Grind granite from coarse to fine

Granite is one of the hardest rocks available. The grinding is correspondingly time-consuming. The work takes a long time, is exhausting and consumes a lot of abrasive. Freshly cut granite retains its shine and intact surface for a long time after sanding.

From the rough to the ever finer

The transitions from grinding to polishing granite are fluid. Depending on the surface condition, the grain size is selected for sanding granite. As a rule of thumb, if after the thorough cleaning of the surface individual mica elements, the biotite, already shine, can be started with 400 grit. For pale colors and lack of highlights or mica effects, starting with 200 grit is recommended.

When grinding granite, several operations with finer grain sizes have to be planned. From an 800 grit experts speak of polishing. The colors and textures appear delicately drawn and the granite is covered by a continuous shine. Whether an even higher grain size such as 1200 is used or is converted to the final polishing, for example, with lambskin, is an individual decision.

Grind granite step by step

  • water
  • polishing paste
  • Adjustable flex or
  • floor grinder
  • Grinding wheels 220, 400, 800 and 1200 grit
  • Lammfellpad
  • Eye mask
  • respiratory protection
  • ear protection
  • vacuum cleaner
  • Rag or mop

1. Pre-clean

Remove coarse dirt, sand and dust without residue. If you wipe, allow the granite to dry completely before sanding.

2. Determine starting grain size

In most cases, laid granite is ground with 400 grit. Do a short sanding test at a hidden spot. Sand a few square centimeters and compare the reflective effect of the surface with the environment. If the ground point reflects much stronger, the starting grain size can be reduced to 220.

3. Slip on the grinding wheel

For floor grinding machines or flexes, the grinding wheels are fixed on a Velcro surface. Choose your grain size and fix the disk centered on the sanding pad.

4. First cut

Set the lowest possible speed on your machine as the speed. It must not be higher than three thousand revolutions. Start the machine and set the grinding wheel horizontally on the granite after reaching the speed. Grind in circling movements without jamming. Repel again and again and let the stone and machine cool down.

5. Remove dust

When your first sanding pass has been completed, thoroughly remove the sanding dust on the granite. After drying, sand down areas that have irregular and visible marks and marks.

6. More cuts

Repeat the Ankletten, the grinding and the cleaning with the abrasive of the next higher grain size.

10. Polishing

After sanding with 800 or 1200 grit, you can use the lambskin pad and polishing paste to complete the final polish.

Tips & Tricks

When leasing machines, make sure that the speed is adjustable. There are irregular floor grinders and flexes that are not suitable for grinding granite.

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