Fabrication Process for Your Granite Countertops

Getting granite countertops installed in your home is a relatively simple process when looked at from the perspective of what you as the consumer can see from beginning to end. Simply put, you call us, select your slabs, & agree on the particulars, then a couple of weeks later they are installed.

There is however a lengthy process involved in getting the stone from its natural state in the earth all the way to your kitchen countertop. The process of turning stone into decorative and functional building materials has been more or less the same for centuries. On the other hand, the equipment has changed dramatically in that time, and the production time greatly reduced.

The process starts at the stone quarry where large blocks are cut from the earth often in a stair-step like pattern. Various types of sawing & cutting methods are used. There are wire saws which are long steel cables with diamond sections embedded in them. These cables are passed through "core holes" which have been drilled horizontally and vertically to a meeting point in the invisible corner of the "bench" to be removed. Then the cable is run through a drive, continuously going deeper into the stone. Core drilling, as mentioned above, coupled with "blasting" is another method of freeing large blocks of stone in this first step of the process. Some quarries use expanding liquid rather than explosives in the core holes-this is for the more fragile stone to keep from fracturing the blocks.

This first step of the process requires very large and heavy equipment to get the granite blocks from the earth and ready for shipping to the "gang" saws. When the blocks arrive at the gang saw operation, the entire block is cut into some 40-60 slabs simultaneously. These blocks are not a standard size, however a rough average would be 6 feet by 6 feet by 10 feet. This would yield 72 one inch thick slabs less the cutting blades, so around 60 slabs. The blades on a typical gang saw are not really blades, they are flat steel material 3" x 3/16 inch thick. They have no teeth or diamond in them. They are mounted on a large rack 2cm or 3 cm apart depending on the desired slab thickness. The rack is wider than the 6 foot wide slab. This rack in turn is mounted to an arm that is attached to the outer side of a massive flywheel creating a back and forth motion of the rack as the wheel is turned by powerful motors.

Once the block has been turned into slabs, the cart holding the 60 slabs is driven on its rail cart to the polishing line. The polishing line is another massive machine with multiple heads driving various grits of grinding and polishing wheels progressing from rough to polish. These heads drive horizontal grinders as the rough slab goes on a horizontal plane slowly through the machine on a conveyor belt. When the slabs come out the other end of the polishing line, they have become polished from their rough state. They are then loaded onto A frames for shipping to the wholesale warehouses throughout the world.

At this point the slabs enter our world here at Alpha StoneWorks, and our turn in the process begins. We come to your home and make an accurate template of your countertop areas. This can easily be done on new cabinets or on top of your existing countertops without disturbing them. After we have made the template, we like to meet with you at our shop for a layout review so we can agree on which portion of the various slabs will go on the different sections of your counters.

Once we have agreed on the layout, we go to word cutting and polishing your countertops. The surface has already been polished or honed, or brushed as the case may be. We cut the counters to match the templates on what is known as a bridge saw machine. This is a large "upside down" table saw. The sawing motor with the diamond blade are suspended above the saw table on the "bridge". This bridge in turn is sitting on two rails some 18 feet apart with rack and pinion drive to move the entire bridge east and west. The motor with blade runs north and south on the bridge via another set of rack and pinion gears. This entire apparatus allows the blade to be positioned anywhere over the 6 foot by 12 foot slab of granite. The saw motor only moves in one straight line, so the table beneath that the slab is laying on rotates in order to allow cuts at any angle needed. The rotating table has positive lock stops at 90, 45 and 135 degrees, and can be locked in any other degree for other cuts as needed. The table on our saw tilts up to nearly vertical via hydraulic cylinders. This makes loading easy and safe for both our workers and for your material. Once the countertop pieces have been cut to size, the edge polishing process begins.

Depending on the configuration of the piece and the desired edge detail, we have several different methods of shaping and polishing them. If they are straight line edges with a flat, beveled, or bull nose shape, they go one our "Pro Edge" machine. This is a machine some 18 feet long, 6 feet wide and around 6 feet tall. It is massively heavy and does the work of two to three men in terms of its output capabilities. You will see both the bridge saw and the Pro Edge in action in the video. If the edges are curved or have jogs in them, these are shaped with routers and grinders. Ogee edge details and other complex shapes of edges are done with large routers.

All through the process we have water spraying on the diamond tooling doing the cutting and grinding. Once the cutting and grinding is done, we proceed with the polishing process. This is done with a series of polishing pads on hand polishing grinders. There are 4 to 8 steps involved in the polishing process depending on the stone type and finish desired. The polishing grits start around 50 grit and go up to 8000 or 10,000 grit. In the case of antique finishes, stiff brushes are used on the grinding machines in place of the polishing pads.

Now that we have your countertops fabricated, it is time to bring them into your home and install them in place. This requires a little brute force and a little experience doesn't hurt a thing! We have learned to work smarter, not necessarily harder, to get the pieces into place. Granite countertops are very heavy to bring in. We use a combination of wheels, ramps, tables and other devices depending on the particular job. The slabs are test fitted then we adhere them to the cabinet tops with the appropriate stone adhesives. Joints are put together with epoxies formulated for stone work. Once the epoxy cures, we dress up the joints and other final details, leaving you with new gleaming granite countertops!