How to cut porcelain stoneware with a grinder

Recommendation points

• Why porcelain stoneware is so difficult to process
• Tools and supplies
• Cutting
• Curve cuts and burrs

Porcelain stoneware is one of the most durable building materials, difficult to process due to its strength and hardness. However, the need to process such tiles inevitably arises, for which a certain set of technical means is used..

Why porcelain stoneware is so difficult to process

The structure and physical and mechanical properties of porcelain stoneware do not allow processing it with a wide range of tools. Despite the absence of the glaze familiar to many on the surface, the formation of chips is very likely during the cutting process, spoiling the appearance of the edge.

In production, the highest quality brands of porcelain stoneware undergo rectification: the tiles are driven into size by water-jet cutting, eliminating the size discrepancy and curved edges. The same method can be used for cutting porcelain stoneware at the installation site, for which it is very convenient to use electric tile cutters, in which the lower part of the diamond disc is immersed in a bath of water.

An alternative way is to use a special type of manual cutter. Do not be surprised, but even with a thickness of 30–40 mm porcelain stoneware, such a tool copes well with its processing, forming an even edge without chips. This is because the material has a high homogeneity of the structure and, after applying the serif, behaves in the same way as ordinary ceramic tiles..

Both methods described above have a significant drawback: they require the use of special equipment, which costs a lot of money and cannot be used anywhere else. Therefore, for a home craftsman who intends to lay out an entrance island in the hallway from porcelain stoneware, buying a tile cutter is not an option..

Tools and supplies

Nevertheless, there is a way out, for example – angle grinder with a diamond disc for stone and concrete. But do not rush to get to work, because there is a certain specificity both in the processing technique and in the choice of the appropriate equipment.

Let’s start by understanding which grinder is best to use. We dismiss the options for 230 mm discs right away: the tool is too heavy and cumbersome, poorly controlled during operation. A 180 mm angle grinder can be used, but only if a sufficiently thick porcelain stoneware is cut, where a significant disc overhang is required. The best option is a grinder with a 125 mm disc, which can be held with one hand during operation. Even if the effective cutting depth of 40 mm does not cover the thickness of the porcelain stoneware, it’s okay. Practice shows that if you made a cut for more than half the thickness, the material breaks off perfectly along the cut line, afterwards it is enough to only slightly process the edge.

Now about the diamond discs. For cutting porcelain stoneware, do not choose segment wheels designed for dry operation. Solid discs with stepped edge notches are ideal, but you need to make sure that the permissible speed of the diamond wheel matches the parameters of the tool.

In addition to a grinder with a diamond wheel, you will need some more accessories. First of all – a plastic bottle with a pierced cap and a piece of thin silicone tube inserted into it. The cutting of porcelain stoneware must be done with a constant supply of a small amount of water, otherwise the spraying on the disc will not last long. You will also need a pair of quick-clamping clamps and a piece of steel angle with a shelf of 25 mm, the length of which is 15-20 cm longer than the cutting line.

Cutting

If everything is ready, you can get to work. The cutting line must be marked with a marker, after which the tile is laid on a table or stool so that the marking is entirely above the supporting surface. Exactly along the cut line, a corner is applied from above, the vertical shelf of which should be facing the trimming side. On both sides, the corner is pressed with clamps to the edge of the table, thus, the porcelain stoneware will be securely fixed, and the outer side of the shelf will act as a guide for making a direct cut.

Do not forget about safety precautions: it is strictly necessary to use protective glasses, gloves and earplugs. The included grinder must be held in such a way that the disc is located almost parallel to the corner shelf, deviating from its edge by 1–2 mm and adjoining closely at the bottom. A thin groove is applied to the surface of the porcelain stoneware by moving towards itself. It is not necessary to exert strong pressure, just scratch the surface a little. After that, the cutting line should be slightly sprinkled with water and again make a shallow cut with a movement towards you.

This must be repeated over and over again, carefully making sure that there is always water in the cut. When the tile is cut to 2/3 of the thickness, you need to remove the clamps and remove the corner. The tile should be positioned at the edge of the table, trimmed until a gap is formed, and then lightly hit with the palm of the hand on the part to be cut. If the cut is narrow, you can break it off with pliers..

With this technique, cutting porcelain stoneware creates a clean and straight top edge, but chips may form at the bottom of the cut end. To remove them, the tiles must be turned inside out and laid on the table so that they hang slightly from the edge. After that, with the same diamond disc, you should gradually grind the edge, while wetting the edge is not necessary.

Curve cuts and burrs

In conclusion, we will highlight such an issue as making a curvilinear cut, chamfering and gouging to flatten tiles at corners without using a docking profile. With a burr, everything is quite simple, for its implementation you need a rigid diamond cup with large segments. The tile must be laid with the back side up and draw a line parallel to the edge with an indent equal to the thickness of the tile. After that, using a cup, gradually cut the corner, ensuring that the marking line connects to the front edge with one straight edge. Periodically, the place of grinding should be moistened with water..

Chamfering the front side is more painstaking work. Here it is necessary to use the AGShK, in the common people – turtles. Manufacturers do not recommend using them for edge stripping, but with increased care this can be done, it is only important not to put excessive pressure on the tool. Hard cups are poorly suited for this: they have rather large gaps between the segments, which causes chips and scratches on the surface. But with due diligence with turtles, you can remove a chamfer that is practically indistinguishable from the factory one, you should only reduce the graininess during the final processing.

To make a curved cut, first remove as much material as possible with a conventional diamond blade. With convex edges, this is quite simple; to cut concave ones, you have to divide the cut into sectors and then delete it in fragments. The edge of the porcelain stoneware is then smoothed using a hard diamond cup.