the seam to protect the granite surface.
Place a metal straightedge next to the seam and drag the edge of a utility knife along the seam to score the epoxy.
Measure the length of the seam with a tape measure and add 24 inches to the measurement. Note the measurement.
Put on safety goggles or a face shield and leather work gloves. Have your helper do the same.
Cut a piece of piano wire to equal the seam's measurement with a hard wire cutter or a cutoff wheel attached to a hand-held rotary tool.
Pour water across the seam.
Grip 1 to 2 inches from the end of the piano wire with locking vise grips and lock the grips. Have a helper do the same.
Hold the vise grips and have the helper hold the second pair of vise grips. Lay the piano wire in the scored line with the helper directly across the countertop from you pulling the piano wire taut.
Pull the piano wire across the seam while pushing it down into the adhesive until the helper's end reaches the countertop. Have the helper pull the piano wire while pushing it down into the seam until you reach the countertop. Continue this sawing action until the piano wire cuts through the adhesive.
Clean the countertop seam with an all-purpose cleaner and a rag to remove oils, grease or other flammable substances.
Put on safety goggles and leather work gloves.
Wave the heat from a heat gun over a 6- to 8-inch section of the seam until the adhesive begins to soften.
Draw a utility knife along the heated section of adhesive, cutting through the adhesive. Scrape as much adhesive out of the seam as possible with the blade to prevent the adhesive from hardening and setting.
Move the heat gun back and forth along the next 4- to 6-inch section of seam until the adhesive softens. Cut through the adhesive and scrape it out of the seam. Continue moving along the seam, heating the adhesive, cutting and then scraping.
Go back to the first 4- to 6-inch section and heat it again until the adhesive deeper in the seam becomes soft.
Extend the length of the blade on the utility knife. Cut through the adhesive and scrape out excess material. Continue to move down the length of the seam, cutting and scraping adhesive from the gap until no adhesive holds the granite together.
Apply heat to short, manageable sections. Test the effects of heat on the granite countertop in a hidden area.
Do not snap, whip or otherwise play with piano wire. Never wrap piano wire around a hand or other body part when cutting. Heat may discolor the granite if it becomes too intense.