The most time-consuming process in most fabrication shops is sink cut-outs. Most fabricators dread the task of cutting out an under mount sink and then finishing the cutout. Of course, if you have a CNC, Water Jet or any other sink cut out machine the job is much easier. However, there are thousands of fabricators that still do it the old fashion way. For the past 20 years, I have been teaching fabricators a fast and efficient way to cut out and finish an oval vanity sink in less than one hour. Like anything, it is going to take some practice. The following is that technique. This technique applies to stone as well as engineered stone.
Sink Layout and Cutting for Oval Under Mount Sinks.
Materials List
- Template supplied with sink
- White out pen
- Low Contact masking tape
- Alpha AWS 125 saw
- Alpha 5-inch contour blade
- Piece should already be set up on table from edge profiling.
- Sink should not be cut until all edges have been profiled and polished.
- Take templates supplied with sink and place carefully on the desired location for the cutout. Care must be taken so that the template is carefully layouts and that the desired sink will fit into the cabinet. Make sure the sink rim will have enough room so that it does not touch the front rail of the cabinet. In addition, make sure that the fixtures that will be used for the sink have the proper spacing and that there is adequate room for these fixtures. Also, take into accountant the thickness of the backsplash.
- Once the sink template is correctly positioned, trace the outline of the sink with a white-out marker. Care must be taken to make a clean, sharp mark.
- Allow the marked area to dry for several minutes then carefully remove the template.
- Set up the Alpha AWS 125 with an Alpha 5-inch Contour Blade. Make sure that the blade is set up so that the contour(convex side) is facing in toward the motor of the saw. For proper mounting instructions see the instructions equipped with the saw.
- Connect water to the saw and plug the cord into a GFCI equipped outlet. Check the GFC button on the cord of the saw to make sure it is working correctly by pressing the test button. The GFCI device should make a low popping sound when the test button is depressed. If the popping noise occurs, then the GFCI is working correctly. Press the red reset button. Caution: You can only test the GFCI when it is plugged into a live outlet. It will not test properly unless plugged in.
- Adjust the depth of the blade so that it is cutting all the way through the thickness of the stone.
- To start cutting the sink hole take the saw and position it on the inside of the cut line about 1/8 of an inch to the inside. Hold the saw so that the blade is not touching the top. Turn the water on and start the saw by depressing the start button. Slowing plunge the blade into the stone being careful that it does not kick back. Once the saw blade is all the way through the stone, slow push forward following the marked line but staying about 1/8 of an inch inside the line. When cutting tight radius such as a Kohler 2209 or 2210 make sure that the back of the blade does not hit the line as you make the turn. In other words watch both the front and back of the blade as you are cutting.
- Before you reach the end of your cutting make sure there is something under the sink cut out so that it does not fall to the ground. Place a two by four or another supporting device under it.
Finishing Under Mount Sink Cut-outs
Materials List
- Air or electric polisher
- Zero Tolerance bit
- Alpha Ceramic 150 metal bond diamond (four-inch size)
- Alpha Ceramic EX diamond pads in the following grits 200, 500, 1000, 2000, 3000, buff(white and black)
- One Alpha 150 Metal bond Cermamica Pad
- Four-inch flexible pad driver
- Attach a zero tolerance bit to your air polisher.
- Position the polisher and bit so that it is perpendicular to the inside rim of the sink cutout.
- Turn the water on and start the machine. Make sure there is plenty of water supplied to the bit. You may have to supply additional water with a hose so that you do not burn the bit up.
- Start working the bit by pressing it into the stone, working in a right to left pattern. Do not press too hard and make sure your motions are smooth and not jumpy. Keep the bit positioned in a perpendicular position to the top otherwise the rim of the sink will not be even.
- Continue to work the bit until you have reached the marked line. This step is very tricky and requires lots of practice to get a smooth, consistent cut.
- Work the zero tolerance bit until the entire line is even.
- Once you are done with the zero tolerance bit remove it from the polisher and attach a three or four inch Velcro backed drive pad.
- Next you will be smoothing the rim edge with the following Alpha brand diamonds: 150-200-500-1000-2000-3000-buff
- Attach the Alpha 150 grit metal bond Ceramica Diamond to the Velcro backer pad on the polisher.
- Turn the water on and begin smoothing the sink rim by working the diamond back and forth along the rim. This technique will also take practice. I would suggest you review the video that accompanies this manual for the proper technique.
- Work the 150 grit until you get an even, consistent pattern. You will have to blow the area with air to examine it. If may also want to bevel the rim slightly with the 150 grit. If you do this be careful not scratch the top surface. Another method would be to profile the sinks rim with a round-over bit. This should be used right after the 150 grit so you can polish the profile at the same time you polish the sink rim.
- Once the 150 grit is complete, next perform the same process with the 200 grit and then the successive grits. Make sure to use plenty of water and examine your work after each grit is run.
- Once you have finished with the 3000 grit, then attach a black or white buff pad to the polisher. The black pad is used for dark granites, and the white pad is used for lighter granites. For engineered stone stop at the 3000 grit. Do not use the buff pads on engineered stone.
- Add some water to the surface to be worked on. Work the buff pad the same way you did the other grits with the exception of adding no water as you work. In other words, you want to work the buff pad till it is dry.