Grinding granite - A guide to do it yourself
Figure 1: Sanding granite takes a lot of patience and time!
1. Grind granite yourself - that's how it works
Before you start grinding granite, you should get various working materials in the form of tools and machines in advance. Certain protective equipment is also necessary to avoid any damage to health during this activity.
1.1 What is required to grind granite?
Since granite is a hard natural stone, grinding granite requires a lot of patience and time. However, the stubborn work pays off, so that the sanded surface can once again impress with its luster. However, in order not to endanger your own health while grinding granite surfaces, certain protective equipment is essential due to the high level of dust formation. This includes, for example, the respiratory mask, safety goggles and hearing protection.
In addition, certain working utensils in the form of machines, tools and cleaning equipment are required for the "granite grinding" project. For large surfaces such as a floor, you should get a floor grinder. You can use an angle grinder for small areas such as a kitchen worktop or a window sill. You can usually buy or rent these devices at any large hardware store. Since several operations are required to successfully grind granite surfaces, grinding wheels with different grits are required for this . The cleaning equipment includes a vacuum cleaner, a broom and a cloth. You need this when cleaning the surface between the different sanding processes. To finally bring your granite surface to a high gloss, you need a lambskin pad and polishing paste for polishing.
Summarized here again:
- respirator
- safety goggles
- ear protection
- angle grinder
- Grinding wheels from 220 to 1200 grit
- Vacuum cleaner
- Broom
- rag
- lambskin pad
- polishing paste
- If necessary, diamond grinding disc for untreated granite
1.2 What grit do I need to grind and polish granite?
As a rule, you are well equipped with the grinding wheels 220 grit, 400 grit, 800 grit and 1200 grit to achieve a successful grinding result. You need these different degrees of granulation because of the several work processes that are necessary, for example, to give the granite surface of your old kitchen worktop or window sill its familiar look again. Optionally, after sanding with the 1200 grit, you can use a lambskin pad and a suitable polishing paste to literally give the surface the final touch.
1.3 How much does granite grinding and polishing cost?
The costs for grinding and polishing granite depend on the size of the area to be processed on your object. If your project is a worktop from the kitchen with a size of 2m², you can count on about 70 - 100 euros. Here are the costs listed in more detail:
Personal protective equipment (approx. 27 - 43 euros):
- Respirator mask approx. 20 – 30 euros
- Safety goggles approx. 1 – 3 euros
- Hearing protection approx. 6 – 10 euros
Machine rental from a hardware store (approx. 12 euros):
- Angle grinder approx. 12 euros (daily rate)
Tools (approx. 23 euros – 37 euros):
- Grinding wheel set (220 grit – 1200 grit) approx. 10 – 15 euros
- Lambskin pad approx. 8 – 12 euros
- Polishing paste approx. 5 - 10 euros
Cleaning utensils (approx. 7 euros):
- Rag about 2 euros
- Broom about 5 euros
Prices are from current internet research (November 15, 2022).
2. Grinding and polishing granite yourself - step-by-step instructions
Granite is one of the hardest stones found in nature. Therefore, one should be aware in advance that grinding and polishing the surface involves stubborn work combined with a lot of time and patience. However, this effort is worthwhile when you look at the new surface, as the full optical potential of the natural stone can come to light again in the form of gloss and intensively shining colors. In our step-by-step instructions, you will find out how you can achieve successful surface results when grinding and polishing granite.
Figure 2: Do your own granite grinding with this guide
2.1 Preparation
Before you start grinding, you should put on the respirator and safety goggles due to the high dust development. In addition, to be on the safe side, you should also put on hearing protection in view of the high noise level during grinding. Have all machines and tools, as well as all cleaning utensils for work, ready to hand.
2.2 Cleaning the surface
First clean the surface with a vacuum cleaner or broom so that it is free of particles in the form of coarse dirt, sand and dust. Then wipe the surface to be treated thoroughly with a damp cloth.
Important: The cleaned surface must be dry before sanding!
2.3 Determine grit
Start by choosing the grit of the grinding wheel. You can determine this with a small sanding test on the surface, in which a small area is sanded with a 400 grit. If the sanded area is significantly shinier than the area next to it, you can start with a 220 grit.
2.4 The grinding pass
After selecting the grit grade of the grinding wheel, you can start grinding. Set the speed of the angle grinder to the lowest possible speed so as not to heat up the grinding wheel and place it horizontally on the surface. Slowly work your way across the entire surface in a circular motion. Make sure that the sanding disc does not tilt during sanding.
2.5 Remove sanding dust
After completing the grinding pass, the surface must be cleaned again. Thoroughly clean the surface again with a damp cloth. As soon as the surface is dry again, irregular areas in the form of grooves or scratches can be repaired by regrinding.
2.6 More grinding passes
Repeat steps 4 through 6 of this guide. Change to the next higher grit with each successful sanding pass.
2.7 Granite Polishing
Depending on the desired result, after reaching the 800 grit or the 1200 grit, the surface can be polished to a shine using a lambskin pad and a polishing paste. Apply the polishing paste to the surface and polish it with circular movements.
3. Conclusion: grinding granite
Grinding granite is a strenuous activity due to the hard natural stone. However, this can be done successfully with a lot of time and patience. Machines and tools such as angle grinders, floor grinders and grinding wheels with different grit grades are necessary for the successful grinding of granite.
4. FAQ - The most frequently asked questions about grinding granite
1. How long does it take to grind granite?
The duration of the grinding process depends on various factors, such as the size and condition of the granite to be machined. However, it typically takes anywhere from several hours to a day to grind an average granite surface.
Our experience shows that the often large number of grinding passes with different grits ensure that a long working time is achieved when grinding granite.
2. Is sanding granite a dusty job?
Yes, grinding granite creates dust. It is important to take appropriate protective measures during the grinding process, such as wearing safety goggles and a respirator. A vacuum cleaner or wet and dry vacuum cleaner can be used to suck up the resulting dust.
3. Can I grind granite myself or should I hire a professional?
It is possible to grind granite yourself if you have the necessary tools and knowledge. However, if you are unsure or inexperienced, it may be wise to hire a professional for best results. A first point of contact for this would be MyHammer. An online platform for placing experts in all major German cities.
4. How often should I seal cut granite?
The frequency of granite sealing depends on the use and stress on the surface. In general, it is recommended that honed granite be resealed every 1-3 years to maintain its durability and overall beauty.
5. Can granite be damaged again after grinding?
Yes of course! In our opinion, once cut, granite can be re-damaged in many ways, most notably by sharp or abrasive objects. But the offspring can also cause creative damage.