Quartz countertops have become increasingly popular in kitchen and bathroom remodels due to their durability, low maintenance, and stylish appearance. When it comes to cutting and fabricating quartz countertops, using the proper tools is essential to get clean cuts and avoid damaging the material. Many DIYers wonder if they can cut a quartz countertop using a diamond blade on an angle grinder or circular saw. The short answer is yes, it is possible to cut quartz countertops with diamond blades, but there are some important factors to consider.
Can You Use a Diamond Blade on an Angle Grinder?
An angle grinder with a good quality diamond blade is one of the most common tools used by professional countertop fabricators to cut and shape quartz slabs. Angle grinders allow for straight cuts along edges and custom cutouts for sinks and cooktops. Here are some tips for using an angle grinder to cut quartz:
- Use a diamond blade designed for cutting stone/quartz, usually 4-7 inches in diameter. Do not use a wood or metal cutting blade.
- Select a blade with uniform, consistent diamond segmentation. This will help prevent chipping.
- Work slowly and steadily, without applying too much pressure. Let the blade do the work.
- Keep the blade flushed to the quartz surface and move in a straight line. Lifting or rocking the blade can cause issues.
- Cut just deep enough to score the surface, don’t try to cut all the way through in one pass. Make several light passes to get a clean cut.
- Keep the quartz slab well supported near the cut line to prevent cracking.
- Use a gentle stream of water to keep the blade cool and control dust.
Cutting Quartz with a Circular Saw
A circular saw with a diamond masonry blade can also be used to cut quartz counter slabs. The cutting process is similar to using an angle grinder. The main advantage of a circular saw is the ability to make long straight cuts easily. Follow these tips:
- Use a high quality diamond masonry blade at least 7 inches in diameter.
- Adjust the depth so the diamond segments barely come through the bottom.
- Work slowly with light pressure to score the surface without overheating.
- Make repeated passes until cut is complete. Don’t try to cut all the way through in one pass.
- Support the slab near the cut line and keep the saw base flat and flushed to the surface.
- Use water to lubricate and cool the blade.
Grinding and Smoothing the Cut Edges
Once the main cuts are made, the edges can be smoothed and polished using a hand-held angle grinder and diamond polishing pads. Here is the basic process:
- Start with a 50-100 grit diamond pad to grind and smooth the rough cut edge.
- Move up through the grits to remove scratches – 200, 400, 800, 1500 grit.
- Finish with a 3000-5000 grit “buff pad” and water for a polished edge.
- Take care not to grind too aggressively and overheat or damage the quartz.
- Keep the pads flushed to the edge and move at a steady pace.
- Wet polishing helps cool and lubricate the diamonds.
Cutting Holes for Sinks and Fixtures
Cutouts for sinks, faucets, and other fixtures involve making concentric cuts and interior cutout holes. This takes patience and care. Here are some tips:
- Mark the outline of the hole precisely where needed.
- Use a diamond hole saw or carbide grit hole cutter in an angle drill.
- Cut just deep enough to score the outline of the hole. Don’t try to cut through the full depth.
- Make relief cuts inside the hole outline from the edge to the center.
- Tap out the cutout section carefully with a hammer and chisel.
- Use diamond pads and files to smooth and round the cutout edges.
Cutting quartz countertops with diamond blades and grinders can produce clean, smooth results. The key factors are using quality diamond tooling, working slowly with light pressure, keeping tools cool, and properly supporting the workpiece. Patience and care in following the quartz manufacturer’s recommendations will help ensure successful results. With the right approach, DIYers can cut quartz successfully. However, don’t hesitate to call in a professional fabricator for complex projects or if unsure about any steps.
FAQ about Cutting Quartz Countertops
Can I use my regular circular saw blade to cut quartz?
No, you should never cut quartz with a wood, metal, or masonry blade. You must use a diamond blade specifically designed for cutting stone and quartz.
What RPM should I run the angle grinder or saw at?
Lower RPMs between 4,000-6,000 are recommended for quartz to prevent overheating and chipping. Do not exceed 10,000 RPM.
Is water absolutely necessary when cutting?
Water is highly recommended as it cools the diamond blades, reduces dust, and gives a smoother cut. At a minimum, wet the quartz where you are cutting.
Can I cut quartz with a jigsaw?
It is not recommended to cut quartz with a jigsaw as the up and down motion can chip the edges. Use an angle grinder or circular saw for straight cuts whenever possible.
How long do diamond blades last when cutting quartz?
Diamond quartz cutting blades can last 10-20 linear feet of cutting if used properly. Higher quality blades tend to last longer. Replace sooner if cutting slows or chipping occurs.
How deep of a cut should I make in each pass?
Only cut 1/16 to 1/8 inch deep per pass. Trying to cut too deep will overload the blades and cause issues. Take multiple light passes for best results.
Should I use any sealant on cut quartz edges?
Sealants are usually not needed on quartz cuts. However, you can apply a stone sealant for extra protection if desired, especially around sinks and faucets.
What’s the best way to make curved or rounded cuts in quartz?
Use diamond grinding or sanding pads on an angle grinder. Start with a coarse 50-100 grit pad and work up to finer pads for a smooth curved edge.
Can I do quartz cutting outdoors?
It’s best to cut indoors to contain the dust. If cutting outside, try to direct the water and dust away from the work area to improve visibility.